Occupational Safety and Health Administration OSHA

Hazard Communication in the 21st Century Workplace

March 2004
Executive Summary

Over 30 million American workers are exposed to hazardous chemicals in their workplaces. The Occupational Safety and Health Administration's (OSHA) Hazard Communication Standard (HCS) is intended to ensure that these workers and their employers are informed of the identities of these hazardous chemicals, associated health and safety hazards, and appropriate protective measures. The HCS covers some 650,000 hazardous chemical products found in over three million establishments.

Since the HCS was adopted 20 years ago, the availability of chemical information in workplaces has increased dramatically, and the provision of labels and MSDSs with products has become a standard business practice. Surveys have shown that employers rely on MSDSs to select less hazardous substitutes, as well as to help them identify appropriate protective measures. In addition to these workplace uses of hazard information, MSDSs have evolved into sources of information on other aspects of chemical use.

While the standard's successes are evident, there are concerns regarding the quality of information disseminated under the HCS, in particular, whether the information is consistently accurate on MSDSs. This review examines the issues raised, as well as the underlying causes. It also describes a new OSHA hazard communication tool kit to address these issues that includes a balanced range of initiatives:

  • Substantive guidance to assist employers to evaluate hazards; provide worker training; and prepare MSDSs;

  • Implementation of an alliance with the Society for Chemical Hazard Communication, a professional society with expertise in the development of labels and MSDSs;

  • An enforcement initiative to identify critical information on a number of chemicals for OSHA's compliance staff to use when reviewing MSDSs for those chemicals in the workplace, supplemented by development of an MSDS review tool and compliance staff training;

  • A portal page on OSHA's web site that consolidates these and other hazard communication resources, and makes them accessible from a button on the home page; and,

  • Consideration of implementation of the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) as a longer-term approach to improving hazard communication. The GHS includes provisions that address comprehensibility issues regarding hazard communication, including standardized approaches to labels and to MSDS format.

Table of Contents

Material Safety Data Sheets
Considerations Regarding MSDS Format
National Advisory Committee on Occupational Safety and Health Review
Development of the GHS
What Can Be Done to Address Hazard Communication Issues
Appendix re: Studies/Investigations on Hazard Communication


When OSHA published its Hazard Communication Standard (HCS) on November 25, 1983, it was the culmination of 10 years of difficult rulemaking activity that included a rulemaking Advisory Committee, an aborted plan to do joint rulemaking with EPA, and a withdrawn proposal. There were many who felt that while the intent was important, the complicated technical and legal issues that would have to be resolved to accomplish it would keep OSHA from completing a rule in this area.

OSHA persevered with the support of many in industry and labor to adopt a standard that was unique in many respects. The rule requires chemical manufacturers and importers to evaluate the hazards of the chemicals they produce and distribute. The information about the hazards and associated protective measures is required to be disseminated on container labels and material safety data sheets (MSDSs). All employers with exposed employees are required to provide access to the labels and MSDSs, and to train workers. Important aspects of the HCS and its implementation include the following:

  • It is generic and performance-oriented -- all chemicals are covered
  • It is criteria-based, not limiting coverage to a list that can become outdated
  • It incorporates a downstream flow of information from producers to users
  • Trade secrets have been addressed to ensure protection of legitimate claims while requiring disclosure where necessary for health and safety
  • It has an impact on interstate commerce and international trade
  • It interfaces with other Federal requirements for classification and labeling
  • It is designed in part on communication theory in addition to technical data, and the concept of modifying behavior through transmittal of key information

The HCS requirements are as important to the 21st century workplace as they were 20 years ago. Chemical information is the foundation of workplace chemical safety programs -- without it, sound management of chemicals cannot occur. While the rule has been amended since 1983 to broaden the coverage to include all workers exposed to chemicals, as well as evolved to reflect new technology in information dissemination and other developments, the basic approach is still sound. The HCS has made provision of hazard information about chemical products an accepted business practice in the United States. There is a whole generation of employers and employees now who have never worked in a situation where information about the chemicals in their workplace is not available.

Because of its broad scope and significant impact, the HCS has continued to be a subject of discussion and debate over the 20 years it has been in place. Implementation of the standard has not been static -- OSHA has reviewed many situations that have arisen, and modified its guidance and practices over the years to reflect lessons learned. For example, when the standard was promulgated, MSDSs were always prepared and transmitted as paper copies. With the increased availability of computers, OSHA revised its standard and its compliance directive to allow electronic transmission and access under specified conditions. Most large companies use electronic systems today.

The Agency has not, however, made any major changes to the rule itself since broadening the scope to all employees exposed to chemicals. OSHA has actively participated in the development of an internationally harmonized approach to the issue. OSHA has contributed our lessons learned to that process, and believes that the new system builds on our successes but also addresses some of the concerns that have been raised in discussions in the US. The Agency has been mindful of the fact that any modifications to labels and MSDSs will be costly and time-consuming, as well as being associated with a very large paperwork burden. Therefore, any such changes should be considered very carefully in terms of the benefits that would accrue as a result.

The current activities related to Hazard Communication began in mid-2002 when OSHA formed a new Directorate with responsibility for both standards and guidance. Hazard communication was one of the subjects that was identified as being appropriate for the development of guidance, and we contracted to finish two guidance documents that were initiated by recommendations from our National Advisory Committee on Occupational Safety and Health (NACOSH). In addition, work was started on a new guidance document for the preparation of MSDSs. The international system was nearly complete, so we also began to prepare a guide to that system that could be used for awareness raising as the United States considers whether to implement it.

Subsequently, in response to correspondence regarding the accuracy of material safety data sheets (MSDSs) prepared by chemical manufacturers and importers under the requirements of the HCS, the Secretary of Labor asked Assistant Secretary Henshaw "to review the current requirements and to recommend whether changes should be made."

The standard addresses accuracy in the requirements for MSDSs, as well as requiring MSDSs to be updated when there is new and significant information regarding the hazards or ways to protect against the hazards. The following provision is found at 29 CFR 1910.1200 (g)(5):

    The chemical manufacturer, importer, or employer preparing the material safety data sheet shall ensure that the information recorded accurately reflects the scientific evidence used in making the hazard determination. If the chemical manufacturer, importer or employer preparing the material safety data sheet becomes newly aware of any significant information regarding the hazards of a chemical, or ways to protect against the hazards, this new information shall be added to the material safety data sheet within three months.

The issue regarding accuracy involves the extent of compliance with this and other provisions of the rule rather than the requirements of the rule itself. Therefore, OSHA has taken this opportunity to complete a wider consideration of the subject of hazard communication in general, and MSDSs specifically, to identify why these accuracy issues are occurring and determine where improvements can be made. The Agency has also initiated work on a number of different activities to address these and other concerns we have identified.


Chemicals are ubiquitous in the workplace environment in the United States and other countries. It has been estimated by OSHA that there may be as many as 650,000 hazardous chemical products in use in the US. The HCS applies to over 3 million American workplaces, and over 30 million potentially exposed workers.

The broad scope of chemical exposures poses a challenge to OSHA in terms of worker protections. Traditional standards that address a single chemical in detail, including establishing an occupational exposure limit, have been one approach. But the Agency will never have the resources to address all chemicals this way, or even all significant chemicals. From the first years of OSHA rulemaking, the Agency has explored other means to address worker protections.

The HCS is a generic standard that covers all hazardous chemicals as well as all workplaces where they are used. The concept behind the HCS is that providing information to employers and employees enables them to take steps to ensure protection in their workplaces. It works to reduce illnesses and injuries when employers and employees modify their behavior as a result of receiving the information about the hazards.

Employees have a right-to-know the hazards and the identities of the chemicals they are exposed to under the requirements of the HCS. But equally important in terms of worker protection is that employers have access as well. Before the HCS was promulgated, some companies provided such information voluntarily to their customers. But the quality of it ranged significantly, many trade secrets were claimed, and the delivery of it was inconsistent.

The most important way that the HCS works today to reduce chemical source illnesses and injuries is to ensure that workers and those who provide protections for workers - physicians, nurses, industrial hygienists, safety engineers and other professionals - have the information they need about the chemical to devise protections. Selection of appropriate engineering controls, personal protective equipment, and controls such as substitution, is predicated on knowing what chemicals are present, what form they are present in, and what their hazardous effects are, including physical and chemical characteristics.

In preparing the HCS, OSHA examined industry programs and built the requirements of the standard to take advantage of those good practices already in existence in industry. As a result, the HCS incorporates a 3-pronged approach: labels on containers, development of material safety data sheets, and employee training.

Each of these elements is interdependent - they do not stand alone as a mechanism to communicate information. A label is the most immediate source of information. The statement of hazards is brief. It is on the containers in an employee's work area and therefore accessible at all times. It is intended to be a snapshot to remind the worker that the materials are hazardous, and that more detailed information is also available on the MSDSs and in the training they receive.

MSDSs are reference documents. They are basically a one-stop shopping source for everything you might need or want to know about a chemical. As such, they must be useful to the safety and health professionals deciding what controls to use, the first aid or medical treatment to provide, and the precautionary measures to follow. While available to them, much of the information present on the MSDS is not primarily written for workers but for other audiences. Because the audience is generally safety and health professionals, the information on MSDSs is usually technical. Such MSDS users need to have the specific data on the hazards of a chemical in order to use it for their purposes. For example, while a worker may need to know that a chemical is acutely toxic, the health professional may also want to know the basis for that classification, i.e., information on the dose at which the chemical can cause a fatality.

Training of workers is essential to ensure that they understand the information provided, where they can get more information, and how they can use the information to protect themselves. Since labels and MSDSs are based on hazard information, training is also the means an employer can use to address risk related to the workplace situation involved.

These three aspects work together to provide a complete approach to hazard communication, ensuring that the information is provided in different ways to reinforce and explain it to those exposed. This comprehensive approach to hazard communication was based in part on information about communication theory that was identified during the rulemaking. For example, the more information that appears on a label, the less likely it is that someone will read it and use it. Therefore, the label requirements were kept to a brief minimum to enhance their utility and additional information was provided for reference on MSDSs.

Material Safety Data Sheets

As has already been described, MSDSs are one part of the approach to hazard communication and are not a stand-alone communication mechanism for workers. Since the focus recently has been on MSDSs, it appears useful to review them in somewhat more detail.

Rudimentary forms of MSDSs on chemicals have been available since the 19 th century, and some trace their history back to hieroglyphics on the inside of Egyptian pyramids about the effects of various chemicals. The modern MSDS started becoming available from the chemical industry in the 1940's and 1950's, with the first regulatory requirements adopted by the former Bureau of Labor Standards for the maritime industry before the OSH Act was adopted.

The MSDSs available at the time the HCS was adopted followed various formats. Those chemical manufacturers who already provided MSDSs were most concerned during the rulemaking that they not be required to change what they were already doing voluntarily in terms of a format. OSHA thus adopted a performance-oriented requirement that allowed any format to be used as long as all of the information required appeared on the form. But the HCS also required more extensive information be provided than had been previously, particularly on health effects. The two-page format that was common in the past is rarely used now, with most MSDSs being a minimum of 4 pages and many exceeding that number.

Today's 21 st century MSDSs are an accepted business practice for the chemical industry, and are featured in their Responsible Care programs. They are used worldwide to transmit detailed information about a chemical, how it should be used, its effects, how to protect against those effects, what regulations apply to the chemical, and other information. Most employers have requirements for MSDSs for everything they purchase, including products that are not hazardous under the HCS. Many employers routinely review MSDSs before they purchase a chemical, and compare it to acceptable alternatives in order to ensure the least hazardous material is used. This is one of the most important uses of such information since it prevents exposure from ever happening when properly employed. They are also widely used to determine what protective measures should be implemented, such as what respirator to select to protect exposed employees or what type of glove material is required to prevent skin exposure.

The utility of MSDSs has been demonstrated repeatedly. However, a number of studies and investigations that have raised the concern that some MSDSs may be incomplete or contain erroneous or out-of-date information. OSHA has reviewed the available information on MSDSs and other hazard communication aspects, and summarizes the findings of them in the Appendix to this document. While this information indicates there are inaccurate MSDSs in circulation, there has never been a comprehensive study on this topic that provides more than anecdotal evidence about a limited number of MSDSs.

This is not surprising since a study of that magnitude would be far-reaching, costly, and time-consuming. However, lacking such a study, it is difficult to determine how widespread the problem is today. The studies described are quite old in some cases. In others, the authors have made assumptions about what they consider to be compliance with the standard that may not be consistent with the standard's requirements. For example, in a study regarding MSDSs on toluene diisocyanate, the authors assumed the MSDS was inaccurate if it did not explicitly refer to occupational asthma but discussed respiratory sensitization. Since respiratory sensitization is the health hazard defined in the HCS, either term would be accepted as compliance for OSHA.

The role of product liability laws in the United States should also be mentioned with regard to the accuracy of MSDSs and labels. Producers of chemicals may be subject to "failure to warn" suits that can have significant financial implications. These US legal requirements affect the length and complexity of MSDSs, as well as the way in which information is presented.

In addition to the issue regarding accuracy, there have been concerns that the MSDSs are not comprehensible to employees. This criticism results in part from the fact that MSDSs are written for a number of different audiences, and thus may include technical information not intended primarily for workers. It is important to emphasize that others parts of the HCS--the label and training--are critical to employees receiving and using the appropriate information on a chemical.

From our experience in this field we have determined that there are a number of reasons for these inaccuracies and comprehensibility issues that cannot necessarily be solely derived from the anecdotal evidence described in the Appendix:

  1. Document Design Principles

  2. The MSDS has multiple audiences for its information - workers, employers, safety and health professionals under OSHA requirements. In addition, Title III of the Superfund Amendments and Reauthorization Act (SARA, also known as the Emergency Response and Community Right-to-Know Act of 1986) mandated that MSDSs be made available to state emergency response commissions, local emergency planning committees, and fire departments in order to assist in planning and response to emergencies, as well as to provide members of the general public with information about chemicals used in their communities. It is difficult, if not impossible, to design a document that meets the informational needs of all of these audiences while being comprehensible to all as well. On the other hand, requiring the production of multiple documents so each audience can be addressed separately would greatly increase the cost and paperwork burdens of the standard. Therefore, while some information can be made available to MSDS preparers that will help improve the communication aspects of MSDSs, it is not realistic to expect that MSDSs will ever be able to provide all of the information needed as well as be comprehensible to all audiences.

    There have been suggestions that two MSDSs be distributed, one for workers and one for the other audiences. There are a number of problems with this approach. First, the label already provides a simple and immediate summary of the hazards, and training is conducted to help ensure that workers understand the available information. In addition, the 16-section MSDS is designed to have the information that workers and emergency responders need in the first few sections. Having a second MSDS would simply duplicate these requirements and double the paperwork requirements for each chemical.

  3. Qualification of MSDS Preparers

  4. The HCS does not address what qualifications are needed to prepare MSDSs. Accurate depiction of health effects in particular, as well as other information such as first aid, requires a technical background that involves review and interpretation of available data. Large chemical manufacturers often have a staff of experts devoted to the preparation of accurate labels and MSDSs, with a variety of disciplines involved in the process. Smaller chemical manufacturers often do not have such resources. They may choose to use consultants who do have the background, or they may complete the MSDSs themselves. The disparity in the qualifications of MSDS preparers is one significant reason for the disparity in the quality of the MSDSs. There are no degrees in this type of product stewardship work so experts in label and MSDS requirements usually come from backgrounds such as chemistry and industrial hygiene, and receive on-the-job training. The primary source of specific training in this area is from a professional society, the Society for Chemical Hazard Communication, which has a series of professional development courses devoted to preparing labels and MSDSs.

  5. Inadequate Information Available on Chemicals

  6. The HCS is based on identification and transmittal of available information on chemicals. However, there may be limited information available on all the aspects of a chemical's effects, particularly in the area of chronic health effects. Many aspects of protection have not been studied either. For example, there are no OSHA requirements for chemical manufacturers to test their chemicals for permeability through glove materials. While many such tests have been performed voluntarily in recent years, there are many chemicals for which they have not been done.

    In addition, most products marketed are mixtures of chemicals that are often unique to a single manufacturer. Mixtures are tested less frequently than individual chemicals are, and there is often limited information available to predict how mixing the chemicals affects their overall effects and what protective measures should be used. The HCS covers mixtures in a conservative way, requiring the chemical manufacturer to consider the mixture to have the same effects as its hazardous ingredients in most situations. Where mixtures are complex, with numerous ingredients, the MSDSs are complicated as well and the user is required to make some judgments about how to apply the information in their own workplace situation.

    Thus the state of the art on chemicals affects the quality of the information on the MSDSs. Even the best available evidence may not provide sufficient information about the hazardous effects or the way to protect someone from experiencing them. OSHA representatives have had informal discussions with other countries that have MSDS requirements, and they all report similar situations with regard to accuracy of MSDSs.

Considerations Regarding MSDS Format

As noted above, when the HCS was initially promulgated, the record supported having a performance-oriented format to accommodate existing MSDSs. However, as the scope of the standard broadened to include workers outside of manufacturing, and EPA's requirements extended the use of MSDSs to non-workplace settings, the need for a standardized approach was raised.

To accommodate the needs of these diverse groups, a standardized format was seen as a way to make the information on MSDSs easier for users to find, segregate technical sections of the document from more basic elements, facilitate computerized data retrieval systems, and simplify training for workers who use MSDSs. To assist manufacturers and importers who desired some guidance in organizing MSDS information, OSHA established a voluntary format for MSDSs in 1985 (Form 174). This 2-page form includes spaces for each of the items included in the MSDS requirements of the standard, to be filled in with the appropriate information as determined by the manufacturer or importer. However, some members of the regulated community desired a more comprehensive, structured approach for developing clear, complete, and consistent MSDSs.

In order to develop this structure, the Chemical Manufacturers Association (now known as the American Chemistry Council) formed a committee to establish guidelines for the preparation of MSDSs. This effort resulted in the development of American National Standards Institute (ANSI) standard Z400.1, a voluntary consensus standard for the preparation of MSDSs. Employers, workers, health care professionals, emergency responders and other MSDS users participated in the development process. The standard established a 16-section format for presenting information as well as standardized headings for sections of the MSDS. By following the recommended format, the information of greatest concern to workers is featured at the beginning of the data sheet, including information on ingredients and first aid measures. More technical information that addresses topics such as the physical and chemical properties of the material and toxicological data appears later in the document. The ANSI standard also includes guidance on the appearance and reading level of the text in order to provide a document that can be easily understood by readers. OSHA allows this format to be used to comply with the HCS as long as it includes all of the required information.

A separate ANSI standard, Z129.1, was developed for labeling of hazardous chemicals. This too gives employers guidance on how to provide information on a label, including standardized phrases and other information that can improve the quality of labels. Because they are voluntary standards, however, the ANSI approach has not been adopted by all chemical manufacturers and importers. As a result of the diverse formats and language used, consistent and understandable presentation of information has not been fully achieved.

OSHA issued a Request for Information (RFI) in the Federal Register on May 17, 1990 (55 FR 20580) and received about 600 responses. The key issue for commenters was adoption of a standardized format or order of information for MSDSs. There was support expressed for the ANSI 16-section format as well. International discussions were ongoing at that time in the International Labor Organization, and in 1990 ILO adopted a recommendation for a 16-section MSDS format consistent with the ANSI standard. In addition, the European Union also adopted a 16-section format that was similar, Canada recognized the format as being compliant with their rules, and ultimately, the International Standards Organization (ISO) adopted such a standard as well.


While labels have not been a focus of recent discussions, they are an important aspect of hazard communication. OSHA's requirements are performance-oriented, so employers may choose how to convey the hazard information on the label. Many follow the suggestions of the ANSI labeling standard in terms of language used to convey the hazards, but others do not. As a result, workers see different statements to convey the same information from different suppliers. And smaller employers have the burden of determining how to convey the information. A more specific approach to labels could improve the communication aspects of them, as well as making it easier for employers to comply.

National Advisory Committee on Occupational Safety and Health (NACOSH) Review of Hazard Communication

In a continuing effort to improve its Hazard Communication Program, OSHA asked NACOSH in September 1995 to convene an expanded working group to identify ways to improve chemical hazard communication and the "right-to-know" in the workplace. OSHA asked the committee to provide OSHA with recommendations to simplify material safety data sheets (MSDSs), reduce the amount of required paperwork, improve the effectiveness of worker training, and revise enforcement policies so that they focus on the most serious hazards.

The workgroup consisted of four members of NACOSH representing Management, Labor, Health and Public categories of membership, supplemented by ten additional members which included state regulators, the chemical industry, small and large business users, hazard communication consultants, unions, and an association which represents many small businesses. The workgroup held public hearings on October 19-20, 1995, with presentations made by small businesses and labor organizations, and on December 11-12, 1995, with presentations made by larger businesses, professional associations and others who requested to be heard. During a March 20-21, 1996 meeting, the workgroup heard presentations by specialists in training, electronic access systems, and the development of ANSI standards on MSDSs and labels.

According to the Executive Summary of the report, during the public presentations and workgroup discussions, there was general agreement on the following:

  • There is a need for hazard communication, and employees have a right-to-know about the hazardous chemicals in their workplace.

  • The Hazard Communication Standard (HCS) is a good one and the record should not be reopened at this time. However, consistency in interpretation should be stressed and enforcement should be more performance-oriented, emphasizing overall effectiveness.

  • MSDSs can become very long and complicated because they are used for many purposes other than to meet OSHA requirements.

  • Some, mainly small businesses, would like a two-page MSDS that is easy to understand, but not many wanted an additional document which would be necessary to accomplish this.

  • A uniform format should be encouraged; most agreed that OSHA should endorse use of the ANSI Z400.1 format.

  • Small businesses need implementation aids such as model programs and guidelines for training, evaluation and hazard determination.

  • Harmonization should be encouraged at the international, national and internal OSHA levels.

As a result of public presentations and workgroup discussions, the workgroup determined that two of the major problems cited -- complexity of MSDSs and the large paperwork burden involved in management of the MSDSs -- were not really caused by or under the control of OSHA.

The majority of presenters expressed a clear preference for a standardized format for MSDSs and supported use of the ANSI format. However, it was suggested that rather than open the record to mandate its usage, OSHA should "endorse" its use. OSHA has addressed this in its compliance directive on the rule. Most of the other recommendations made by NACOSH have also been implemented by OSHA.

Development of the Globally Harmonized System of Classification and Labeling of Chemicals (GHS)

The GHS has been mentioned several times as a long-term project that OSHA has been participating in. OSHA is not the only regulatory agency, and the US is not the only country, that has implemented an approach to disseminate information on chemicals to precipitate changes in handling methods. Since the US is both a major importer and exporter of chemicals, the manner in which other countries choose to regulate has an impact on the protection of workers in the US as well as on possible barriers to international trade in chemicals, and vice versa.

To protect workers and members of the public who are potentially exposed to chemicals during their production, transportation, use, and disposal, a number of countries have developed laws that require information about those chemicals to be prepared and transmitted to affected parties. These laws vary with regard to the scope of substances covered, definitions of hazards, the specificity of requirements (e.g., specification of a format for MSDSs), and the use of symbols and pictograms. The inconsistencies between the various laws are substantial enough that different labels and safety data sheets must often be used for the same product when it is marketed in different nations. For example, Canada has established requirements for labels under its Workplace Hazardous Materials Information System (WHMIS). WHMIS requires that labels include specified symbols within a defined circle. US chemical manufacturers must label chemicals accordingly for marketing in Canada.

Within the US, several regulatory authorities exercise jurisdiction over chemical hazard communication. In addition to OSHA's HCS, the Department of Transportation regulates chemicals in transport, the Consumer Product Safety Commission regulates consumer products, and EPA regulates pesticides. Each of these regulatory authorities operates under different statutory mandates, and as a result has adopted different approaches to hazard communication requirements.

The diverse and sometimes conflicting national and international requirements can create confusion among those who seek to use hazard information. Labels and safety data sheets may include symbols and hazard statements that are unfamiliar to readers or not well understood. Containers may be labeled with such a large volume of information that important statements are not easily recognized. Development of multiple sets of labels and safety data sheets is a major compliance burden for chemical manufacturers, distributors, and transporters involved in international trade. Small businesses may have particular difficulty in coping with the complexities and costs involved.

When the HCS was first issued in 1983, the preamble included a commitment by OSHA to pursue international harmonization of hazard communication requirements. This was requested to be included when the final rule went through executive branch review. Thus OSHA was the only Federal agency that had a public commitment to pursue harmonization, and we actively participated in a number of such efforts. The Agency issued an RFI in the Federal Register in January, 1990, to obtain input regarding international harmonization efforts, and on work being conducted by the International Labor Organization pertaining to chemical safety programs (55 FR 2166). In June of 1992, a mandate from the United Nations Conference on Environment and Development called for development of a globally harmonized chemical classification and labeling system. OSHA chaired the international coordinating group that managed the harmonization work, as well as being responsible for leading the US delegations on work involving the classification of mixtures and hazard communication. Representatives of labor and industry were also involved in the GHS development process. The product resulting from this effort, the Globally Harmonized System of Classification and Labeling of Chemicals (GHS), was formally adopted by the United Nations in December of 2002 (27). The GHS is now available for worldwide implementation, and countries have been encouraged to implement the GHS as soon as possible, with the goal of a fully operational system by 2008.

The GHS addresses a number of the issues discussed in this review. It establishes standardized criteria for determining the health, environmental, and physical hazards associated with chemicals. In addition, the GHS includes standardized requirements for labels and safety data sheets. GHS establishes standardized and more detailed requirements for labels, including consistent use of pictograms (e.g., skull and crossbones), signal words (e.g., Danger), and harmonized hazard statements (e.g., Fatal if Swallowed). Under this approach, employers would know exactly how to convey the hazards of th

e chemical once they complete the hazard classification. The harmonized label elements are provided for each hazard category and class within that category.

In addition, a standardized 16-section format is established for safety data sheets to provide a consistent sequence for presentation of information. With the exception of the order of two headings being reversed, the harmonized data sheets are the same as the ANSI standard. Items of common interest to workers are presented at the front of the document, while more technical information is presented later. Headings for the sections (e.g., First Aid Measures, Handling and Storage) are standardized to facilitate locating information of interest. Thus, with the exception of differences in language, only one label and one data sheet would be necessary for national and international commerce for any given product.

The GHS is intended to accomplish a number of objectives. A major goal is to improve the quality and consistency of chemical hazard information. It is also anticipated that the GHS, if implemented, will facilitate international trade in chemicals, reduce the need for chemical testing and evaluation, and provide a recognized framework for those countries without an existing hazard communication system.

The GHS clearly addresses a number of the issues raised regarding the current HCS requirements. If adopted by OSHA, it would result in more specific labels that would convey information consistently. The MSDSs would be in a standardized format, with the information workers and emergency responders need most appearing in the beginning of the document for easy reference. The standardized approach to labels and MSDSs would make it easier for employers to comply, particularly small employers, and would improve the communication aspects of the rule. Adoption of the GHS in the future may be a long-term solution to a number of existing issues.

The US is still in the process of determining whether to adopt the GHS. It is not a unilateral determination by OSHA. The most benefits will accrue if all of the affected agencies (OSHA, EPA, DOT, and CPSC) adopt the new system, which would thus result in domestic harmonization as well as international harmonization of chemical classification and labeling requirements.

What Can Be Done to Address Hazard Communication Issues

As has been discussed, issues regarding effective hazard communication have been considered by OSHA and others for a number of years. The key issue in terms of accuracy is that the quality of MSDSs and labels produced by chemical manufacturers and importers needs to be improved. Our approach, as outlined below, addresses this issue in two ways. First, OSHA is providing additional guidance and compliance assistance to such employers to help them develop better and more accurate materials. Secondly, OSHA is emphasizing the importance of accurate MSDSs in its enforcement of the HCS.

OSHA has published a number of guidance documents to assist the regulated community in complying with the HCS. Following publication of the 1983 final rule, OSHA prepared a booklet that provides a simple summary of the requirements of the HCS (28). This booklet has been updated periodically to reflect changes to the rule, and to indicate sources of additional information. It has also been translated into Spanish (29). In 1988, OSHA added a non-mandatory appendix (Appendix E) to the HCS that provides employer guidance for compliance. This appendix was subsequently published as a separate booklet (30). The employer guidance for compliance has also been published in Spanish (31). Each of these booklets is available from OSHA's Publications Office. The Agency has also prepared a compliance kit to assist employers (32). The kit is a step-by-step guide, and includes other information, such as a glossary of terms used on MSDSs. The kit is available through the Government Printing Office.

OSHA has a technical link page on our web page that is devoted to hazard communication issues. The webpage provides easy access to guidance materials, answers to frequently asked questions, and sources of additional information.

OSHA believes further efforts are necessary to enhance the quality of hazard information provided to employers and employees. The Agency is launching a hazard communication initiative to address this need and consolidate our efforts to improve hazard communication. The initiative includes additional, substantive guidance materials; an alliance with the key professional society in this field; an enforcement initiative; and the establishment of a portal page on our web site to consolidate materials available on hazard communication.


Three guidance documents that are designed to improve aspects of chemical hazard communication, including the development of complete, accurate, comprehensible MSDSs, are being developed. These documents are:

Guidance for Hazard Determination

The HCS requires that manufacturers and importers of chemicals evaluate available scientific evidence in order to identify physical or health hazards associated with any chemical they manufacture or import. This process is referred to as hazard determination. The hazard determination provides the basis for the hazard information that is provided in MSDSs, on labels, and during worker training. The intent of this document is to provide guidance on the process involved, and to identify considerations to be taken into account in the conduct of hazard determinations. Following this guidance should help preparers of MSDSs and labels ensure that the information they provide is complete and accurate. Comments on the draft guidance document are being solicited through OSHA's web page. A final document will be prepared after review of those comments.

Model Training Program for Hazard Communication

Employers are required by the HCS to provide training to employees who are exposed to hazardous chemicals. Training is needed to explain and reinforce the information presented on labels and MSDSs. This document is designed to assist employers in developing a training program that is tailored to the needs of their workplace, regardless of size or complexity. It provides extensive training materials so the employer may choose those appropriate to the workplace situation. Comments on the draft model training program are being solicited through OSHA's web page. A final document will be prepared after review of those comments.

Guidance for Preparation of MSDSs

MSDSs are intended to furnish detailed information regarding chemical hazards, as well as protective measures that are available. This document will provide guidance on how to write MSDSs that are clear, consistent, and complete. It will include a sample MSDS format, as well as instructions for composing individual sections of the MSDS. Sources that can be consulted to obtain information to complete the sections will be provided, as well as guidance on what type of information to include in each section. Suggestions for ensuring that the information is presented in a comprehensible manner will also be included. This document should help to address both the accuracy and the comprehensibility of MSDSs. It will be made available in draft form on our web page after the comment period on the first two documents is complete.


OSHA signed an Alliance with the Society for Chemical Hazard Communication (SCHC) on October 22, 2003 (33). SCHC is a professional society organized to promote the improvement of chemical hazard communication, and includes over 600 members representing a wide range of industries, academia, and government.

OSHA and SCHC are developing a work plan to implement the alliance. There are 3 items of particular relevance to this review. First, SCHC will work with OSHA to develop a short course on the preparation of MSDSs. Using their expertise in this area, as well as their experience in providing professional development courses for their members, the course will be designed for small business preparers of MSDSs. OSHA will use its existing programs to make the course available to be presented in various regions of the country. In addition, SCHC will work with OSHA to produce a checklist to be used to review MSDSs that will be available for both OSHA staff and the public on our website. This information, in combination with the guidance for preparation of MSDSs, will be used to prepare a training program for OSHA's compliance staff regarding review of MSDSs for accuracy. The program will be available to be presented in OSHA Area Offices.

We expect to develop other plans with SCHC as the Alliance develops, and consider this agreement to be a key feature of our initiative.


The HCS remains a focus of OSHA enforcement efforts. In fiscal year 2003, over 7,000 citations were issued by the Agency for violations of the HCS, making it the second most frequently cited OSHA standard. Over $1.3 million in penalties were assessed.

While HCS provisions are often cited, the accuracy of information is not the focus of these citations in most situations. In addition to the training described above, and the development of a review tool such as a checklist, OSHA is developing an enforcement initiative for compliance officers to review and evaluate the adequacy of MSDSs. Under this program, the Agency will choose a certain number of chemicals, and following the requirements in the HCS, identify some critical elements (phrases, words, etc.) that should appear on an accurate MSDS. Compliance officers would use this information as they encounter these chemicals at worksites. Where MSDSs are found that do not contain these critical elements, OSHA will notify the manufacturer in writing of the deficiencies or inaccuracies. Manufacturers will be required to correct and update their MSDS. They will then have to respond to OSHA and inform the Agency of the steps taken to correct and update their data sheet. Those manufacturers that fail to respond or do not update their MSDS can potentially be cited under the HCS.

In addition, compliance staff and the public are being made aware of the availability of International Chemical Safety Cards on OSHA's web page. These cards are similar to MSDSs in terms of the information provided. They are internationally developed and peer reviewed, cover over 1300 substances, and are available in 14 languages. They are a good screening tool to be used when reviewing MSDSs on the substances they cover, and are going to be modified to be consistent with the GHS classification criteria and MSDS format.

Portal Page on Hazard Communication

OSHA has considerable information available on its web page regarding hazard communication. With the launch of this initiative, the Agency is establishing a portal page to consolidate the information that can be accessed by a button on its home page. This will allow the public to easily find all of the guidance and compliance assistance materials, as well as the standard itself and many other sources of information that may be helpful to employers and employees.

Consideration of Revisions to the HCS

OSHA believes that the GHS provides a possible avenue for improving chemical hazard communication in the long term. Standardized presentation of information on labels and safety data sheets has the potential to address many of the concerns that have been raised regarding the comprehensibility of chemical hazard information. Standardization may also increase the accuracy of chemical hazard information. With consistent presentation of information, the task of reviewing safety data sheets and labels to assure accuracy would be simplified. Individuals preparing and reviewing these documents should find it easier to identify any missing elements, and OSHA enforcement personnel should be able to more efficiently examine safety data sheets and labels when conducting inspections. Any possible revisions of the HCS must be considered carefully. Such modifications would affect millions of employers and employees, involve other government agencies, and would require international coordination in order to maximize benefits. As a first step in this process, OSHA has compared the GHS requirements with the current requirements of the HCS in order to determine what changes would be involved if current regulatory requirements for chemical hazard communication are revised to conform to the GHS (34). OSHA is also developing a guide describing the GHS in simplified terms, and plans to make this document available in the near future. OSHA participates in an interagency committee on harmonization, and is working with other agencies potentially affected by the GHS. The other affected agencies are the Environmental Protection Agency (EPA), the Department of Transportation (DOT), and the Consumer Product Safety Commission (CPSC). The Agency's Alliance with SCHC is also anticipated to serve as a mechanism for increasing awareness of the GHS, and training sessions, forums, roundtable discussions, and stakeholder meetings are expected to address GHS issues. OSHA anticipates that these efforts will allow for informed stakeholder participation as the Agency determines an appropriate course of action regarding the GHS.


The HCS is an important tool in OSHA's efforts to ensure chemical safety in the workplace. In its 20 years of existence, it has greatly increased the amount of information available on chemicals. There are, however, certain concerns about accuracy and comprehensibility that need to be addressed. OSHA is launching an initiative of guidance, compliance assistance, work with an alliance partner, enforcement, and improved web access to information to address these concerns and further refine implementation of the HCS requirements. In addition, there are long-term opportunities to both globally harmonize the US approach and address concerns raised through implementation of the GHS.

Appendix re: Studies/Investigations re: Hazard Communication

There have been a number of studies and investigations over the years regarding different aspects of hazard communication. The following describes some of this information OSHA has reviewed:

OSHA commissioned an initial examination of the accuracy of MSDSs shortly after the scope of the rule was expanded to cover all industries (2). The report analyzed the content of 196 MSDSs for products used in auto repair and body shops. Although the analysis performed does not allow definitive conclusions to be drawn, the report provides a general indication of inconsistencies in the content and presentation of MSDSs.

In 1991, OSHA commissioned two additional studies relating to the quality of information provided on MSDSs (3, 4). The first study examined the accuracy of MSDSs (i.e., the correctness and completeness of the information provided). The second study evaluated the comprehensibility of MSDSs by workers (i.e., the ability of workers to understand the information presented). Although these studies were limited in scope, they provide a general indication of the quality of MSDSs in circulation at that time.

The study pertaining to the accuracy of MSDSs examined information presented in five areas considered crucial to the health of workers potentially exposed to hazardous substances. These five areas assessed were chemical identification of ingredients; reported health effects of ingredients; recommended first aid procedures; use of personal protective equipment; and exposure level regulations and guidelines. The evaluation was performed jointly by a board certified occupational physician and a toxicologist who was also a certified industrial hygienist. A total of 150 MSDSs were evaluated.

Based on the chemical ingredients identified, the accuracy in the other four areas of concern was evaluated based on information obtained from readily available reference sources. The evaluation indicated that 37% of the MSDSs examined accurately identified health effects data, 76% provided complete and correct first aid procedures, 47% accurately identified proper personal protective equipment, and 47% correctly noted all relevant occupational exposure limits. Only 11% of the MSDSs were accurate in all four information areas, but more (51%) were judged accurate, or considered to include both accurate and partially accurate information, than were judged inaccurate (10%). The study also concluded that the more recent MSDSs examined (those prepared between 1988 and 1990) appeared to be more accurate than those prepared earlier.

The study addressing comprehensibility of MSDSs assessed the ability of workers to understand information regarding the route of entry of the substance, the type of health hazard present, appropriate protective measures, and sources of additional help. Each of the 91 participating workers was provided with and tested on four different MSDSs. The workers answered the test questions based on information supplied on each of the MSDSs.

The results of the tests indicated that workers on average understood about two-thirds of the health and safety information on the MSDSs. The best comprehension was associated with information providing straightforward procedures to follow (e.g., in furnishing first aid, dealing with a fire, or in using personal protective equipment) or descriptions of how a chemical substance can enter the body. Workers had greater difficulty understanding health information addressing different target organs, particularly when more technical language was used. Workers also reportedly had difficulty distinguishing acute from chronic effects based on information presented in the MSDSs.

A subset of the group (18 workers) was also tested on an International Chemical Safety Card (ICSC). ICSCs summarize essential health and safety information on chemicals for use at the "shop floor" level by workers and employers. The documents, developed by the International Programme on Chemical Safety, consist of a series of standard phrases, mainly summarizing health and safety information. The information is verified and peer reviewed by a group of international experts. While MSDSs may be technically complex, ICSCs are intended to present information in a more concise and simple manner. ICSCs have been developed in English for over 1300 chemicals, and are also available in 13 other languages.

The average comprehensibility test score for the ICSC was higher than for any of the MSDSs. The average ICSC test score ranged from 6% to 23% higher than the average test score on the four MSDSs evaluated. This finding was considered to suggest that an improved format for MSDSs may serve to increase user comprehension of the information presented.

OSHA also commissioned a study, completed in 1999, focusing specifically on the accuracy of first aid information provided on MSDSs (5). A total of 56 MSDSs for seven chemicals were examined. First aid information on the MSDSs was compared with information from established references. The researchers reported that nearly all of the MSDSs reviewed had at least minor inaccuracies. Some of the more common problems identified included:

  • Treatment for all routes of exposure is not always identified;
  • Treatment recommendations for varying degrees of exposure is generally not given;
  • Induction of vomiting is often contraindicated if a chemical is ingested, but is often suggested on MSDSs;
  • MSDSs often do not state if the effects of exposure are delayed; and
  • Emergency responder protections are seldom listed.

The researchers also surveyed four poison control centers to investigate the procedures used to determine appropriate first aid measures for workplace chemical accidents. The researchers reported that the poison control centers contacted generally rely on MSDSs only for information on hazardous ingredients, and often find this information to be incomplete. The poison control centers were said to believe that MSDSs do not typically provide high quality, consistent, and reliable first aid information.

Literature Addressing MSDS Quality

A substantial volume of scientific literature has developed relating to chemical hazard communication. To examine this information, OSHA contracted with researchers at the University of Maryland to review the literature on key elements of hazard communication programs. The report derived from this review, completed in 1997, provides an analysis of the literature relating to material safety data sheets, labels, and training (6). Several of the studies mentioned in the report, as well as studies identified in a literature search conducted by OSHA to identify more recent publications, directly address the quality of MSDSs. Among the findings were:

  • In a study that examined the ability of a group of 75 printing employees to understand MSDSs, investigators found that employees with 15 years of formal education scored 66.2% on a test designed to measure understanding of MSDS information (7).
  • In an examination of MSDSs for the reproductive and developmental toxicants lead and ethylene glycol ethers, researchers found that 421 of 678 MSDSs (62%) made no mention of effects on the reproductive system (8).
  • In a study evaluating the comprehensibility of MSDS at a large research laboratory, thirty-nine percent of the workers found MSDSs "difficult to understand". One third of the workers found the MSDS format to be confusing. The study also indicated that a third of the information provided on MSDSs was not understood. These results were obtained from a study population of literate, trained workers who spoke English as their first language (9).
  • An evaluation of a sample of MSDSs from 30 manufacturers of toluene diisocyanate (a chemical known to cause asthma) revealed that half reported asthma as a potential health effect. One MSDS made no mention of any respiratory effects, while others used language (e.g., allergic respiratory sensitization) that the authors believed may not clearly communicate that asthma is a risk (10). It should be noted that OSHA would consider such language to be consistent with the requirements of the HCS.
EPA/OSHA Investigations

Under a memorandum of understanding between the Environmental Protection Agency (EPA) and OSHA, the two organizations conducted a number of joint investigations of chemical accidents (11). The reports of two of these inquiries mention MSDSs in relation to the incident being investigated:

Napp Technologies, Lodi, New Jersey

Water was apparently inadvertently introduced into a blending operation involving water-reactive chemicals. The resulting decomposition reaction was self-sustaining, and an emergency operation to unload the contents of the blender led to a deflagration that destroyed the facility and killed five workers.

The only information used to determine emergency response procedures was provided on the MSDSs. However, the MSDSs for the chemicals being combined in the blender gave contradictory information regarding firefighting measures. The MSDS for one chemical indicated that copious amounts of water should be used, while the MSDS for another component clearly stated that water should not be used. The MSDS for the finished product recommended "A water spray . . . to extinguish fire." These findings highlight the limitations of MSDSs information with regard to emergency response planning, and indicate the need for thorough hazard analysis of chemical processes (12).

Bartlo Packaging, West Helena, Arkansas

The facility received bulk shipments of chemicals and repackaged them into smaller containers. Smoke was reported in a warehouse area. The investigation concluded that the most likely scenario involved a bulk package of a pesticide that was placed adjacent to a hot compressor discharge pipe, initiating a decomposition reaction. Firefighters responding to the scene reviewed the MSDS for the product. The MSDS did not include information on decomposition temperatures or explosion hazards. When four firefighters approached the building to investigate, an explosive chemical reaction killed three and seriously injured the fourth (13).

In response to the Napp Technologies incident, OSHA issued a Hazard Information Bulletin (HIB) in July, 1996 (14). The HIB was intended to alert employers that rely on MSDSs created by other entities. OSHA warned that MSDSs for raw materials may not identify all hazards which may be encountered when mixing or blending them with other materials.

In 1999, EPA issued a Chemical Safety Alert to advise parties involved in emergency response activities that MSDSs alone may not provide sufficient information to effectively and safely respond to emergency situations, citing the findings of the two investigations (15). EPA also compared the information provided on four different MSDSs for an insecticide (azinphos methyl) and information from a database developed by the National Oceanic and Atmospheric Administration and EPA. Substantial differences were apparent in information presented regarding hazard ratings, reactivity information, incompatibilities, and fire hazards. EPA recommended that multiple data sources be consulted in order to ensure that responders take appropriate precautions.

OSHA issued a second HIB relating to MSDSs when a researcher suffered a fatal exposure to dimethylmercury in a university laboratory (16). The researcher was wearing latex rubber gloves, as recommended on the MSDS. One to several drops of dimethylmercury accidentally spilled on the back of her gloved left hand. The dimethylmercury penetrated the glove, resulting in the death of the researcher 10 months later. Subsequent permeation testing of the gloves by a certified, independent testing laboratory indicated that the chemical permeates latex almost instantaneously. In the HIB, OSHA warned that MSDSs may not provide adequate guidance on glove selection. There is no standard that requires employers to test gloves for their permeability.

CSB Investigations

Further concerns about the accuracy of MSDSs have been raised more recently based on reports issued by the Chemical Safety and Hazard Investigation Board (CSB). CSB is a federal agency whose principal function is to investigate chemical incidents to determine the circumstances that led up to the event, in order to identify the cause or causes so that similar events can be prevented. OSHA has examined reports of investigations completed by CSB through the end of 2003. A number of these reports mention deficiencies in hazard communication programs related to the incident subject to investigation. Although none of the CSB investigation reports specifically cited MSDS inaccuracy as a root or contributing cause of the incident in question, the reports identify a range of problems the CSB believed occurred in the hazard communication programs. Reports mentioning MSDSs include:

Morton International, Paterson, New Jersey

A runaway reaction during the production of Yellow 96 Dye caused an explosion that blew the hatch off of a 2000-gallon capacity chemical reactor vessel, releasing flammable material. The explosion and subsequent fires injured nine workers, two of whom were badly burned and required extended hospitalization.

Morton's MSDS for Yellow 96 Dye stated that the National Fire Protection Association (NFPA) reactivity hazard rating for this material was 0 (indicating materials that are normally stable, even under fire conditions). CSB determined that the proper reactivity rating for Yellow 96 Dye is 1 (indicating that the material is normally stable, but can become unstable at elevated temperatures and pressures). The NFPA ratings are used as an indicator of the degree of hazard associated with a chemical, and incorrect information can result in errors in handling or emergency response procedures. In this incident, the difference reportedly did not affect the emergency response activities. The HCS does not require that labels or MSDSs include NFPA ratings; but some manufacturers and employers choose to include them. The Yellow 96 Dye MSDS also stated that the compound's boiling point was 100 degrees Celsius (°C). CSB determined that the correct boiling point is approximately 330°C. It is unclear what additional precautions, if any, would have been taken in this case if the proper reactivity rating had been indicated. While these inaccuracies reportedly did not contribute to the incident in question, they provide an indication that the process used to determine hazards associated with exposure to Yellow 96 Dye was inadequate (17).

Bethlehem Steel Corporation Burns Harbor Division, Chesterton, Indiana

During repair of a coke oven gas (COG) line, condensate was released. The COG condensate, which was expected to be nonflammable, ignited. Two workers were killed and four were injured, one seriously.

The majority of the workers interviewed by CSB did not consider COG to pose a fire risk, and flammability was not considered in job planning. The Bethlehem Steel MSDS for COG condensate did not mention flammability as a hazard. It was considered to be normally nonflammable. However, a sample of COG condensate taken by CSB from the facility after the incident was highly flammable, with a flash point of 29 degrees Fahrenheit ( o F). A liquid with a flash point of less than 100 o F is classified as flammable according to the HCS. CSB recommended that Bethlehem Steel revise the MSDS for COG condensate to highlight the potential flammability hazard, and ensure that employees and contractors are informed of the potential presence of flammable liquids when working with or opening COG condensate piping and equipment (18).

BP Amoco Polymers, Augusta, Georgia

During an attempt to start production of Amodel (a type of nylon), partially reacted waste material was diverted to a catch tank. The continuing decomposition of the material generated gases that pressurized the tank. Unaware of the pressurization, three workers attempted to remove a cover from the catch tank. After half of the 44 bolts had been removed, the pressure caused the remaining bolts to break and the cover to fly off. The workers were struck by the cover and the expelled plastic, and were killed. CSB found that hazard analyses of the Amodel process were inadequate and incomplete, and recommended that the MSDS for Amodel be revised to warn of the hazards of accumulating large masses of molten polymer (19).

Motiva Enterprises Delaware City Refinery, Delaware City, Delaware

A crew of maintenance contractors was repairing grating on a catwalk in a sulfuric acid (H 2 SO 4 ) tank farm when a spark from their work ignited flammable vapors in one of the storage tanks. The resulting explosion caused the tank to separate from its floor, releasing its contents. Other tanks in the tank farm also released their contents. Hydrocarbons in the vapor and spent acid fueled a fire that burned for approximately one-half hour. One contractor was killed and eight others were injured.

CSB found that the flammability classification for spent H 2 SO 4 in oil industry MSDSs varies widely. Several MSDSs from refiners indicate that spent H 2 SO 4 is a flammable liquid and warn that hydrocarbons in the acid may burn, and flammable hydrocarbon gases may accumulate in the headspaces of tanks, truck trailers, and railcars. However, the Motiva MSDS for spent H 2 SO 4 in effect at the time of the incident showed an NFPA flammability rating of 0 (indicating that the substance is not combustible). The MSDS further stated in regard to firefighting measures that the product is not combustible. The contract employees who had been working on the catwalk repair job were unaware of the potential flammability of the material in the tanks (20).

First Chemical Corporation, Pascagoula, Mississippi

Steam leaked through manual valves, heating mononitrotoluene (MNT) inside a 135-foot-tall distillation column and causing a runaway reaction. The resulting explosion propelled debris both onsite and offsite (including one piece weighing over six tons that landed in an adjacent facility near crude oil storage tanks), and caused numerous fires. CSB determined that, due to an inadequate evaluation of hazards, MSDSs did not provide sufficient warning of the potential thermal instability of MNT. Training of operations personnel also did not include information on the hazards of leaving MNT at elevated temperatures for an extended period of time (21).

Other investigation reports reveal deficiencies in other aspects of hazard communication, including improper hazard determination, inadequate training, and the complete absence of a hazard communication program. Reports mentioning problems with aspects of hazard communication other than MSDSs include:

Sierra Chemical Company, Mustang, Nevada

Two explosions at a facility that manufactured explosive boosters for the mining industry killed four workers and injured six others. The scenario considered by CSB as most probable involved a worker who left an explosive chemical mixture in a mixing pot overnight. The mix solidified, and when the worker returned the next morning and started the motor of the mixing pot, the pot's blades caused the solidified mass to detonate. Debris then struck another building, causing the second explosion.

CSB determined the cause of the incident to be inadequate training for facility personnel. Worker training was conducted primarily in an ineffective, informal manner that over-relied on the use of on-the-job training. The information provided during training was at the discretion of the trainer. There were no written procedures, checklists, standards, or performance criteria. Workers engaged in unsafe practices, and did not recognize the hazards presented by these practices. After the explosion, some workers interviewed by CSB indicated they had not recognized the potential for such a serious incident (22).

Georgia-Pacific Naheola Mill, Pennington, Alabama

Sulfuric acid was added to a sewer to control pH downstream. Sodium hydrosulfide released at a tank truck unloading station drained to the sewer and reacted with the sulfuric acid to form hydrogen sulfide (H 2 S) gas. The gas cloud killed two contractors working on a construction project at the mill, and seven other construction contractors along with a truck driver were injured. CSB found that the manufacturer's MSDS for sodium hydrosulfide indicated that this substance will generate H 2 S gas if it contacts acid. The MSDS also recommended that runoff from large spills be prevented from entering sewers or drains. However, the company did not require detailed H 2 S safety training for workers in this area of the mill. CSB determined that the contractors did not have adequate training to understand the hazards of H 2 S (23).

BLSR Operating, Rosharon, Texas

During the unloading of gas condensate storage tank basic sediment and water (BS&W) from two vacuum trucks, hydrocarbon vapor was released. The vapor cloud ignited (likely from the vacuum truck engines), resulting in a deflagration and fire. Three workers were killed, and four were seriously burned. CSB found that the potential flammability hazard of BS&W was not properly identified, and employees and contractors were not informed of the hazard. The required MSDS was not provided to the vacuum truck drivers, and condensate storage tanks were not labeled with hazard information (24).

Environmental Enterprises, Cincinnati, Ohio

A maintenance employee entered a wastewater treatment room to retrieve a tool. He was overcome by H 2 S gas and collapsed. CSB investigators determined that this incident occurred because wastes were chemically treated in a vessel not designed for such use. Among the factors reportedly contributing to the incident was inadequate communication regarding the hazards of H 2 S (25).

Kaltech Industries Group, New York, New York

Kaltech employees combined hazardous waste from smaller containers into two larger drums. The wastes were incompatible, and an explosion occurred. The explosion and subsequent fire injured 36 people, including six firefighters and 14 members of the public, and extensively damaged a 10-story mixed-occupancy building. CSB found that Kaltech had not developed or maintained a chemical hazard communication program in accordance with the HCS. No list of hazardous chemicals had been compiled, containers of wastes and certain chemicals onsite were not labeled, employees received no formal training on chemical hazards, and MSDSs were not made available to workers (26).

GAO Studies on Hazard Communication

In November 1991 the General Accounting Office (GAO) issued a report based on its evaluation of certain aspects of the HCS (35). GAO examined compliance with the HCS, particularly among small employers; the adequacy of OSHA's efforts to inform small employers of their obligations under HCS; and the adequacy of OSHA's strategy for overseeing the accuracy and clarity of information on MSDSs. As part of its review process, GAO conducted a national survey of construction, manufacturing, and personal services providers. A total of 1,120 responses were received from employers. GAO also reviewed OSHA inspection data as well as policies and procedures in place for ensuring the quality of MSDSs.

GAO found that a substantial number of employers were not in compliance with the HCS. Twenty-six percent of worksites inspected by OSHA were reported to be in violation of at least one provision of the HCS. The report correctly noted, however, that OSHA inspections do not represent a random sample of worksites. OSHA focuses its inspection efforts on worksites where incidents involving fatalities or multiple hospitalizations have occurred, where complaints have been received, and on high-hazard industries. It is not unreasonable to believe that such worksites are more likely to be out of compliance with the HCS than worksites in general. Inspection data examined by GAO was from fiscal years 1989 and 1990, and may not be representative of current knowledge of and compliance with the HCS.

The random sample of employers surveyed by GAO indicated an even higher rate of non-compliance. According to this survey, 52% of all employers were not in compliance with the HCS. Non-compliance was said to be higher among small employers than among large employers, and many small employers indicated that they had little or no awareness of the HCS.

Several recommendations were included in the GAO report. GAO proposed that MSDSs include a brief description of employer responsibilities under the HCS. OSHA has not pursued this recommendation because it is not clear that such a description would lead to improved compliance with the HCS. Such a change would also require OSHA rulemaking, a time-consuming and resource-intensive process, and would involve a substantial burden on those who would be required to revise MSDSs. OSHA has pursued another of the GAO recommendations, to clearly specify the language and presentation of information on MSDSs. As discussed in this review, OSHA has endorsed the ANSI standard MSDS format, and has worked towards development of the standardized requirements in the GHS.

GAO also recommended that OSHA develop a more effective strategy for ensuring that manufacturers and importers correctly evaluate chemical hazards by targeting those who consistently prepare erroneous MSDSs, and establishing an inspection program to review hazard evaluations. However, as a practical matter OSHA is not able to review the hazard determination process itself, but only the results of that process - the information presented on MSDSs and labels. Because of the large number of chemicals in use and the resources needed to evaluate the content of an MSDS, it is extremely difficult for the Agency to compile sufficient data to indicate that a particular party consistently prepares erroneous MSDSs.

Following up on this initial report, GAO issued a second report in May 1992 presenting the findings of an examination of difficulties small employers were said to experience in complying with the HCS, as well as issues relating to the costs of compliance (36). The findings were based on the results of the employer survey mentioned previously. GAO found that over 56% of employers reported "great" or "very great" improvement in the availability of hazard information in the workplace and in management's awareness of workplace hazards. Forty-five percent of those in compliance with the HCS considered the standard to have a positive effect on employees, compared with only 9% who viewed the effect as negative. Almost 30% of employers reported that they had replaced a hazardous chemical with a less hazardous substitute because of information presented on an MSDS.

Almost 70% of small employers complying with the HCS reported no difficulty in maintaining MSDSs and providing access to employees. Larger employers reported comparatively more difficulty, likely due to a need to manage a larger quantity of MSDSs and provide access to a greater number of employees (half of all large employers reported that they had 250 or more MSDSs). With regard to training, almost 80% of small employers complying with the HCS reported some difficulty. Insufficient training expertise and complex MSDSs were cited as particular problems.

The GAO findings appear to indicate that non-compliance with the HCS is largely due to lack of knowledge about the requirements of the standard, rather than difficulty in complying with the provisions of the standard. These results point toward greater outreach and compliance assistance efforts as a way to improve compliance. The results also indicate that when employers comply with the provisions of the standard, the result is generally recognized as beneficial to workers.


(1) The NACOSH Haz Com Workgroup. 1996. National Advisory Committee on Occupational Safety and Health, Report to OSHA on Hazard Communication.

(2) Karstadt, M. 1988. Final Report. Report prepared for OSHA under contract 816605. Docket H022D, Ex. 4-203.

(3) Kearney/Centaur. 1991. The Accuracy of Material Safety Data Sheets. Report prepared for OSHA under contract J-9-F-8-0019. The results of this study were later published as: Kolp, PW; Williams, PL; and Burtan, RC. 1995. Assessment of the Accuracy of Material Safety Data Sheets. Am Ind Hyg Assoc J 56:178-183.

(4) Kearney/Centaur. 1991. The Comprehensibility of Material Safety Data Sheets. Report prepared for OSHA under contract J-9-F-8-0019. The results of this study were later published as: Kolp, P; Sattler, B; Blayney, M; and Sherwood, T. 1993. Comprehensibility of Material Safety Data Sheets. Am J Ind Med 23:135-141.

(5) The Lexington Group. 1999. Summary Report on the Evaluation of the Accuracy of First Aid Information on Material Safety Data Sheets. Report prepared under contract to OSHA Directorate of Technical Support.

(6) Sattler, B; Lippy, B; and Jordan, TG. 1997. Hazard Communication: A Review of the Science Underpinning the Art of Communication for Health and Safety.

(7) Printing Industries of America, Inc. 1990. Comments of the Printing Industries of America on the OSHA Hazard Communication Standard. Docket H-022G Ex. 2-313.

(8) Paul M, Kurtz S. 1994. Analysis of Reproductive Health Hazard Information on Material Safety Data Sheets for Lead and the Ethylene Glycol Ethers. Am J Ind Med. 25(3):403-15.

(9) Phillips, CC. 1997. The Efficacy of Material Safety Data Sheets and Worker Acceptability. Dissertation presented for the Doctor of Philosophy Degree at the University of Tennessee at Knoxville, (May). As cited in: Sattler, B; Lippy, B; and Jordan, TG. 1997. Hazard Communication: A Review of the Science Underpinning the Art of Communication for Health and Safety.

(10) Frazier LM, Beasley BW, Sharma GK, and Mohyuddin AA. 2001. Health Information in Material Safety Data Sheets for a Chemical that Causes Asthma. J Gen Intern Med. 16(2):89-93.

(11) Memorandum of Understanding between the United States Environmental Protection Agency, Office of Solid Waste and Emergency Response, Office of Enforcement and Compliance Assurance, and the United States Department of Labor, Occupational Safety and Health Administration on Chemical Accident Investigation. 1996.

(12) EPA and OSHA. 1997. EPA/OSHA Joint Chemical Accident Investigation Report, Napp Technologies, Inc., Lodi, New Jersey. EPA 550-R-97-002.

(13) EPA and OSHA. 1999. EPA/OSHA Joint Chemical Accident Investigation Report, BPS, Inc., West Helena, Arkansas. EPA 550-R-99-003.

(14) OSHA. 1996. Hazard Information Bulletin: Water-Reactive Chemicals, Hazardous Materials Not Covered Under 29 CFR 1910.119.

(15) EPA Office of Solid Waste and Emergency Response. 1999. Chemical Safety Alert, Use Multiple Data Sources for Safer Emergency Response. EPA EPA-F-99-006.

(16) OSHA. 1998. Hazard Information Bulletin for: Dimethylmercury.

(17) U.S. Chemical Safety and Hazard Investigation Board. 2000. Investigation Report, Chemical Manufacturing Incident, Morton International, Inc., Paterson, NJ. Report No. 1998-06-I-NJ.

(18) U.S. Chemical Safety and Hazard Investigation Board. 2002. Investigation Report, Steel Manufacturing Incident, Bethlehem Steel Corporation, Burns Harbor Division, Chesterton, Indiana. Report No. 2001-02-I-IN.

(19) U.S. Chemical Safety and Hazard Investigation Board. 2002. Investigation Report, Thermal Decomposition Incident, BP Amoco Polymers, Inc., Augusta, Georgia. Report No. 2001-03-I-GA.

(20) U.S. Chemical Safety and Hazard Investigation Board. 2002. Investigation Report, Refinery Incident, Motiva Enterprises LLC, Delaware City Refinery, Delaware City, Delaware. Report No. 2001-05-I-DE.

(21) U.S. Chemical Safety and Hazard Investigation Board. 2003. Investigation Report, Explosion and Fire, First Chemical Corp., Pascagoula, Mississippi. Report No. 2003-01-I-MS.

(22) U.S. Chemical Safety and Hazard Investigation Board. 1998. Investigation Report, Explosives Manufacturing Incident, Sierra Chemical Company, Mustang, Nevada. Report. No. 98-001-I-NV.

(23) U.S. Chemical Safety and Hazard Investigation Board. 2002. Investigation Report, Hydrogen Sulfide Poisoning, Georgia-Pacific Naheola Mill, Pennington, Alabama. Report. No. 2002-01-I-AL.GP_Report.

(24) U.S. Chemical Safety and Hazard Investigation Board. 2003. Investigation Report, Vapor Cloud Deflagration and Fire, BLSR Operating, Ltd., Rosharon, Texas. Report No. 2003-06-I-TX.

(25) U.S. Chemical Safety and Hazard Investigation Board. 2003. Case Study, Hydrogen Sulfide Exposure, Environmental Enterprises, Inc., Cincinnati, Ohio. NO. 2003-02-C-OH.

(26) U.S. Chemical Safety and Hazard Investigation Board. 2003. Investigation Report, Chemical Waste-Mixing Incident, Kaltech Industries Group, Inc., Borough of Manhattan, New York, New York. Report No. 2002-02-I-NY.

(27) Globally Harmonized System of Classification and Labeling of Chemicals. 2003. United Nations, New York and Geneva. ST/SG/AC.10/30

(28) OSHA. 1998(Revised). Chemical Hazard Communication. OSHA 3084. Also available as a 284 KB PDF.

(29) OSHA. 1989(Revised). Informacion Sobre Los Riesgos de Los Productos Quimicos OSHA 3117.

(30) OSHA. 2000(Revised). Hazard Communication Guidelines for Compliance. OSHA 3111.

(31) Informacion Sobre Riesgos Normas de Cumplimiento. 1989(Revised). OSHA 3116.

(32) Hazard Communication: A Compliance Kit. 1999. GPO S/N 029-016-00200-6.

(33) Agreement Establishing an Alliance Between the Occupational Safety and Health Administration U.S. Department of Labor and the Society for Chemical Hazard Communication. 2003.

(34) Sullivan, MR. 2003. GHS - OSHA HCS Comparison. Report prepared for OSHA under contract J-9-0-0051.

(35) General Accounting Office. 1991. OSHA Action Needed to Improve Compliance With Hazard Communication Standard. GAO/HRD-92-8.

(36) General Accounting Office. 1992. Employers' Experience in Complying With the Hazard Communication Standard. GAO/HRD-92-63BR.

Thank You for Visiting Our Website

You are exiting the Department of Labor's Web server.

The Department of Labor does not endorse, takes no responsibility for, and exercises no control over the linked organization or its views, or contents, nor does it vouch for the accuracy or accessibility of the information contained on the destination server. The Department of Labor also cannot authorize the use of copyrighted materials contained in linked Web sites. Users must request such authorization from the sponsor of the linked Web site. Thank you for visiting our site. Please click the button below to continue.