|DIRECTIVE NUMBER: CPL 2-2.70
||EFFECTIVE DATE: December 14, 2001|
|SUBJECT: Inspection Procedures for Occupational Exposure to Methylene Chloride Final Rule 29 CFR Part 1910.1052, 29 CFR Part 1915.1052 and 29 CFR Part 1926.1152.|
||This instruction ensures uniform enforcement of the Occupational Exposure to Methylene Chloride Standard as amended in the Federal Register (September 22, 1998, pages 50711-50732), by setting enforcement policy, providing inspection guidelines, and clarifying and interpreting the regulatory text.|
||Federal Register (FR), Vol. 62, No. 7, Jan 10, 1997, pp. 1493-1619; FR, Vol. 62, No. 249, Dec 18, 1997, pp. 66275-66277; FR, Vol. 63, No. 183, Sept 22, 1998, pp. 50711-50732; FR, Vol. 63, No. 5, Jan 8, 1998, pp.1152-1300. See paragraph III for additional references.|
||This Instruction cancels OSHA Instruction CPL 2-2.68, effective April 24, 1998 and Paula White's memorandum of January 21, 1998, "Methylene Chloride - Requests for Consultation Assistance.|
||This instruction describes a Federal Program Change for which State adoption is not required (see paragraph VII).|
||Regional and Area Offices and Office of the Solicitor (SOL)|
||Office of Health Compliance Assistance (OHCA)|
N3603, Frances Perkins Building
200 Constitution Avenue, NW
Washington, DC 20210
By and Under the Authority of
John L. Henshaw
This instruction revises CPL 2-2.68, issued April 24, 1998. This revision is necessary in order to bring the information and guidance provided into full agreement with the Occupational Exposure to Methylene Chloride Standard as amended in the Federal Register (September 22, 1998.)
- Provides a brief summary of the changes made to the standard by the amendment of September 22, 1998.
- Contains a table that deciphers the compliance dates set by the standard.
- Omits instructions for observing the restrictions on enforcement of the Methylene Chloride Standard provided by House/Senate Conference Report for the 1998 FY appropriations bill (H.R. 2264) for the Departments of Labor, Health and Human Services, and Education.
- Improves on the guidance to compliance safety and health officers (CSHOs) for conducting an inspection in the face of uncertain exposure to methylene chloride vapor.
- Includes, as Appendix B, a memorandum from the Cincinnati Technical Center that provides information on equipment available to CSHOs for tracking their methylene chloride exposures during an inspection of a work place.
Table of Contents
Table of Contents
- Action Information
- Responsible Office
- Action Offices
- Information Offices
- Federal Program Change
- General Considerations
- Inspection Guidelines for the Compliance Officer
- Collection of Information from the Employer
- Inspection of a Workplace Where the Employer Has Not Assessed the Methylene Chloride Exposure
- Remote sampling
- Additional Inspection Guidance
- Exposure Recording Guideline for the Area Offices
- Specific Provisions of 29 CFR 1910.1052
- Guidelines for Area Offices for Classifying and Grouping Violations
- Authorization to Review Limited Medical Information
- Required Training and Experience for Compliance Officers
- Guidelines for Regional Administrators and Area Directors for Providing Personal Protective Equipment (PPE)
Questions And Answers
Regulatory Text Information
Scope and Application
Methods of Compliance
Employee Information and Training
Methylene Chloride Exposure Tracking
- Reproduced Memorandum.
Evaluating the Methylene Chloride Hazards and the Effectiveness of the Protective Measures Used
Protective Clothing and Equipment Evaluation
Supplied Air Systems Evaluation
- Purpose. This instruction ensures uniform enforcement of the Occupational Exposure to Methylene Chloride Standard as amended in the Federal Register of September 22, 1998, pages 50711-50732, by setting enforcement policy, providing inspection guidelines, and clarifying and interpreting the regulatory text.
- Scope. This instruction applies OSHA-wide.
- Federal Register, Volume 62, Number 7, January 10, 1997, pages 1493-1619: Occupational Exposure to Methylene Chloride, Final Rule.
- OSHA Instruction, CPL 2.103, September 26, 1994, Field Inspection Reference Manual.
- OSHA Instruction, CPL 2-2.30, November 14, 1980, Authorization of Review of Medical Opinions.
- OSHA Instruction, CPL 2-2.32, January 19, 1981, Authorization of Review of Specific Medical Information.
- OSHA Instruction, CPL 2-2.33, February 8, 1982, Rules of Agency Practice and Procedure Concerning OSHA Access to Employee Medical Records-Procedures Governing Enforcement Activities.
- OSHA Instruction, CPL 2-2.46, January 5, 1989, Authorization and Procedures for Reviewing Medical Records.
- OSHA Instruction, CPL 2-2.54A, July 14, 2000, Respiratory Protection Program Guidelines.
- Federal Register, Volume 62, Number 249, December 18, 1997, pages 66275-66277, Methylene Chloride; Partial Stay.
- Federal Register, Volume 63, Number 5, January 8, 1998, pages 1152-1300: Respiratory Protection; Final Rule.
- Federal Register, Volume 63, Number 183, September 22, 1998, pages 50711-50732, Methylene Chloride; Final Rule.
- Cancellation. This instruction cancels OSHA Instruction CPL 2-2.68, Inspection Procedures for Occupational Exposure to Methylene Chloride Final Rule 29 CFR Part 1910.1052, 29 CFR 1915.1052, and 29 CFR 1926.1152, effective April 24, 1998.
- Action Information.
- Responsible Office. Office of Health Compliance Assistance.
- Action Offices. OSHA Regional and Area Offices, and SOL of U.S. Department of Labor.
- Information Offices. Office of Occupational Medicine, State Plan State Offices, and Consultation Project Offices.
- Action. OSHA Regional Administrators and Area Directors must use the guidelines in this instruction to ensure uniform enforcement of the Occupational Exposure to Methylene Chloride Standard, 29 CFR 1910.1052, 29 CFR 1915.1052, and 29 CFR 1926.1152
- Federal Program Change. This instruction describes a Federal Program Change for which State adoption is not required.
NOTE: In order to effectively enforce a new or revised standard, guidance to compliance staff is necessary. Therefore, although adoption of this instruction is not required, States are expected to have enforcement policies and procedures which are at least as effective as those of Federal OSHA.
- The final Occupational Exposure to Methylene Chloride Standards, 29 CFR 1910.1052, 29 CFR 1915.1052, and 29 CFR 1926.1152 supersede the regulations for employee exposure to methylene chloride (MC), also known as dichloromethane (DCM), that were contained in the OSHA air contaminant standards 29 CFR 1910.1000, 29 CFR 1915.1000, and 29 CFR 1926.55, for General Industry, Shipyards, and the Construction Industry, respectively. The final rule establishes permissible exposure limits (PELs) of 25 ppm (8-hour time weighted average -- TWA) and 125 ppm (15-minute short term exposure limit -- STEL). In addition, the standard provides for medical removal protection (MRP) benefits for employees and contains other provisions typical of those found in OSHA health standards promulgated under section (6)(b)(5) of the Act. Depending on exposure conditions at the workplace, these other provisions include requirements for:
- Monitoring the workers' exposures;
- Establishing regulated areas to reduce the number of workers potentially exposed;
- Implementing engineering and work practice controls to achieve the necessary reductions in exposure;
- Providing respiratory protection and protective clothing and equipment where necessary;
- Making hygiene facilities available where necessary;
- Making medical surveillance available;
- Communicating information about methylene chloride to workers and training them in its safe use; and
- Keeping records related to the standard.
- OSHA published the standard in the Federal Register on January 10, 1997 and made it effective on April 10, 1997. Later, on December 18, 1997, OSHA granted a partial administrative stay of the standard. The stay applied to employers of specified sizes in certain identified application groups, i.e., those that use methylene chloride in certain work operations. It delayed the startup dates by which these employers (1) must use respirators to protect employees exposed above the 8-hour TWA PEL and (2) must have instituted feasible engineering controls for achieving the STEL and the 8-hour TWA PEL. Then subsequently, on September 22, 1998, OSHA published in the Federal Register amendments to the standard. Among other changes, OSHA set new startup dates to replace the ones affected by the administrative stay. The table identified as Figure 1 provides the startup dates for all provisions of the standard for all employers.
- The amendments also:
- Modify the medical surveillance provisions to incorporate temporary medical removal protection (MRP). The temporary MRP is accorded employees who are removed or transferred to another job because of a medical determination that exposure to methylene chloride may aggravate or contribute to the employee's existing skin, heart, liver, or neurological disease. The compliance date for the new MRP provisions was October 22, 1998 for all employers.
- Require employers who have been granted a time extension for implementing engineering controls and respiratory protection in order to achieve the 8-hour TWA PEL, and who have done exposure monitoring indicating that the STEL is not exceeded, to nonetheless continue to monitor the STEL exposures at 3-month intervals until they have implemented such engineering controls and/or respiratory protection. The startup date for these employers to resume STEL exposure monitoring was October 22, 1998.
To see Figure 1 click here
Exposure Recording Guideline for the Area Offices. Prepare records of compliance officers' methylene chloride exposures obtained by self-monitoring and send them to the Office of Occupational Medicine in the National Office for retention.
- General Considerations. The final standards, 29 CFR 1910.1052, 29 CFR 1926.1152, and 29 CFR 1915.1052, apply to all occupational exposures to methylene chloride in general industry, the construction industry, and shipyard employment, respectively. Shipyards are entities engaged in shipbuilding, ship repair, or shipbreaking. The General Industry Standard, 29 CFR 1910.1052, applies to marine terminal and longshoring employment only insofar as affected employees are exposed to hazards that are not addressed by compliance with parts 1917 and 1918, respectively. OSHA will be finalizing standards for marine terminals and longshoring operations, setting forth the requirements applicable to chemical handling in the cargo handling environment. None of the standards applies to Agriculture Employment, which is covered under 29 CFR 1928.
- Inspection Guidelines for the Compliance Officer.
- Collection of Information from the Employer. During the opening conference, collect information that will be of assistance when conducting the inspection. Request the employer to provide:
- Required documents, e.g., medical surveillance records, training records, the respiratory protection program for all affected employees, and material safety data sheets (MSDSs) for products containing methylene chloride;
- A copy of any written program for improving or instituting engineering and work practice controls to limit employee exposure to methylene chloride; (Note: The standard does not require the employer to develop a written compliance program. However, whenever monitoring results indicate that employee exposure is above the STEL or the 8-hour TWA PEL, then in accordance with 29 CFR 1910.1052(d)(5)(ii), the employer must describe in the written employee notification of the monitoring results the corrective action being taken to reduce employee exposure to or below the STEL or 8-hour TWA PEL and the schedule for completion of this action.)
- Prior to the walk-around, copies of employee exposure monitoring data including data from a self-audit or consultation visit, objective data, and any other employee exposure assessment data that may be available. (Note: You will need these data to develop a strategy for inspecting the workplace and determining the level of protection required to safely conduct the inspection. If an employer possessing any of these data refuses to supply it, inform the Area Director as the use of compulsory process may be the correct response. The Area Director determines when to use compulsory process as discussed in the FIRM.)
- Inspection of a Workplace Where the Employer Has Not Assessed the Methylene Chloride Exposure.
- Some employers will neither have established regulated areas nor determined the airborne levels of methylene chloride in their workplaces. In this situation it may be very difficult to recognize by observation whether in a specific area the methylene chloride air concentrations are above or below the relevant PELs. If this is the case:
- Before conducting the inspection:
1. Search the OCIS Lab Report file for previous methylene chloride sample results for the establishment.
2. Review the OCIS OSHA Air Sampling History to identify methylene chloride air concentration levels for the establishment industry.
NOTE: The above paragraphs were deleted on August 2, 2005 and replaced by the language below to reference up-to-date resources and compliance guides. The symbol (***) marks the end of the added paragraphs.
- Search the LISA sample results data base for previous methylene chloride sample results which may have been collected for the establishment being inspected (if a previous OSHA inspection has taken place at this site). This data base would list individual sample results obtained during previous inspections conducted at the establishment. The LISA sample results data base may be accessed through the CSHO Home Page under the Reference Information section. Sample results may be accessed by conducting a search using the Area Office Reporting ID number or the individual inspection number.
- Review the IMIS data base to identify industries where methylene chloride over exposures have been cited during OSHA inspections.
- The following OSHA publications were developed after the promulgation of the Methylene Chloride final rule and are available to assist employers in a variety of industries with methylene chloride compliance issues. If the industry to be inspected is one of the following, the CSHO may want to refer to these documents prior to conducting the inspection. These publications will provide guidance on issues related to methylene chloride exposures and their control measures.
- At the preliminary stage of the inspection, screen the methylene chloride air concentration levels to aid in deciding the approach for proceeding with the inspection.
- The best approach for conducting an inspection in the face of an uncertain methylene chloride exposure hazard will have to be determined on a case-by-case basis. Some possible approaches are as follows:
- Keep close track of the air concentration levels with a direct reading instrument. Use this information to avoid methylene chloride exposures above the PELs and the need for respiratory protection during your conduct of the inspection. In some cases it might be a good idea to carry a gas mask with an organic vapor canister in the event you encounter an emergency escape situation. (Note: The use of air-purifying respirators for protection from methylene chloride concentrations above the PELs is not an option, except for a gas mask with an organic vapor canister in an emergency escape situation.) In some cases you may need to conduct remote sampling of employee exposures to methylene chloride in order to avoid overexposure.
- Keep close track of methylene chloride air concentration levels with a direct reading instrument and don a self-contained breathing apparatus (SCBA) when you need protection against methylene chloride concentrations above either PEL. WARNING: The use of an SCBA is stringently controlled. Refer to paragraph ix.d.3. in instruction cpl 2-2.54a, respiratory protection program guidelines, for the controls on using an SCBA. Staff from the Health Response Team may be available to conduct the inspection if no SCBAs or compliance officers qualified to use SCBAs are available in the Area Office or elsewhere in the Region.
- Upon deciding on an approach for conducting the inspection, review the approach with the Area Office and obtain its approval of the approach before proceeding with the inspection. (Note: The Area Office must consult the Assistant Regional Administrator for Technical Support (ARA/TS) for assistance in determining the appropriateness of SCBA use in a specific situation. Moreover, it must coordinate with the ARA/TS any planned entry involving the use of an SCBA.)
- When you need to monitor your methylene chloride exposure for your protection, keep a record of the time spent in various air concentrations of methylene chloride for calculating your 8-hour TWA and short term exposures. (Some guidance on selecting a monitoring device is contained in Appendix B.)
- Remote sampling.
- Remote sampling may be used to document violations if the problems associated with this approach will not be significant or can be resolved in the case at hand.
- In a case where you cannot find a location to observe the work processes or the employees at their work:
- Be on guard against events such as the following going unnoticed:
- Tampering with the sampling device such as turning the pump off or placing the sampler nearer or farther away from the point that would best indicate an employee's exposure.
- Pump failure or malfunction.
- An employee failing to return at the appropriate time for changing the sampling media.
- There may be complications in determining whether the employer has instituted all feasible work practices and engineering controls.
- If you can set up an employee with sampling equipment, place yourself far enough away from an operation to avoid overexposure, but close enough to observe the operation, then remote sampling may not present any problems. However, this would only be the case if you can watch the sampling process well enough to ensure the validity of the samples, and you can examine the work processes and equipment well enough to evaluate the work practices and engineering controls. In a situation where you want to get a closer look at the sampling device, work process, or plant equipment, it may be possible to approach them for a brief time and still avoid overexposure. If this is too risky, it might be possible for you to get a better look with binoculars, a zoom still camera, or a zoom video camera.
- Additional Inspection Guidance. Appendices A and C contain additional information you may find helpful in evaluating the employer's compliance with the Methylene Chloride Standard.
Specific Provisions of 29 CFR 1910.1052. Guidelines and clarifications relating to specific provisions of the standard are provided in Appendix A, Questions and Answers and Appendix D, Factors to Consider in Evaluating Methylene Chloride Control and Employee Exposure.
Guidelines for Area Offices for Classifying and Grouping Violations. In general, follow the procedures in the Field Inspection Reference Manual, Chapter III, paragraphs C.2. and C.5. If deviations appear appropriate, discuss and coordinate them with the Regional Office.
Authorization to Review Limited Medical Information. Appropriately qualified compliance personnel are authorized to review medical records and medical opinions pertinent to a review of compliance with the methylene chloride standard. This authorization has limitations and procedures you must follow as set forth in OSHA Instructions CPL 2-2.30, CPL 2-2.32, CPL 2-2.33, and CPL 2-2.46.
Required Training and Experience for Compliance Officers. As a compliance officer who conducts methylene chloride inspections, you are expected to know the following:
Guidelines for Regional Administrators and Area Directors for Providing Personal Protective Equipment (PPE). Ensure that appropriate PPE for methylene chloride is available for the compliance officers and used when required.
- The potential hazards which you may encounter at the site, including the potential hazards of methylene chloride.
- The contents of the Methylene Chloride standard, including the appendices.
- The contents of this instruction.
- The appropriate protective equipment you must wear. Each compliance officer who uses protective equipment must be trained in the proper care, use, and limitations of the equipment. Use of respiratory protection by compliance officers is covered in OSHA Instruction CPL 2-2.54A.
- The appropriate emergency procedures.
- Supplied-air respirators are required for inspections where the compliance officer will need respiratory protection. In the vast majority of cases, the only supplied-air respirator a compliance officer could wear while conducting an inspection is a self-contained breathing apparatus (SCBA). Refer to paragraph IX.D.3. in Instruction CPL 2-2.54A, Respiratory Protection Program Guidelines, for the controls on using an SCBA. Staff from the Health Response Team may be available to conduct the inspection if no SCBAs or compliance officers qualified to use SCBAs are available in the Area Office or elsewhere in the Region. If a situation exists where a respirator would only be needed for emergency escape, then a gas mask with an organic vapor canister is acceptable.
- For inspections in which the compliance officer could experience skin or eye exposure to liquid methylene chloride, provide clothing and eye protection that is resistant to methylene chloride.
Q. What are the adverse health effects associated with exposure to methylene chloride?
A. The effects include cancer, cardiac and central nervous system disturbances, and skin or eye irritation.
Q. Why does the standard contain a short-term exposure limit (STEL) of 125 ppm, measured over a 15-minute period?
A. The STEL protects employees from the acute toxicity of methylene chloride, the carcinogenic metabolites of methylene chloride, and complements the protection from methylene chloride's carcinogenic effects provided by compliance with the 8-hour time-weighted average (TWA) exposure limit of 25 ppm.
Q. How does the STEL protect employees from the carcinogenic metabolites of methylene chloride?
A. Metabolic evidence suggests that the mixed function oxidase system (MFO) pathway (the metabolic pathway not believed to be a major contributor to carcinogenesis) begins to be saturated at approximately 100 ppm and metabolism by the glutathione-S-transferase (GST) pathway (the putative carcinogenic pathway) becomes more important quantitatively at that level. Compliance with the STEL limits metabolism by the GST pathway and protects the employee from excessive exposure to potentially carcinogenic metabolites of methylene chloride.
Q. What are the acute toxic effects of methylene chloride?
A. Acute toxicity of methylene chloride is characterized by central nervous system (CNS) disturbances, such as decreased alertness and coordination, headaches, and dizziness, which may ultimately lead to accidents and further exposure to methylene chloride. Methylene chloride also increases carboxyhemoglobin levels. Carboxyhemoglobin can interfere with the oxygen carrying capacity of blood and is a particular problem for pregnant women, smokers, those whose blood has limited oxygen carrying capacity, and individuals with asymptomatic or undiagnosed cardiac disease. The eyes and skin are also irritated by contact with liquid methylene chloride.
Q. How does exposure to methylene chloride occur?
A. Employee exposure can occur through inhalation or skin absorption.
Q. What are common uses for methylene chloride?
A. It is frequently used as a process solvent, a degreasing agent, a cleaning solvent, a component of paint strippers, in propellant mixtures in containers for spraying aerosols such as adhesives, and as an auxiliary blowing agent in polyurethane foam manufacturing.
Q. What types of work operations are sources of overexposure to methylene chloride?
A. Many different kinds of work operations, such as methylene chloride manufacturing, furniture paint stripping, metal cleaning, foam blowing, and pharmaceutical manufacturing may overexpose employees to methylene chloride.
Regulatory Text Information
Scope and Application
Q. How is the extent of the standard's coverage of an employer determined?
A. The extent of coverage depends on the level of employee exposure to methylene chloride. The highest level of coverage occurs when employees are exposed above both the 8-hour TWA PEL and the STEL and could contact liquid methylene chloride. In that case all the requirements of the standard apply. The lowest level of coverage occurs when employees are exposed below both the action level (AL) and the STEL and are not subject to skin contact with liquid methylene chloride. In that case, employers are only required to document that the exposures are that low and to provide employee information and training.
Q. What workplaces are covered by the standard?
A. The standard applies to all workplaces covered by OSHA in general industry, construction, and shipyards, where methylene chloride is produced, released, stored, handled, used, or transported. It applies to workplaces in the marine terminal and longshoring industries only where the industry-specific standards do not address hazards to which employees are exposed. The standard does not apply to the agriculture industry. (See page 1572 of Federal Register, Volume 62, Number 7, January 10, 1997.)
Q. Which employers in the covered industry sectors must make an initial determination of their employees' exposures to methylene chloride?
A. All employers in the covered industry sectors with workplaces where methylene chloride is known to be present must make an initial determination of employee exposure.
Q. When is exposure monitoring not required in order to make initial determinations of employee exposure to methylene chloride?
A. Initial exposure monitoring is not required where:
Q. When is it not necessary to monitor employee exposure to methylene chloride with the accuracy specified in the standard?
- The employer has objective data which demonstrate that employees cannot be exposed at or above the action level or the STEL for methylene chloride; or
- The employer has performed exposure monitoring which meets the requirements of this section within the year prior to the effective date of the final rule. The monitoring must have been of workplace conditions that are similar to conditions existing at the time the rule becomes effective.
A. The accuracy of monitoring requirement of the standard does not apply when the workplace or work operation is transient and employees are exposed on fewer than 30 days a year. In this situation, employers are permitted to use direct reading instruments, such as detector tubes, to estimate exposure and determine what protective measures to provide. While these simple measurement tools are often not as accurate as other types of monitoring methods, they have the advantage of immediate results and no delay in the provision of protection. Since some short-term jobs, such as construction projects, may not last long enough for analytical results to be returned from conventional monitoring methods, these direct reading instruments provide an effective compromise that will nevertheless ensure protection for employees in these types of operations.
Q. What conditions must objective data satisfy in order to exempt an employer from the requirement to perform initial monitoring of employee exposure to methylene chloride?
A. The objective data must establish the highest methylene chloride exposures likely to occur in the workplace under reasonably foreseeable conditions of processing, use, or handling. The employer must document the data and subsequent analysis that leads to the conclusion that employees cannot be exposed at or above the action level or the STEL for methylene chloride.
Q. What would be an example of when objective data might be used to provide an exemption from the initial employee exposure monitoring requirement?
A. In a number of products made from, containing, or treated with methylene chloride, it is likely that an insignificant amount of methylene chloride will be present and that there will be minimal exposure. Where this is the case, the exemption provides fabricators or users of the products a means to avoid the burdens of compliance with the standard. The determination that airborne concentrations of methylene chloride will not exceed the action level or the STEL need not be based on data generated by the employer but may, for example, be based upon information provided by the manufacturer of the product in question.
Q. What are the minimum conditions for when a personal breathing zone air sample taken for one employee can be considered representative of another employee's 8-hour time-weighted average (TWA) exposure to methylene chloride?
A. A personal breathing zone air sample may be considered to be representative of another employee's 8-hour TWA exposure when the employer has taken one or more personal breathing zone air samples throughout the duration of exposure for at least one employee who is expected to have the highest methylene chloride exposures in the same job classification in the same work area during every work shift. As long as the employees in the same job classification have similar exposures, the employer may use the result from the employee who was selected for exposure sampling to represent the exposure of the group of employees.
Q. May an employer also use one or more employees to represent the maximum 15-minute exposure to methylene chloride of all of the employees in each job classification in a work area during every work shift?
A. Yes. The personal breathing zone air samples taken must indicate the highest likely 15-minute exposures that would occur to employees in that job classification during the work shift.
Q. May an employer use representative monitoring to comply with a requirement to perform initial monitoring of employee exposures to methylene chloride?
A. Yes, although the best way to characterize employee exposure is to measure each individual employee's exposure.
Q. In accordance with 29 CFR 1910.1052(d)(4)(i), the employer must perform exposure monitoring when a change in workplace conditions indicates that employee exposure may have increased. Is this additional monitoring required after every change in production, process, etc.?
A. Additional monitoring is not required after those changes in production, process, etc., for which the employer has another sound basis for concluding that the changes have not resulted in a significant increase in employee exposures.
Q. What is a significant increase in employee exposures?
A. OSHA interprets a significant increase in employee exposures to be an instance where at least:
Q. According to 29 CFR 1910.1052(d)(6)(i), the employer must provide affected employees or their designated representatives an opportunity to observe any monitoring of employee exposure to methylene chloride conducted in accordance with the standard. May employers choose who will be provided the opportunity to observe the monitoring?
- one previously unexposed employee is exposed at or above the action level for methylene chloride;
- one employee's exposure increases from below the action level to at or above the action level;
- one employee's exposure increases from below one or both of the PELs to above one or both of the PELs;
- one employee's exposure increases to a level where the employee needs to switch to a respirator assigned a higher protection factor; or
- one employee exposed at or above the action level or above the STEL incurs a 50 percent or greater increase in exposure.
A. No. The affected employees choose who will observe the monitoring.
Q. Must every employee entering the regulated area wear a respirator?
A. Where a reliable estimate of the air concentration of methylene chloride and the time to be spent by the employee in the regulated area shows that there is no potential for overexposure, the employee is not required to wear a respirator while in the regulated area.
Q. Must the regulated area consist of a fixed location or locations within the plant?
A. No, the extent of a regulated area may vary depending on the work activity involved. For example, an area in which employee methylene chloride exposures are not normally over the 8 hour TWA or STEL, because the methylene chloride is contained inside sealed equipment, may need to be designated as a regulated area during work which requires opening the equipment.
Q. Must an employee who is exposed over the 8 hour TWA limit wear a respirator at all times while in the regulated area?
A. Yes. However, as explained in the preceding answer, the extent of the regulated area may vary during the work shift. If an employee's work station is only within a regulated area during a portion of the work shift, the employee need only use a respirator during that period.
Q. If the location or boundaries of the regulated area change(s) during the work day, how must the regulated area be demarcated?
A. The employer must demarcate the regulated area in any manner that adequately establishes and alerts employees to the boundaries. Movable signs, temporary barriers, or a system of warning lights are among the methods employers could use to demarcate a regulated area that changes in size during the work day.
Q. What factors must employers consider in determining how to demarcate regulated areas?
A. Employers must consider such factors as the configuration of the area, whether the regulated area is permanent, the airborne methylene chloride concentration, the number of employees in adjacent areas, and the period of time the area is expected to have exposure levels above either PEL.
Q. What employee activities must the employer prohibit in regulated areas?
A. The employer must ensure that within a regulated area employees do not engage in nonwork activities which may increase dermal or oral exposure to methylene chloride. For example, the employer must ensure that employees do not eat, drink, smoke, chew tobacco or gum, or apply cosmetics in the regulated area.
Methods of Compliance
Q. Does the methylene chloride standard require written compliance plans?
A. No. In 1991 OSHA proposed a requirement that employers establish and implement a written compliance plan which would describe how employee overexposures to airborne methylene chloride would be reduced or brought below the PELs. However, the Agency removed this provision from the final rule in order to reduce employer paperwork. Regardless of size, employers are not required to produce written compliance plans. Note: According to 29 CFR 1910.1052(d)(5), within 15 working days after an employer receives monitoring results, it must notify the employee in writing of these results, and if the results indicate an overexposure, the employer must describe in the written notification the corrective action being taken to reduce employee exposure to or below the 8-hour TWA PEL or STEL and the schedule for completion of this action.
Q. When does the standard require employers to use supplied-air respirators to protect employees overexposed or subject to overexposure to methylene chloride?
A. The standard requires that for all circumstances except during emergency escape, the employer must use supplied-air respirators to protect employees overexposed or subject to overexposure to methylene chloride.
Q. Why does the standard require employers to use supplied air respirators?
A. The standard requires supplied air respirators because methylene chloride breaks through the chemical cartridges and canisters used on air purifying respirators in too short a time for these respirators to provide reliable protection. Moreover, methylene chloride provides inadequate warning of when it breaks through chemical cartridges and canisters because the odor threshold concentration level is higher than the PEL values.
Q. May employers use the controlled negative pressure (CNP) method or the ambient aerosol method for quantitative fit testing of respirators?
A. These instruments are permitted for quantitative fit testing. Protocols for their use are contained in Appendix A of the revised respiratory protection standard (29 CFR 1910.134) that was published in the Federal Register on January 8, 1998.
Q. What action must employers take to comply with 29 CFR 1910.1052(j)(1)(iii), which requires employers to make medical surveillance available to employees who may be exposed to methylene chloride during an emergency?
A. Employers who have identified operations where a potential for an emergency involving methylene chloride exists must take the necessary action to ensure that, in the event of an emergency, facilities will be available and medical assistance will be rendered to exposure victims promptly by physicians or other licensed health care professionals knowledgeable about the toxic effects of methylene chloride.
Q. Does the Methylene Chloride Standard contain requirements for labeling and for preparing material safety data sheets (MSDSs)?
A. Employers who have already met their longstanding requirements to comply with the Hazard Communication Standard (29 CFR 1910.1200) will have no additional duties with regard to labels and MSDSs under the Methylene Chloride Standard. The Methylene Chloride Standard simply indicates what specific hazard information must be provided on labels and material safety data sheets.
Employee Information and Training
Q. How does the employer determine when employee information and training must be updated?
A. The standard does not provide a specific time period for updating the training and information. Instead, it requires that information and training be updated as necessary to ensure that each employee exposed above the action level or the STEL maintains a good understanding of the principles of safe use and handling of methylene chloride in the workplace. Employers can assess exposed employees' understanding in various ways, such as observing their actions in the workplace. For example, a pattern of not using appropriate protective equipment or following safe work practices may be an indication that additional information and training is required.
This is a performance-oriented requirement that allows each employer to determine how much additional training and information to provide and how often to provide it. The employer must also update the training as necessary whenever there are workplace changes, such as modifications of tasks or procedures or the institution of new tasks or procedures, which increase employee exposure, and where those exposures exceed or can reasonably be expected to exceed the action level.
Q. Does the methylene chloride standard permit electronic retention and transmission of records?
A. Electronic retention and transmission of records is acceptable provided the confidentiality of medical records is retained and there is compliance with all relevant provisions of the standard.
Q. How does the required exposure monitoring record for employers with fewer than 20 employees differ from the required exposure monitoring record for employers with 20 or more employees?
A. Employers with fewer than 20 employees may provide and maintain less information. These employers may exclude the following information from the record:
In OSHA's view, an employer with fewer than 20 employees is very likely to know intimately the operations of the business, including information about exposure monitoring and the use of personal protective equipment. Therefore, the information can be excluded from the employee's records without compromising employee safety and health.
- The operation involving exposure to methylene chloride which is being monitored;
- Sampling and analytical methods used and evidence of their accuracy; and
- Type of personal protective equipment, such as respiratory protective devices, worn, if any.
Q. Are laboratory test results obtained for the purpose of medical surveillance of employees exposed to methylene chloride included in the written medical opinion provided to the employer?
A. The written medical opinion provided the employer must not include any laboratory test results.
Q. Must the employer ensure the preservation, retention, and accessibility of laboratory test results obtained for the purpose of medical surveillance of employees exposed to methylene chloride?
A. The Methylene Chloride Standard does not list laboratory test results among the items that must be included in the medical surveillance record. However, the laboratory test results are employee medical records that must be retained, preserved, and made accessible in accordance with 29 CFR 1910.1020, Access to employee exposure and medical records.
Q. Are companies engaged solely in the fabrication of flexible foam products which use adhesives containing methylene chloride and have 20-99 employees considered to be "Polyurethane foam manufacturers" that are eligible for the extended compliance deadlines for Polyurethane foam manufacturers with 20-99 employees?
A. No. The extended compliance dates for Polyurethane foam manufacturers with 20-99 employees apply only to those manufacturers that use methylene chloride in blowing the foam. If the only use of methylene chloride is in an adhesive, the extended compliance dates do not apply.
Q. Is a fabrication operation that uses an adhesive containing methylene chloride and is located within a Polyurethane foam manufacturing facility subject to a different compliance schedule than the foam manufacturing (foam blowing) operation?
A. No. If a Polyurethane foam manufacturer has 20-99 employees and uses methylene chloride to blow foam, then the compliance schedule for Polyurethane foam manufacturers with 20-99 employees applies for all the operations in the facility involving methylene chloride exposure.
- Purpose. The June 1, 1998 memorandum from the Cincinnati Technical Center to Regional Administrators is reproduced here to provide OSHA compliance officers with easy access to information on equipment available to them for tracking their methylene chloride exposures during an inspection of a work place.
- Reproduced Memorandum.
||Occupational Safety and Health Administration|
Directorate of Technical Support
Cincinnati Technical Center
435 Elm Street, Suite 500
Cincinnati, Ohio 45202
TEL: 513-684-3721 FAX: 513-684-2630
March 3, 2000
ARAs for Technical Support
||Robert T. Williams|
||Assessment Tools Update for Methylene Chloride|
As a reminder of the June 1, 1998 memo from the CTC regarding the immediate assessment of CSHO exposure to methylene chloride during inspections of workplaces and/or to screen certain operations to determine if further sampling is needed, the Salt Lake Technical Center (SLTC) has performed additional testing concerning the use of direct reading tools. The need for immediate assessment is critical in order to provide respiratory protection for the CSHO depending on the level of methylene chloride present as stated in the current regulation.
From additional testing on detection systems for methylene chloride, the SLTC has confirmed that the Gastec detector tube (# 138) does not indicate methylene chloride at the action (12.5 ppm) and TWA (25 ppm) levels. Testing has shown that the Draeger (#6724601) and the Kitigawa (#180s) detector tubes do show indications of methylene chloride at these levels. These tubes are available through the CTC's Agency Expendable Supplies Program (AESP). The hand pumps for these tubes are available through the CTC's Agency Loan Equipment Program (ALEP) in case your office does not own any.
Infrared analyzers such as Foxboro's Miran 1BX or SapphIRe have been tested and can detect methylene chloride at the action and TWA levels. Testing has also shown that photo ionization detectors (PID) can detect methylene chloride but will give low values compared to actual levels when the PID is calibrated with isobutylene and no calibration factors are applied. These instruments are available on loan from the CTC as well. Results of the SLTC's tests on all the above direct reading systems can be found in their report, "Utilization of Direct Reading Devices for the Measurement and Tracking of Methylene Chloride Exposure." Methods for direct reading devices will be generated from the data used for the report above.
It is the Centers' opinion that using detector tubes is the simplest method for immediately determining levels of methylene chloride being present as long as the limitations of detectors tubes are recognized. However, from laboratory evaluations, the Foxboro MIRAN SapphIRe gave the best overall results. Other instruments, such as photo ionization detectors can be used if their drawbacks are kept in mind. For compliance purposes, sampling tubes using OSHA methods #80 or #59 are still employed.
Please feel free to call me at (513) 684-6395 or Duane Lee of the SLTC at (801) 487-0680 if you have any questions regarding this issue. Further information is also available on the DTS Limited Access page under the SLTC Services. Thank you.
Evaluating the Methylene Chloride Hazards and the Effectiveness of the Protective Measures Used
- If the air concentrations of methylene chloride measured in the work area with detector tubes or other direct reading instruments are below the 12.5 ppm action level, then you should use professional judgement to determine what additional sampling to perform. Because concentrations of methylene chloride in air can vary dramatically, and because direct monitoring and detector tube sensitivities have limited accuracy at low levels, in some cases you, the compliance officer, will find it appropriate to conduct personal sampling of the workers to establish whether the action level has been exceeded.
- Two types of sampling tubes are available for personal sampling. For STEL sampling, you may use a Carbosieve S-III synthetic charcoal sampling tube (OSHA method #80). For 8-hour TWA sampling, this sample tube must be changed hourly based upon the recommended flow rate of 0.05 L/min, or a two hour sample can be obtained with this sample tube using a 0.025 L/min sampling rate.
- An alternative sampling tube for both STEL and for 8-hour TWA monitoring is the large three-section sample tube containing conventional coconut shell charcoal (OSHA method #59). You can use this sample tube to sample for 3.3 hours at 0.05 L/min; you can also use it at a lower flow rate (0.025 L/min) to provide a 6.6 hour sampling time. At this reduced sampling rate, you can change the sampling tube at the lunch break, thus using two sample tubes to monitor each worker over an eight-hour work day.
- Area air sampling may be required to establish whether the boundary of the regulated area complies with 29 CFR 1910.1052(e). You can use the large OSHA #59 sample tubes at a sampling rate of 0.025 L/min to obtain an area sample in a location suspected of exceeding either the 25 ppm 8-hour TWA or the 125 ppm STEL. Alternatively, you can use OSHA method #80 tubes and follow the sampling rates and time periods presented above for personal sampling. Also, you may find that direct reading measurements obtained with detector tubes or a photo ionization detector (PID) are useful for determining the location for conducting area monitoring.
- You can also collect gas bag samples as a means of obtaining air samples. You can then "analyze" these samples on site using a detector tube or a PID to determine if the air concentration is in excess of the 8-hour TWA PEL or the STEL. This method may be most appropriate in a situation where direct reading PIDs are not available to frequently monitor the methylene chloride concentration in the area over time, and you want to obtain a better picture of the exposure over time than is available from a single detector tube "grab sample" of the air.
- You can use smoke tubes to examine the performance of local exhaust ventilation controls by observing the ability of the local exhaust system to capture discharged smoke.
- You can also use smoke tubes to determine whether air flows from methylene chloride work or regulated areas to nonregulated areas.
Protective Clothing and Equipment Evaluation
- Whereas (f)(3)(ii) requires that incidental spills be promptly cleaned by employees who use the appropriate personal protective equipment and are trained in proper methods of cleanup, you should exercise caution in determining the size of a spill which can be classified as incidental. Methylene chloride is a very volatile solvent and has a high vapor pressure (440 mm Hg at 25 C). Thus, a large pool of methylene chloride spilled on the floor in an enclosed room with no ventilation could produce an air concentration in excess of 500,000 ppm. At this extremely high concentration, an oxygen deficient environment would exist; in addition to producing a narcotic effect it would cause a rapid loss of consciousness and subsequent death.
- Another useful example to illustrate the potential hazards created by methylene chloride spills would be a scenario in which a worker spills a quart of methylene chloride in an enclosed room with dimensions of 15' length by 15' width by 10' ceiling. Because methylene chloride evaporates rapidly (70% as fast as ethyl ether), it can be expected that the entire volume will be rapidly dispersed into the air in the room, resulting in an air concentration of over 5,700 ppm, which exceeds the 2,300 ppm IDLH level reported in the NIOSH 1997 pocket guide. (1990 NIOSH Pocket Guides lists IDLH as 5,000 ppm).
Under this scenario, the spill would not be classified as an incidental spill under OSHA's interpretation of 1910.120; consequently evacuation would be the only appropriate response. Efforts to mitigate the consequences of this spill would require that the employer implement an emergency response as described in 1910.120.
- Direct reading PID air monitors can be useful in determining sources of leaks and spills.
Supplied Air Systems Evaluation
- NIOSH studies indicate that skin absorption can be a significant route of exposure. It appears that dermal exposure to methylene chloride can occur without producing irritation.
Color-indicating patches are available from the Salt Lake Technical Center for evaluating the effectiveness of PPE against methylene chloride. Contact the Center for recommendations on how to use these patches.
Note: The above information was deleted in January 2013 because color-indicating patches are not known to be commercially available.
- The breathing air for supplied air systems must meet the air quality requirements of Grade D or better as specified in CGA specification G-7.1-1989.
- Compressed air supplied by oil lubricated compressors must be monitored frequently for carbon monoxide if the compressors are not equipped with continuous carbon monoxide monitors.
- Entry of contaminants into the supplied air system must be prevented either by locating the compressor air intake in an uncontaminated area or by in-line purification. Proper location will probably be the only practical means of preventing contamination of the breathing air with methylene chloride because of the inability to effectively filter it from air.
- Air line couplings must be incompatible with outlets of other gas services.
- NIOSH-approved respirators must be used. This approval process also applies to the air line hose and the length of hose. See 42 CFR Part 84.
- NIOSH-approved respirators must only be repaired with approved replacement parts.
29 CFR 1910.1052
29 CFR 1915.1052
29 CFR 1926.1152
Field Inspection Reference Manual
medical removal protection
Short Term Exposure Limit