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Standard Interpretations - Table of Contents
• Standard Number: 1910.1018; 1910.1018(a); 1910.1018(b); 1910.1018(p)(3) ; 1910.1200; 1910.1200(b)(2); 1910.1200(c)

This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any situation not delineated within the original correspondence.

July 17, 2008

Mr. Robert N. Dingess, President
Mercer Strategic Alliance, Inc.
209 Pennsylvania Avenue, SE
Washington, DC 20003

Dear Mr. Dingess:

Thank you for your January 3, 2008, letter to the Occupational Safety and Health Administration's (OSHA's) Directorate of Enforcement Programs (DEP). In your letter you requested clarification of OSHA's Inorganic Arsenic Standard 29 CFR 1010.1018. In addition, you inquired about a chemical manufacturer's responsibility with regard to inorganic arsenic under OSHA's Hazard Communication Standard (HCS), 29 CFR 1910.1200, when it is bound in glass beads. Your paraphrased statement and questions are presented below, followed by our response.

Statement: It has been alleged that some recycled glass beads used in pavement marking applications contain in excess of 1,300 parts per million (ppm) inorganic arsenic. Glass beads are utilized by blending them with paint or dropping them onto freshly-laid paint or thermoplastic. After the life of the product is exhausted, the material is removed from the roadway through water blasting or grinding operations. It is our understanding that the process of vitrification inextricably binds any heavy metals in glass, rendering it inert. Our tests have shown that even when glass beads are ground to dust, heavy metals are not released. We have not been able to uncover any evidence that heavy metal contained in glass beads poses a health threat to workers or the environment.

Question 1: Does OSHA take into consideration the type of casing material or chemical compound (i.e., paint, thermoplastic, glass beads) when determining employee exposure?

Response 1: Both the Hazard Communication and Inorganic Arsenic standards take into account whether the chemical is available for employee exposure. The Inorganic Arsenic Standard's requirements are triggered by "all occupational exposures to inorganic arsenic." 29 CFR 1910.1018(a). However, OSHA has interpreted this standard's labeling and monitoring requirements as not applicable "where there is no realistic possibility of employees being exposed above the action level defined under 29 CFR 1910.1018(b)." (Letter to Charles R. McDuff, "Initial monitoring and labeling for inorganic arsenic is not required when exposure could not be above the exposure level"(12/13/1978.))

Likewise, the requirements of the HCS are triggered only where a chemical is "known to be present in the workplace in such a manner that employees may be exposed under normal conditions of use."(29 CFR 1910.1200(b)(2). "Exposure" is defined as including "potential (e.g., accidental or possible) exposure." 29 CFR 1910.1200(c). OSHA has interpreted this language as excluding "substances for which the hazardous chemical is inextricably bound or in not readily available, and, therefore, presents no potential for exposure." (Inspection Procedures for the Hazard Communication Standard, CPL 02-08-038, Appendix A.)

It is the duty of the employer (under the inorganic arsenic standard) and the manufacturer/importer (under the hazard communication standard) to make these determinations. While it might be possible that the inorganic arsenic in the glass beads you reference may not be available for exposure under these standards, OSHA does not have the necessary information to determine whether these standards apply in the circumstances you describe.

Question 2: In developing Material Safety Data Sheets (MSDSs) for glass beads containing heavy metals, our testing of glass bead material combined with an examination of the scientific research relative to the use of vitrification, indicate that there is only trace worker and environmental exposure to heavy metals fused in glass beads. What are OSHA's requirements for manufacturers to list these heavy metals? Should the listing be based on total metal content or on worker exposure to the heavy metals?

Response 2: Chemical manufacturers are required to list any chemical that poses a health risk to employees who are exposed during the use of the chemical. If the hazardous chemical is a mixture which has not been tested as a whole, the manufacturer has to list all of the ingredients that are determined to be health hazards and which comprise 1% or greater of the composition, or .1% or greater of the composition, if the chemical is a carcinogen. Also, if the ingredients are determined to be health hazards and comprise less than 1% (0.1% for carcinogens) of the composition, but there is evidence that the ingredient(s) could be released from the mixture in concentrations which would exceed the OSHA permissible limits (PELS) or could present a health risk to employees, then these chemicals must also be listed.

However, if the glass beads meet the definition of an "article," you would not have to list these chemicals on the MSDS. The Hazard Communication Standard (HCS) at 29 CFR 1910.1200 defines an article as "a manufactured item: (i) which is formed to a specific shape or design during manufacture; (ii) which has end use function (s) dependent in whole or in part upon its shape or design during end use; and (iii) does not release more than very small quantities, e.g., minute or trace amounts of a hazardous chemical . . . and does not pose a physical hazard or health risk to employees." Again, the hazard determination of the product is up to the manufacturer to conduct and whether or not the hazardous chemical is available for exposure to employees under the normal conditions of use of the product. You stated that your studies have shown only trace amounts of employee exposure to heavy metals fused in glass beads. It is possible that blasting and/or grinding of glass beads could lead to greater exposures. If these actions are a normal condition of use of the product, employee exposures resulting from any of these types of use of the product would have to be considered. It is manufacturers' responsibility to determine whether these trace amounts pose a health risk to employees under normal conditions of use; OSHA does not have such data available.

When a hazard determination is conducted by the manufacturer, the resulting information is normally provided on the MSDS for the product. This hazard information is then transmitted to the downstream user on the data sheet shipped by the producing manufacturer. The information on the MSDS reflects those physical and health hazards that are expected to exist, based on the end use of the product (during normal operations or in a foreseeable emergency). For example, as the manufacturer, you are obligated to supply the downstream user of your product (road surface painters) with an MSDS that adequately reflects the hazards associated with the application of your surfacing product. Likewise, if the manufacturer foresees that under normal conditions of use, the paint will be removed by blasting or grinding, the hazards associated with that process should be reflected in the MSDS. (Letter to Allison Keane, "Application of the hazard communication standard to latex paints containing less than 6% silica" 2/11/2004).)

Question 3: Is there any evidence that heavy metals in glass beads pose a health risk to employees during the installation or removal process?

Response 3: Please see response to question 2. Additionally, as you are aware, inorganic arsenic is a known human carcinogen, and, as such, it poses a health risk to employees who may be exposed to it. While the information on a chemical's MSDS is governed by the Hazard Communication Standard, the labeling requirement for materials containing inorganic arsenic is contained in 29 CFR 1910.1018, which states that "the employer shall apply precautionary labels . . . except when the inorganic arsenic in the product is bound in such a manner so as to make unlikely the possibility of airborne exposure to inorganic arsenic . . . (please see 29 CFR 1910.1018(p)(3)." Also, you may wish to contact the National Institute of Occupational Safety and Health (NIOSH) for further information. NIOSH can be reached through their website at

Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA requirements are set by statute, standards, and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information.

To keep apprised of such developments, you can consult OSHA's website at If you have any further questions, please feel free to contact the OSHA Office of Health Enforcement at (202) 693-2190.


Richard E. Fairfax, Director
Directorate of Enforcement Programs

Standard Interpretations - Table of Contents

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