Respirators for coke oven emissions

September 6, 1990

MEMORANDUM FOR: CYNTHIA WOLFE
Assistant Regional Administrator for Technical Support

THROUGH: LEO CAREY, Director
Office of Field Coordination

FROM: PATRICIA K. CLARK, Director Designate Directorate of Compliance Programs

SUBJECT: Coke Oven Emissions

This memorandum responds to the questions concerning coke oven emissions contained in the June 7 memorandum your office received from the Birmingham Area Office. Your office transmitted the memorandum to my office by cover memorandum dated June 11.

Question 1:

Are coke oven emissions a complex mixture of particulates, vapors, gases and fumes?

Answer:

The preamble to the standard for Exposure To Coke Oven Emissions, 29 CFR 1910.1029, describes coke oven emissions as a complex mixture of particulates, vapors and gases. The preamble does not distinguish between the types of particulates present in coke oven emissions, but fume is present.

Question 2:

Are organic vapors which contain carcinogens produced and/or given off during the coking process?

Answer:

Yes.

Question 3:

If the answer to 1 and 2 above is yes, will a particulate respirator for dust and mist provide the proper protection?

Answer:

According to the standard for exposure to coke oven emissions, respirators approved for protection against dust and mist by the National Institute for Occupational Safety and Health (NIOSH) provide proper protection. This is allowable only if the respirator is not a single-use or a disposable respirator. No single-use or disposable respirator may be used to protect employees against coke oven emissions.

Question 4:

Is the 3M 9900 (Approval No. TC-21C-176) approved for coke oven emissions?

Answer:

No. There are no respirators approved by NIOSH for coke oven emissions. The 3M 9900 is approved by NIOSH for dust and mist but Table I in the standard for exposure to coke oven emissions prohibits the use of single-use respirators for protecting employees. The 3M 9900 is an example of the type of respirator identified by OSHA as a single-use respirator. OSHA has determined that non-powered, air-purifying respirators with nonelastomeric facepieces, such as the 3M 9900, are prone to have greater leakage at the sealing edges and do not provide as high a protection factor as their counterparts with elastomeric facepieces.

Question 5:

Are fumes still considered a hazard in the coke manufacturing process?

Answer:

The preamble to the standard for exposure to coke oven emissions does not give separate attention to the nature of the health hazard of fume produced in the coke production process. The degree of health hazard posed by coke oven emissions is indicated by the airborne concentration of the benzene soluble fraction of total particulate matter (BSFTPM). When the standard was first published in the Federal Register on October 22, 1976, Table I, listing the required respiratory protection for coke oven emissions, stated that respirators for dust, mist and fume were required. This was an error, however, and a correction document published in the Federal Register on January 18, 1977, corrected the table to state that only dust and mist respirators are required.

Question 6:

Which class of respirators is recommended for protection against coke oven emissions by OSHA and NIOSH?

Answer:

The original intent of the standard for exposure to coke oven emissions was to require by January 20, 1979, only respirators approved by NIOSH for protection against coke oven emissions must be used. NIOSH never approved any respirators for protection against coke oven emissions, however. Consequently, as indicated in the answer to question (3), respirators, except single-use respirators, that are approved by NIOSH for dust and mist comply with the standard.

Since coke oven emissions contain carcinogens, NIOSH recommends that positive pressure, atmosphere-supplying respirators be used for protection against exposure.

[June 7 regional memorandum and its supporting correspondence and materials reproduced on OSHA page; omitted here.]