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 https://www.osha.gov.

April 10, 1986

Mr. John C. Lumsden
Vice President, Health
ELB Associates, Monitor Inc.
605 Eastowne Drive
Chapel Hill, North Carolina 27514

Dear Mr. Lumsden:

This is in response to your February 6 letter to Ms. Susan Harwood, concerning the cotton dust standard, 29 CFR 1910.1043.

The Occupational Safety and Health Administration (OSHA) interprets the cotton dust standard as prohibiting any daily employee exposure in excess of 1600 ppm hours in yarn manufacturing, 6000 ppm hours in slashing or weaving, and 4000 ppm hours in cotton waste processing. For example, an employee who works a 10-hour day at a yarn manufacturing operation may not receive a 10-hour, time-weighted-average exposure in excess of 1600 ppm hours - 10 hours = 160 ppm. This interpretation is supported by OSHA's notice of respirator-use enforcement policy appearing in the Federal Register, Vol. 45, No. 251, December 30, 1980, pp. 85737 and 85738.

If, when disregarding any employee protection afforded by respirators, there are no 8-hour periods during the day when a relevant employee is exposed above the applicable permissible exposure limit, the employer would not have to implement additional engineering or work practice controls to keep the relevant employee's extended work day exposure below the applicable ppm hour limit. Instead, the employer may use respirators to provide the additional required protection. This is so because OSHA believes the permissible exposure limits are set near the lowest values achievable with engineering and work practice controls.

Provision 29 CFR 1910.1043(i)(1)(ii) requires that each employee exposed to cotton dust be provided the training program at least annually. Moreover, the provision requires additional repeating of the training program when job assignments or work processes change, or when employee performance indicates a need for retraining.

With respect to yarn for weaving, the permissible exposure limit of 200 micrograms of respirable cotton dust per cubic meter of air applies for all handling operations up to the slashing stage regardless of where the handling takes place. If the yarn is not for weaving and is for knitting use, then all handling of the yarn connected with knitting operations is exempt from the cotton dust standard.

Thank you for contacting OSHA. Please feel free to contact us again anytime we may be of service.


John B. Miles, Jr., Director
Directorate of Field Operations

February 6, 1986

Ms. Susan Harwood
Division of Standards
200 Constitution Avenue, NW
Washington, DC 20210

Dear Susan:

Thank you for your interpretation of the cotton dust standard as it applies to the cotton waste spinning industry. We are proceeding on the basis that it would be classified as waste processing.

I have three other questions to ask concerning this standard which I would like for you or your associates to help us with.


With the advent of 10 & 12 hour shifts in the cotton textile mills, we originally adjusted the PEL downward. Shortly thereafter we received the OSHA opinion that PEL's would remain the same regardless of length of shift, but I cannot find any reference to this second decision. Alabama is now reducing the PEL for long shifts while other states do not. What is OSHA's position on this?


Some are interpreting (I)(ii), under Employee Education Training as requiring training on initial assignment only and not annually thereafter. It can be read this way if the comma after "cotton dust" is ignored. Should the comma be an "or"?


For winding operations not associated with yarn manufacture, as we sometimes find in dye houses, finishing plants, etc., we do not have a clear PEL. If yarns are being wound on dye cones or otherwise repackaged, are these operations exempt?

If you or your staff would comment on this, I would appreciate it.


John C. Lumsden, CIH
Vice President, Health