Respirator selection for isocyanate paint spraying

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

July 11, 1994

MEMORANDUM FOR: AREA DIRECTORS

ASSISTANT REGIONAL ADMINISTRATORS

FROM: JAMES P. DRAKE
Acting Assistant Regional Administrator for Technical Support

SUBJECT: Respirators and Isocyanates

This memorandum replaces the February 15, 1991, memorandum (copy attached) to Larry Falck, Acting Area Director, Jacksonville Area Office, concerning 1910.134 Interpretations, and clarifies the Agency's policy concerning respirator use for spray operations involving paints containing isocyanates. This action is necessary as the February 15, 1991, memorandum has been inadvertently applied to operations other than spray operations.

Positive pressure air-line respirators are the only NIOSH-approved respirators for employees engaged in spray operations and who are exposed to isocyanates. A full-facepiece respirator is required because of the eye irritant and sensitization characteristics of isocyanates. In situations where an overexposure to isocyanates has not been established and an improper type of respirator is being used a citation under 29 CFR 1910.134(b)(2) shall be issued, provided that the compliance officer documents that an overexposure is possible. Such documentation may be accomplished, for example, either by documenting the existing work practices of the employee during the spray operation or through air monitoring.

[OSHA Instruction CPL 2.103, dated August 26, 1994, Chapter III, paragraph C.3.c. discusses guidance to the field where violations of the respirator standard exist and Chapter III, paragraph C.3.a.(1)], discusses violations of air contaminant standards.

Should you have any questions concerning this matter, please contact Sven Rundman of my staff at (404)347-2281.