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 http://www.osha.gov.

December 17, 1979

Mr. J. F. Barrett
Resident Manager
Stone & Webster Engineering Corporation
P. O. Box 63
Lycoming, New York 13093

Dear Mr. Barrett

This is in response to your inquiry requesting clarification of the acceptance and use of a class C hard hat on heavy construction projects.

29 CFR 1926.100(b) requires that helmets for the protection of employees against impact and penetration of falling and flying objects meet the specifications contained in American National Standards Institute, Z89.1-1969, Safety Requirements for Industrial Head Protection. A class C helmet complying with ANSI Z89.1-1969 specifications is acceptable on construction projects for protection against impact and penetration of falling and flying objects. Class C provides no protection for electrical hazards.

29 CFR 1926.100(c) requires that helmets for the head protection of employees exposed to high voltage electrical shock and burns meet the specifications contained in American National Standards Institute, Z89.2-1871. A class B helmet complying with ANSI Z89.2-1971 specifications is required on construction projects for protection against high voltage electrical shock and burns. Normally, class B helmets provide the optimum protection for electrical workers and other crafts exposed to head hazards, electrical and nonelectrical.

If we may be of any further assistance, please feel free to call or write.