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.

February 19, 1986

Mr. Neal A. Iund
Chief Mechanic
Bernina Sewing Machine Co., Inc.
70 Orchard Drive
North Salt Lake UT 84054

Subject: Double Insulated vs. Electrically Grounded Sewing Machines for School Use

Dear Mr. Iund:

Although many schools, municipal governments, and public sector employers utilize OSHA's regulations to establish minimum acceptable standards, we do not enforce our standards in these work situations.

It has consistently been the policy of this Agency not to approve specific types or brands of equipment. Neither do we accept, nor in fact reject, products by brand name except in the most unusual circumstances.

It is, however, generally recognized that within the scope of THE NATIONAL ELECTRIC CODE NFPA No. 70-1978, Article 250-45(d) Exception No. 2, and OSHA General Industry Standards 29 CFR 1910.304(f)(5)(v)(c)(8), double insulation is an effective means of protecting against the hazards of electrical shock when "the normally non-energied portions of the equipment become energized through improper use or malfunction". If this is the case with regard to BERNINA SEWING MACHINE, then you will have met the requirements that the equipment be "effectively grounded".

If you are in doubt as to your compliance with the grounding requirements of NEC Article 250-45(d), I suggest you supply all pertinent design specifications and testing documentation to:

Mr. Donald A. Shay, Director
Office of General Industry
Compliance Assistance
U. S. Department of Labor
Occupational Safety and Health
200 Constitution Avenue, N.W., Room N-3608
Washington DC 20210
(202) 523-8031


Regional Administrator - VIII
Occupational Safety and Health