March 1, 2008
Suppose you, like many employers, need flame-resistant (FR) protective uniforms for exposures that are not electric arc hazards. Let’s look at a couple of hypothetical safety pros’ situations that go beyond electric arc protection; as we do, you may end up finding solutions to your problems.
I’m the safety manager for a multinational oil field services company. We work in both the United States and Canada. We probably have a couple of electricians, but our main hazard is hydrocarbon flash fire.
It sounds like your employees are going to be covered by a couple of standards. In Canada, the standard is CAN/CGSB 155.20 Workwear for Protection Against Hydrocarbon Flash Fire. This standard identifies three classifications of workwear: Type 1, single-layer garments; Type 2, multilayer garments; and Type 3, disposable garments. Single-layer garments are those constructed from a single fabric, but also include bonded, laminated, coated and quilted fabrics. Multilayer garments have an outer shell fabric plus an inner lining fabric or insulating material.
For Type 1 garments, the protective fabric is tested for flame resistance before and after 50 cycles of laundering with detergent by a medium temperature (50ºC) formula. The average damaged length cannot exceed 100mm in either direction and the Afterflame cannot be more than two seconds with no melting or dripping. Both contact and spaced thermal protective performance (TPP) are determined, and these results have to be shown on the garment label. A minimum average spaced TPP of 6.0 is required for Type 1 garments.
For multilayer garments, the outer shell and inner lining protective fabrics are tested for flame resistance. Performance requirements are the same as for single-layer Type 1 garments. Multilayer garments are tested for TPP by the contact method only. The composite of all components in a multilayer garment must have an average contact TPP of 5.0 or greater. An important exemption specifies that encapsulated down insulation and vapor barriers placed on the outside of the insulation layer are not required to be tested for flammability.
Type 3 disposable garments are required to meet the same flame-resistance requirements as single-layer garments, but cannot be worn alone, only over flame-resistant garments.
The 155.20 standard has additional requirements for thermal shrinkage, heat resistance, thread and hardware performance, and labeling requirements.
For your U.S. employees…
Your U.S. employees are subject to National Fire Protection Association (NFPA) 2112 Standard for Flame Resistant Garments for Protection of Industrial Personnel Against Flash Fire. This standard follows some of the Canadian requirements such as both contact and spaced TPP, thermal shrinkage and heat resistance. It also requires a maximum of 100mm damaged area in flame-resistant testing, but increases the laundry durability test from 50 to 100 washings.
Major differences between the U.S. and Canadian standards include requiring TPP testing by both spaced and contact methods and flash fire exposure requirement. A standard coverall is exposed to a simulated flash fire on an instrumented mannequin. There cannot be more than 50 percent predicted body burn following a three-second exposure. Finally, third-party certification is required for all garments. The U.S. standard does not distinguish between single- and multilayer garments and makes no provision for disposables.
Welding hazards, anyone?
I work for a company that makes automobile frames. We have teams of production welders who assemble the frames. Our hazard is garment ignition from welding sparks and slag.
Do your employees wear their leather aprons, gloves and gauntlets?
That’s what I thought. OSHA regulation 29 CFR 1910.252(b)(3) requires employers to provide clothing that minimizes the potential for ignition, burning or trapping hot sparks for individuals with welding, cutting or brazing duties. Also, the American National Standards Institute (ANSI) standard ANSI/ASC Z18.104.22.168 states that an employer should provide clothing that minimizes the potential for ignition, burning or trapping hot sparks for individuals with welding, cutting or brazing duties. This standard also states that those materials that can melt and cause severe burns should not be used as clothing when welding or cutting.
Your best solution probably is to require the use of primary protection and select flame-resistant secondary protective garments that meet the requirements of ASTM International Standard F2302 for labeling protective clothing as heat- and flame-resistant. Under this standard, fabric laundered ten times must have an average of no more than 6.0 inches damaged area or two seconds Afterflame when tested for flame resistance.
Requiring that FR garments for any general industry hazard application at least meet the performance requirements of F2302 will ensure that you get a garment that was tested for vertical flame resistance.