Welding and grinding: what disposable garments can and cannot do

Can you wear a Tyvek-type coverall while welding?

Not by the fabric manufacturer’s own warning. The non-FR disposables we carry are polypropylene (spunbond and SMS) or a polypropylene nonwoven laminated to a microporous film, and the manufacturer says not to use its non-FR cleanroom garments around heat, flames or sparks and reports the microporous fabric as melting down in a flammability test. OSHA’s electric power standard describes the same problem for a different trade: clothing that could melt onto the skin or ignite and continue to burn is prohibited, and its note names polypropylene and polyester among the fibers covered. Welding spatter and the slag from cutting are molten metal; a melting coverall over the welder’s leathers or FR shirt is a burn that the leathers were there to stop.

The welding standard itself does not list fabrics. It says the clothing varies with the size, nature and location of the work and sends the employer to 1910.132, where the hazard assessment is the document that records why a given garment was chosen. Heat and sources of high temperature that could ignite protective equipment are on the Appendix B survey list for exactly this reason.

What is an FR disposable for on a welding job?

Keeping the primary FR clothing clean. The PyroGuard FR sheet says it is secondary FR protective clothing designed to be worn over top of primary FR apparel to extend its life and protect it from dirt, grease, non-toxic liquids, sparks and flames. It lists electrical work, refinery turnarounds, oil and gas, manufacturing and industrial settings as applications. The fabric is treated with a phosphate-based fire retardant that the manufacturer says deprives flames of fuel, and it chars rather than drips. The flame test is ASTM D6413, which ASTM describes as a vertical flame resistance test of textiles under laboratory conditions that is not to be used to appraise fire hazard under actual fire conditions. None of that makes it a welding jacket: it has no leather, no arc rating and no claim against molten metal beyond the sparks and flames wording, and the manufacturer calls it secondary.

PyroGuard CRFR is the same idea with a chemical barrier and taped seams, for work where both splash and flash fire are a concern; the manufacturer states it is not designed to be worn as a primary FR garment, is single use and should not be washed or re-used. The welder’s own protection, the leathers, the helmet, the shaded lens under the Appendix B chart, is a separate decision that these garments do not touch.

What about grinding?

Grinding splits in two. Grinding steel throws sparks, which are hot metal particles, and the manufacturer’s sparks warning applies to the non-FR fabrics the same as it does for welding; a melting coverall sleeve on a grinder is the same burn. Grinding masonry, concrete, drywall, fiberglass, wood or plastic throws dust and no sparks, and that is a particle job. For particle work MicroGuard MP publishes dry and wet particle filtration efficiency by ASTM F2299 with the result No Particle Penetration and air permeability under 0.55 cfm, and SMS publishes a Helmke drum result of Category 1 and is described as an excellent dust and particulate barrier that breathes. Polypropylene is described for dust and particulates in non-hazardous environments. The construction silica standard, where it applies, controls the dust with engineering controls and respirators; its clothing lines are a ban on cleaning clothing with compressed air where that could add exposure, and protective clothing for monitoring observers where an area requires it. The coverall is about keeping the dust off the clothes and out of the truck.

Sleeves are the common half-measure on a grinding job: 8065 microporous sleeves and 4065 Body Filter 95+ sleeves cover the forearm where the dust lands, and are no more spark-proof than the coverall. Where the grinder makes sparks, the sleeve has to be the welder’s leather sleeve, not a disposable.

What does ASTM D6413 actually show?

ASTM’s scope says the method measures the vertical flame resistance of textiles, evaluating afterflame and afterglow as part of the measure, under controlled laboratory conditions, and that it shall not be used to describe or appraise the fire hazard or fire risk of materials under actual fire conditions. On the PyroGuard sheets the reported figures are char damage under 6 inches and after flame under 2 seconds, with the industrial catalog adding char lengths of 4.7 and 4.5 inches for CRFR. Read it as: the fabric stops burning when the flame is taken away and does not drip. It is not a rating against spatter, slag or arc, and the sheets do not claim one.

What should the hazard assessment say for a shop that welds and grinds?

Two lines. For welding, cutting, brazing and spark-throwing grinding: the primary protection is the welder’s FR and leather clothing chosen under 1910.252(b)(3) and 1910.132; non-FR disposable coveralls are not worn over it, per the manufacturer’s warning; if a disposable layer is wanted to keep the FR clothing clean, it is an FR disposable such as PyroGuard FR worn over primary FR, and it carries no arc rating. For dust-only grinding and cleanup: a particle coverall with a published particle result, a hood if the dust is overhead, and the respirator the exposure assessment calls for. The fire watch and the 35-foot rule in 1910.252(a)(2) apply to the people in the area whatever they are wearing.