One of the quandaries I find with the “Safe HW Area” approach is those areas that are actually set up as weld shops with all the bells and whistles we want in welding shops, such as ventilation to control exposures resulting from welding, cutting, and grinding. For example…
1910.252(a)(2)(viii) Ducts, requires that any ducts and/or conveyor systems that might carry sparks to distant combustibles shall be suitably protected or shut down within the 35′ fire safe area so as to NOT spread the ignition sources outside of our fire safe area.
But if we have a weld shop, these shops are typically equipped with ventilation to control the fumes/smoke/vapors from welding. The KEY here is that these ventilation systems are…
they are DESIGNED SOLELY for this purpose and are NOT part of a different ventilation system with other containment and, more importantly, NO COTTEN SOCKS or COMBUSTIBLE DUSTS!
.252(a)(2)(viii) Ducts exist for sound reasons… suck up a spark/ember/slag and send it traveling down ductwork at a high rate of speed, keeping it glowing hot when it reaches the cotton dust collector bags we will have a serious fire or even an explosion if the dust collector handles combustible dust.
So, our weld shop ventilation MUST be specifically designed and CONTAINED within its OWN system.