Wash. Admin. Code § 296-24-71509
In confined spaces, you must perform welding or cutting involving fluxes, coverings, or other materials which contain fluorine compounds in accordance with WAC 296-24-71507(1) through (5). A fluorine compound is one that contains fluorine, as an element in chemical combination, not as a free gas.
Note: Maximum allowable concentration. The need for local exhaust ventilation or airline respirators for welding or cutting in other than confined spaces will depend upon the individual circumstances. However, experience has shown such protection to be desirable for fixed-location production welding and for all production welding on stainless steels. Where air samples taken at the welding location indicate that the fluorides liberated are below the maximum allowable concentration, such protection is not necessary.
Wash. Admin. Code § 296-24-71509
Order 73-5, § 296-24-71509, filed 5/9/73 and Order 73-4, § 296-24-71509, filed 5/7/73.