1. (1) Where the current PM_2.5 is 20.5 µg/m³ (AQI 72) or more, the employer is encouraged to implement exposure controls.
2. (2) Where the current PM_2.5 is 35.5 µg/m³ (AQI 101) or more, the employer must implement effective exposure controls whenever feasible.

3. (3) Such controls include, but are not limited to:

   1. (a) Providing enclosed buildings, structures, or vehicles where the air is adequately filtered;
   2. (b) Providing portable HEPA filters in enclosed areas;
   3. (c) Relocating work to a location with a lower ambient air concentration of PM_2.5;
   4. (d) Changing work schedules to a time with a lower ambient air concentration of PM_2.5;
   5. (e) Avoiding or reducing work that creates additional exposures to dust, fumes, or smoke;
   6. (f) Reducing work intensity; and
   7. (g) Providing additional rest periods.

4. (4) WAC 296-820-835 is not required during emergency response.

   Note:

   Exposure controls may be implemented to the extent that the work is no longer covered by the scope of this rule as listed in WAC 296-820-805 (1) or (2).

[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, 49.17.060, and chapter 49.17 RCW. WSR 25-09-064, s 296-820-835, filed 4/15/25, effective 5/16/25; WSR 24-01-070, § 296-820-835, filed 12/14/23, effective 1/15/24.]