PDFWAC 296-45-45520
Backpack power units for use in pruning and clearing.
(1) While a backpack power unit is running, no one other than the operator may be within 10 feet (305 cm) of the cutting head of a brush saw.
(2) A backpack power unit must be equipped with a quick shutoff switch readily accessible to the operator.
(3) Backpack power unit engines must be stopped for all cleaning, refueling, adjustments, and repairs to the saw or motor, except as the manufacturer's servicing procedures require otherwise.