Wash. Admin. Code § 16-230-640
Use restricted herbicides shall not be applied on and after April 1st through October 31st of each year when there is a temperature inversion; or throughout the year if weather conditions are such that damage could result to adjacent and nearby towns, susceptible crops and plantings through physical drift or volatilization, or the temperature is 85°F. or above at the point of application: Provided, That application at the rate of fifty gallons or more per acre and conforming to the manufacturer's specified combination of nozzle type/size and pressure in pounds per square inch (psi) at the nozzle that produces a spray droplet size that falls within the very coarse (or larger) range as defined by the ASABE standards shall be exempt from the 85°F. temperature cutoff requirement: Provided further, That when using an invert system, applications may occur up to 95°F. with a maximum wind velocity of fifteen miles per hour and with water carrier at twelve or more gallons per acre.
Wash. Admin. Code § 16-230-640
Statutory Authority: Chapters 17.21, 15.58, and 34.05 RCW. 07-11-041A, § 16-230-640, filed 5/9/07, effective 6/9/07. Statutory Authority: Chapters 15.58 and 17.21 RCW. 88-05-033 (Order 1965), § 16-230-640, filed 2/12/88; 87-09-015 (Order 1923), § 16-230-640, filed 4/6/87; 80-03-041 (Order 1680), § 16-230-640, filed 2/20/80.