Wash. Admin. Code § 16-233-111 – Entry restrictions associated with pesticide applications—40 C.F.R., § 170.405

(1) Outdoor production pesticide applications.
1. (a) The application exclusion zone shall be as follows:
  1. (i) The application exclusion zone is the area that extends 100 feet horizontally from the point(s) of pesticide discharge from the application equipment in all directions during application when the pesticide is applied by any of the following methods:
    1. (A) Aerially.
    2. (B) Air blast or air-propelled applications.
    3. (C) As a fumigant, smoke, mist, or fog.
    4. (D) As a spray using nozzle configurations which produce a droplet size of smaller than medium, in accordance with the meaning given to "medium" in ANSI/ASAE S572, ANSI/ASAE S572.1, ANSI/ASAE S572.2, or ANSI/ASAE S572.3 (all incorporated by reference in subsection (3) of this section).
  2. (ii) The application exclusion zone is the area that extends 25 feet horizontally from the point(s) of pesticide discharge from the application equipment in all directions when the pesticide is sprayed from a height of greater than 12 inches from the soil surface or planting medium using nozzles or nozzle configurations which produce a droplet size of medium or larger, in accordance with the meaning given to "medium" in ANSI/ASAE S572, ANSI/ASAE S572.1, ANSI/ASAE S572.2, or ANSI/ASAE S572.3 (all incorporated by reference in subsection (3) of this section).
  3. (iii) There is no application exclusion zone when the pesticide is applied in a manner other than those covered in (a)(i) and (ii) of this subsection.
2. (b) During any outdoor production pesticide application, the agricultural employer must not allow or direct any worker or other person to enter or to remain in the treated area or an application exclusion zone (AEZ) that is within the boundaries of the establishment until the application is complete, except for:
  1. (i) Appropriately trained and equipped handlers involved in the application; and
  2. (ii) Owners of the agricultural establishment and their immediate family members who remain inside closed buildings, housing, or shelters under the conditions specified in WAC 16-233-301.
3. (c) After the application is complete, the area subject to the labeling-specified restricted-entry interval and the post-application entry restrictions specified in WAC 16-233-116 is the treated area.

(2) Enclosed space production pesticide applications.

(a) During any enclosed space production pesticide application described in column 1 of Table 1 under (d) of this subsection, the agricultural employer must not allow or direct any worker or other person, other than an appropriately trained and equipped handler involved in the application, to enter or to remain in the application exclusion zone (AEZ) area specified in column 2 of Table 1 under (d) of this subsection during the application and until the time specified in column 3 of Table 1 under (d) of this subsection has expired.
(b) After the time specified in column 3 of Table 1 under (d) of this subsection has expired, the area subject to the labeling-specified restricted-entry interval and the post-application entry restrictions specified in WAC 16-233-116 is the area specified in column 4 of Table 1 under (d) of this subsection.
(c) When column 3 of Table 1 under (d) of this subsection specifies that ventilation criteria must be met, ventilation must continue until the air concentration is measured to be equal to or less than the inhalation exposure level required by the labeling. If no inhalation exposure level is listed on the labeling, ventilation must continue until after one of the following conditions is met:
1. (i) Ten air exchanges are completed.
2. (ii) Two hours of ventilation using fans or other mechanical ventilating systems.
3. (iii) Four hours of ventilation using vents, windows, or other passive ventilation.
4. (iv) Eleven hours with no ventilation followed by one hour of mechanical ventilation.
5. (v) Eleven hours with no ventilation followed by two hours of passive ventilation.
6. (vi) Twenty-four hours with no ventilation.

(d) The following table applies to (a), (b), and (c) of this subsection.

Table 1

Entry Restrictions During Enclosed Space Production Pesticide Applications

1. When a pesticide is applied:	2. Prohibit workers and any persons, other than appropriately trained and equipped handlers, from being in AEZ:	3. Until:	4. After the expiration of time specified in column 3, the area subject to the restricted-entry interval is:
(a) As a fumigant	Entire enclosed space plus any adjacent structure or area that cannot be sealed off from the treated area	The ventilation criteria of subsection (2)(c) of this section are met	No post-application entry restrictions required by WAC 16-233-116 after criteria in column 3 are met
(b) As a(i) Smoke, or(ii) Mist, or(iii) Fog, or(iv) As a spray using a spray quality (droplet spectrum) of smaller than medium (volume median diameter of less than 294 microns)	Entire enclosed space	The ventilation criteria of subsection (2)(c) of this section are met	Entire enclosed space
(c) Not as in (a) or (b) above, the pesticide product label requires a respirator during application	Entire enclosed space	The ventilation criteria of subsection (2)(c) of this section are met	Treated area
(d) Not as in (a), (b) or (c) above, and:(i) From a height of greater than 12 inches from the planting medium, or(ii) As a spray using a spray quality (droplet spectrum) of medium or larger (volume median diameter of 294 microns or greater)	Treated area plus 25 feet in all directions of the treated area, but not outside the enclosed space	Application is complete	Treated area
(e) Otherwise	Treated area	Application is complete	Treated area

(3) Incorporation by reference. The material listed in this subsection (3) is incorporated by reference into this section.
1. (a) ANSI/ASAE S572 FEB2004, Spray Nozzle Classification by Droplet Spectra, reaffirmed February 2004 (ANSI/ASAE S572).
2. (b) ANSI/ASAE S572.1 MAR2009 (R2017), Spray Nozzle Classification by Droplet Spectra, reaffirmed December 2017 (ANSI/ASAE S572.1).
3. (c) ANSI/ASAE S572.2 JUL2018, Spray Nozzle Classification by Droplet Spectra, ANSI approved July 2018 (ANSI/ASAE S572.2).
4. (d) ANSI/ASAE S572.3, Spray Nozzle Classification by Droplet Spectra, ANSI approved February 2020 (ANSI/ASAE S572.3).

[Statutory Authority: RCW 17.21.030(2), 17.21.440, and 15.58.040(2). WSR 26-09-109, s 16-233-111, filed 4/21/26, effective 6/1/26. Statutory Authority: RCW 15.58.040 and 17.21.030. WSR 20-21-029, § 16-233-111, filed 10/12/20, effective 11/12/20. Statutory Authority: RCW 15.58.040, 17.21.030 and chapter 34.05 RCW. WSR 18-01-054, § 16-233-111, filed 12/13/17, effective 1/13/18.]