2.3 The Worker Protection Standard (WPS)

The Worker Protection Standard (WPS) is 40 CFR Part 170. ODAFF’s pesticide page describes it the same way EPA does: it is a federal regulation designed to protect agricultural workers (people employed in the production of agricultural plants) and pesticide handlers (people mixing, loading, or applying pesticides, or doing certain tasks involving direct contact with pesticides). It applies on agricultural establishments — farms, forests, nurseries, and greenhouses — when pesticides are used in the production of agricultural plants. It is not a second copy of the entire Oklahoma Combined Pesticide Law, and it is not a blanket rule for every spray job in the state.

Who WPS protects — and who it does not

Workers are employees doing tasks related to the production of agricultural plants on an agricultural establishment (hand weeding cotton, detasseling, harvesting produce, moving ornamental stock in a commercial greenhouse). Handlers mix, load, transfer, or apply pesticides; dispose of pesticides or containers; clean or repair application equipment; act as flaggers; or do other listed contact tasks, including certain crop-advisor tasks during an application or REI.

Typical urban structural work is not WPS. Treating a Tulsa apartment for cockroaches under Oklahoma 7A, pretreat a Midwest City house for termites under 7B, or fumigate a non-agricultural structure under 7C does not become a WPS job merely because a pesticide is involved. WPS attaches when the work is on an agricultural establishment as defined and the pesticide is used in production of agricultural plants. A commercial nursery or greenhouse producing plants is WPS territory. A sod farm producing sod is agricultural production. A custom applicator spraying wheat, cotton, or pasture for a grower is in WPS territory as a handler, and the grower who employs field workers is an agricultural employer. A municipal athletic turf that is not producing agricultural plants is generally outside Part 170 — the label and the Oklahoma turf category still apply.

If you hold 7A and you are hired to treat a farm shop on a Caddo County wheat operation, do not assume WPS vanished and do not assume WPS swallowed the whole farmstead. Apply the definition: production of agricultural plants on an agricultural establishment. Indoor structural pest control in a residence or office is still structural work. Outdoor production agriculture is WPS. When in doubt on a mixed site, follow the stricter applicable duty and get the current EPA WPS text rather than inventing a coverage rule.

Agricultural employer versus handler employer

Agricultural employer means a person who owns, or is responsible for the management or condition of, an agricultural establishment and who employs any worker or handler. Handler employer means a person who is self-employed as a handler or who employs any handler, including a commercial pesticide handling establishment that applies pesticides on farms for hire.

40 CFR 170.309 lists agricultural-employer duties. Among them: ensure each worker and handler receives WPS protections; ensure any handler and any early-entry worker is at least 18 years old; give supervisors, including labor contractors, enough information to protect workers and handlers; display pesticide safety information and pesticide application and hazard information as required by § 170.311; keep workers out of treated areas until application and hazard information is displayed and the restricted-entry interval has expired, except for the narrow early-entry provisions; and provide records to EPA or the state pesticide agency on request. ODAFF is that state agency in Oklahoma.

Handler employers have parallel, handler-focused duties. Before a handler performs a handler activity, the handler employer must ensure the handler has read the applicable labeling or has been informed, in a manner the handler can understand, of the labeling requirements for safe use; must ensure the handler has access to the labeling during the activity; and must ensure the handler is aware of entry restrictions, application exclusion zones, and restricted-entry intervals that apply to that activity. When a custom applicator sprays a Caddo County wheat field, both the grower (agricultural employer) and the custom business (handler employer) have WPS duties. “The other company was supposed to post” is not a defense.

Restricted-entry interval and early entry

The restricted-entry interval (REI) is the time immediately after an application when entry into the treated area is restricted. The REI is on the labeling. If two or more products are applied and they have different REIs, follow the longer REI. Workers must stay out during the REI except for the narrow early-entry exceptions in 40 CFR 170.603. Those exceptions are not a “just walk through, it has been an hour” rule. Early-entry workers must be at least 18, must be informed of the hazards, must receive labeling information related to human hazards and first aid, and must be provided the early-entry PPE the labeling requires. Agricultural employers may not send 16-year-old summer help into a cotton field that is still under REI to “move irrigation pipe for ten minutes.”

After the REI expires, WPS still requires that application and hazard information for that treated area be displayed before workers enter, and that treated-area warning signs be removed or covered when they are no longer required. REI is not the same as the Application Exclusion Zone. The REI is a clock on the treated area after the application. The AEZ is a moving zone around the equipment during the application.

Application Exclusion Zone

The Application Exclusion Zone (AEZ) is an area surrounding the outdoor application equipment’s point of pesticide discharge (for example, the boom nozzles). It exists only during the application, moves with the equipment, and can extend outside the agricultural establishment — onto a county road, a school ground, a neighbor’s pasture, or an easement. When the application ends, the AEZ ends. Post-application restrictions such as the REI then apply to the treated area.

Do not memorize a single AEZ distance as if every Oklahoma application used one number. 40 CFR 170.405 sets AEZ criteria by application method, droplet size, and related factors. The 2015 WPS used 25-foot and 100-foot radii. EPA’s 2024 AEZ reconsideration (final rule published October 4, 2024, effective December 3, 2024) restored 2015-style AEZ protections and again describes a 25-foot or 100-foot radius depending on application type and droplet size. Aerial applications, airblast, and fumigant/smoke/mist/fog applications have historically used the larger radius; certain ground sprays have used the smaller. Follow the current EPA WPS/AEZ text in 40 CFR 170.405 and the product labeling for the job in front of you. A wheat boom spraying medium droplets next to a farm lane is not automatically the same AEZ as an airblast spray in a pecan orchard or an aerial application over cotton.

Two duties are easy to reverse on an exam:

• The agricultural employer must not allow any worker or other person — other than appropriately trained and equipped handlers involved in the application — in an AEZ that is within the boundaries of the agricultural establishment. The employer may not send field workers to “keep picking on the other end of the boom.”
• The handler performing the application must immediately suspend the application if any worker or other person is in the AEZ, whether those people are on or off the establishment, including in an easement. The handler may not resume until people have left the AEZ. If people are in the AEZ on the neighbor’s pasture or along the section-line road, suspend.

EPA’s current AEZ guidance also describes a limited immediate-family exemption that can allow farm owners and their immediate family to remain inside enclosed structures during an application if stated conditions are met. That exemption does not apply to employees or labor housing. Do not park a crew in a bunkhouse inside the AEZ and call them family.

Pesticide safety training, central posting, and two-year records

Workers must be trained under 40 CFR 170.401 before they perform tasks in a treated area on an agricultural establishment where, within the last 30 days, a pesticide has been used or an REI has been in effect. The agricultural employer must ensure that training occurred within the last 12 months, unless an exception applies. Handlers must be trained under § 170.501 before performing any handler activity, again within the last 12 months unless excepted. A person who is currently certified as an applicator of restricted-use pesticides under 40 CFR Part 171 is excepted from that WPS training requirement. Certification is not an exception from the AEZ, the REI, labeling, or decontamination duties.

40 CFR 170.311 requires display of pesticide safety information and pesticide application and hazard information when workers or handlers are on the establishment and, within the last 30 days, a pesticide has been used or an REI has been in effect. Application and hazard information includes the Safety Data Sheet (SDS); the product name, EPA Registration Number, and active ingredients; the crop or site treated and the location of the treated area; the date(s) and times the application started and ended; and the duration of the REI. Display that information no later than 24 hours after the application ends, at a place workers and handlers are likely to pass, remaining legible and accessible during normal work hours. Keep it displayed until at least 30 days after the last applicable REI ends, or until workers or handlers are no longer on the establishment, whichever is earlier.

Record retention: whenever that application and hazard information is required to be displayed, the agricultural employer must retain it on the agricultural establishment for two years after the date of expiration of the restricted-entry interval applicable to that application (40 CFR 170.311(b)(6)). A designated representative may request that information in writing for applications made while the worker or handler was employed, going back as far as those two years.

Decontamination supplies and eyewash

40 CFR 170.411 requires agricultural employers to provide workers with decontamination supplies: water, soap, and single-use towels. Hand-sanitizing gels and wet towelettes do not replace soap or single-use towels. Supplies must be located together outside any treated area or REI, reasonably accessible, and generally not more than 1/4 mile from the workers (with a vehicular-access exception for remote work). Timing depends on the REI:

• If any pesticide with an REI greater than four hours was applied, provide supplies from the time workers first enter the treated area until at least 30 days after the REI expires.
• If the only pesticides applied in the treated area have REIs of four hours or less, provide supplies until at least seven days after the REI expires.

40 CFR 170.509 requires handler decontamination supplies at mixing sites and within about 1/4 mile of the handler activity (with a pilot exception: supplies in the aircraft or at the loading site). Emergency eye-flushing: whenever a handler is mixing or loading a product whose labeling requires protective eyewear, or is mixing or loading any pesticide using a closed system operating under pressure, the handler employer must provide, at each mixing/loading site immediately available to the handler, at least one system capable of delivering gently running water at a rate of at least 0.4 gallons per minute for at least 15 minutes, or at least six gallons of water in containers suitable for a gentle eye-flush for about 15 minutes. That is a handler-employer duty, not a “someone will bring a bottle later” hope.

Handler respirators

When the pesticide labeling requires a respirator, 40 CFR 170.507(b)(10) requires the handler employer to complete three steps before the handler performs any handler activity where the respirator must be worn:

1. Fit testing using the respirator specified on the labeling, in a manner that conforms to 29 CFR 1910.134
2. Training in use of that respirator, conforming to the OSHA respirator-training provisions referenced in the WPS
3. A medical evaluation by a physician or other licensed health care professional confirming the handler can safely wear that respirator

The handler employer must keep those records for two years on the establishment. A paper dust mask grabbed from a glove box does not satisfy a labeling statement that requires an NIOSH-approved respirator with a specified filter or cartridge. A Core certificate does not replace fit testing. If the wheat herbicide or cotton insecticide labeling requires a respirator for mixing, the custom-applicator employer in Oklahoma must run the medical-evaluation, fit-test, and training sequence before the mixer opens the jug.

Minimum age 18

Under WPS, handlers and early-entry workers must be at least 18 years old (40 CFR 170.309(c); the training content in § 170.401 also states that workers must be 18 to perform early-entry activities and that handlers must be at least 18). Members of the agricultural establishment owner’s immediate family are exempt from some WPS provisions, including some age provisions that apply to employees. Do not treat a hired 17-year-old neighbor as immediate family. Do not send a minor into a treated cotton field during an REI as “early entry.” Oklahoma commercial applicator certification itself also requires the applicant to be at least 18 under 40 CFR 171.103(a)(1); that certification-age rule is related but not a substitute for the WPS handler/early-entry age rule on the farm.

ODAFF enforcement and OSU education

ODAFF’s pesticide page links the Worker Protection Standard and points to both EPA WPS information and OSU Worker Protection Information. OSU Extension’s Pesticide Safety Education Program describes a coordinated approach: ODAFF inspects and enforces; facilities that are out of compliance may work toward compliance on their own or through an assistance program that uses OSU’s educational role. OSU personnel help greenhouses, nurseries, and farming facilities understand posting, training, decontamination, and AEZ duties. ODAFF remains the Oklahoma agency that enforces pesticide law. A training attendance sheet from an OSU WPS session is valuable evidence of education; it is not a shield against an ODAFF inspection finding that workers were in an AEZ or that SDS records were missing.

Exam traps for this section

• WPS is agricultural-establishment law, not a synonym for every Oklahoma pesticide job. 7A/7B urban structural work is generally outside Part 170.
• AEZ ≠ REI. One exists during the application around the equipment; the other is a clock on the treated area afterward.
• There is not one AEZ distance for every application. Current EPA text uses 25-foot or 100-foot radii depending on method and droplet size; read 40 CFR 170.405 and the label.
• Handlers suspend for people in the AEZ off the establishment, not only for people in the field being sprayed.
• Hand sanitizer is not soap for WPS decontamination.
• Part 171 certification excepts WPS training, not AEZ, REI, eyewash, or respirator clearance.
• SDS and application information stay two years after the REI expires.
• Age 18 applies to handlers and early-entry workers.