7.2 Signal Words, Precautionary Statements, and Toxicity Categories

Signal words are not slogans and they are not a chronic-toxicity ranking. Under 40 CFR 156.64, the signal word on the front panel is a code for the product’s highest acute Toxicity Category among the five routes in 40 CFR 156.62: oral, dermal, inhalation, eye irritation, and skin irritation. Category I is the highest (most acutely hazardous). The signal word must also appear with the heading for the human precautionary-statement section (40 CFR 156.70). The New Jersey Core tests this because 40 CFR 171.103(c)(1)(ii) requires you to understand instructions, warnings, terms, and symbols commonly appearing on labels — including DANGER, POISON, the skull and crossbones, WARNING, CAUTION, and the child-hazard warning.

The word reflects the product as sold or distributed, not the tank mix. 40 CFR 156.64(b)(2) forbids a signal word that reflects a lesser Toxicity Category associated with a diluted product. Precautionary statements for a use dilution may appear, but the front-panel signal word stays with the concentrate. The word also does not tell you whether EPA or New Jersey classified the product as restricted use, whether you need Core plus a category to apply it for hire, or whether NJDEP has registered it.

The four Toxicity Categories (40 CFR 156.62)

A Toxicity Category is assigned for each of five acute tests. The highest category (lowest number) among those routes sets the signal word.

Memorize the oral 50 / 500 / 5,000 breaks and the idea that Category I eyes or skin can be corrosive without the product being a systemic poison. That distinction drives the next rule.

Signal words, POISON, and the skull and crossbones

40 CFR 156.64(a) maps category to word:

This is the highest-yield Core distinction in the chapter. A fumigant or concentrate that can kill at a low oral or inhalation dose is DANGER–POISON with a skull and crossbones. A strongly corrosive herbicide that is Category I only for eye or skin irritation still says DANGER, but it does not get “Poison” in red or the skull unless a systemic route is also Category I. Treating every DANGER label as a poison, or assuming a DANGER product without a skull is “only CAUTION-level,” both fail the exam.

40 CFR 156.64(b) adds three prohibitions. A product may not bear a signal word for a higher category than its worst route unless EPA requires it to prevent unreasonable adverse effects. It may not bear a word for a lesser diluted category. It may not bear different signal words on different parts of the same label.

Child-hazard warning and first aid

40 CFR 156.66 requires “Keep Out of Reach of Children” on the front panel, on a separate line, close to the signal word if one is required. The statement is still required on Toxicity Category IV products that do not otherwise require a signal word. EPA may waive or substitute an alternative only in narrow cases (remote industrial exposure, a product approved for use on children such as a repellent, or an impregnated pet collar). “No signal word, so no child warning” is false. 40 CFR 171.103(c)(2) also lists keeping children from pesticides as a core safety competency; the front-panel sentence is the labeling hook.

40 CFR 156.68 requires a first aid (or “Statement of Practical Treatment”) statement if the product has systemic effects in Category I, II, or III, or skin or eye irritation in Category I or II. For any product assigned to Category I by any route, first aid must appear on the front panel, unless EPA allows a front-panel referral such as “See first aid statement on back panel.” Category II and III first aid may appear on any panel. Dilution first-aid language may augment concentrate first aid; it may not replace it, and it must be based on the highest use concentration the label allows.

Precautionary statements: human, environmental, physical

40 CFR 156.60 splits the job: hazard statements describe the type of harm; precautionary statements tell the user how to avoid or mitigate it. 40 CFR 156.70 groups human (and domestic-animal) statements under “Precautionary Statements,” immediately preceded by the signal word. Typical wording tracks category: Category I systemic products use “Fatal (poisonous) if swallowed [inhaled or absorbed through skin]” and “Do not breathe… Do not get in eyes, on skin, or on clothing.” Category II uses “May be fatal…” Category III uses “Harmful if…” Category IV generally requires no human-hazard precautionary statements from that table — which is not permission to skip PPE the Directions for Use or a New Jersey rule still require.

If the product is a sensitizer, there are no toxicity categories for sensitization; the typical statement is that prolonged or frequently repeated skin contact may cause allergic reactions in some individuals.

Environmental Hazards live in 40 CFR Part 156 Subpart E. Outdoor products with very high mammalian or avian acute toxicity may be required to say the pesticide is toxic (or extremely toxic) to wildlife; highly fish-toxic products must say they are toxic to fish. Foliar agricultural, forest, shade-tree, or mosquito products toxic to pollinators must bear appropriate cautions. A typical outdoor (non-aquatic) caution is “Keep out of lakes, ponds or streams. Do not contaminate water by cleaning of equipment or disposal of wastes.” Those sentences are mandatory when they appear as label directions, not optional conservation tips.

Physical or Chemical Hazards (40 CFR 156.78) cover flammability and explosion. Pressurized products use flash-point and flame-extension tests to choose Extremely flammable, Flammable, or a contents-under-pressure statement; non-pressurized products add Combustible between 80 °F and 150 °F flash point. Total-release foggers with a highly flammable propellant get extra “highly flammable ingredient” text, a fire graphic, and the 40 CFR 156.10(i)(2)(x)(D) fogger-use commands (one fogger per room, no small enclosed spaces, shut off ignition sources). Those fogger sentences are Directions for Use, not advice.

Handler personal protective equipment (PPE) statements for agricultural uses are specified in 40 CFR 156.212 and appear in the Hazards to Humans (and Domestic Animals) section as commands such as “Applicators and other handlers must wear…” If data for a route are missing and the signal word is CAUTION, 156.212(d)(2) treats that route as Category III for PPE minimums — another reason “CAUTION means no PPE” fails.

Spanish signal words on agricultural labels

For products that bear agricultural-use (WPS) labeling, 40 CFR 156.206(e) adds a language rule. Toxicity Category I and II products must show the signal word in Spanish next to the English word, plus: “Si Usted no entiende la etiqueta, busque a alguien para que se la explique a Usted en detalle. (If you do not understand the label, find some one to explain it to you in detail.)” Category I uses PELIGRO; Category II uses AVISO. That is labeling, not a courtesy translation. If a New Jersey farm crew cannot read the English DANGER panel, the certified applicator still has to make the mandatory instructions understood — 40 CFR 171.201 use-specific instructions must be in a language the noncertified person understands.

New Jersey overlay: the word does not replace the license

A CAUTION or no-signal-word Category IV product used for hire in New Jersey still requires a commercial applicator license (Core plus the matching N.J.A.C. 7:30-6.3 category) and, when the firm is in the business of applying pesticides, a business license. “It’s only CAUTION” is not a defense to unlicensed commercial application, skipped mandatory PPE, or holding a product that is not on NJDEP’s registered-product list. Signal word answers the acute-hazard question. Dual registration and category certification answer the legal-use question.

Worked New Jersey scenarios

Scenario D — corrosive DANGER without POISON. A Category 6A vegetation-management herbicide is Category I for eye corrosion and Category III orally. The front panel must say DANGER. It must not display red POISON or a skull and crossbones solely for that eye effect (156.64(a)(1)). The crew still follows every mandatory eye-protection statement.

Scenario E — Category IV and no signal word. A ready-to-use antimicrobial is Category IV by all five routes. EPA does not require a signal word. If marketing prints a word, it must be CAUTION. Keep Out of Reach of Children remains on the front panel. Mixing it at a school without the registered label on site still violates 7:30-10.2(i).

Scenario F — tank-mix “WARNING.” A DANGER concentrate is diluted to a field mix the applicator thinks is “only CAUTION strength.” The jug the mixer handles is still DANGER. 156.64(b)(2) forbids treating the concentrate as if it carried a lesser word. PPE and first aid for the concentrate apply at the mix site.