Under the Federal Hazardous Substances Act (FHSA), a household cleaner, paint, solvent, or other hazardous substance must carry a label with a signal word (DANGER, WARNING, or CAUTION), a statement of the principal hazard, the hazardous ingredient’s name, precautionary measures, first-aid instructions when needed, “Keep out of the reach of children” or its practical equivalent, and the name and place of business of the manufacturer, packer, distributor, or seller. CPSC’s rule at 16 CFR 1500.121 then sets where those statements go and how large they must print; 16 CFR 1500.14 adds fixed wording for listed products such as methanol, turpentine, antifreeze, charcoal, fireworks, and art materials.
This guide maps those sections (current eCFR text, up to date as of 2026-10-07; data checked 2026-10-10) onto the products an Amazon seller lists. It gives the tests and tables; it does not decide whether a specific product is a hazardous substance or what its label must say.
Does Your Product Fall Under the FHSA?
The labeling duty applies to a “hazardous substance” that is “intended, or packaged in a form suitable, for use in the household or by children” (16 CFR 1500.3(b)(14)). Two tests stack.
Test 1: is it a hazardous substance? Section 1500.3(b)(4)(i)(A) covers any substance or mixture “which is toxic, corrosive, an irritant, a strong sensitizer, flammable or combustible, or generates pressure through decomposition, heat, or other means,” if it “may cause substantial personal injury or substantial illness during or as a proximate result of any customary or reasonably foreseeable handling or use, including reasonably foreseeable ingestion by children.” The flammability bands are numeric: extremely flammable means a flashpoint at or below 20 °F, flammable above 20 °F and below 100 °F, and combustible at or above 100 °F to and including 150 °F (1500.3(c)(6)).
Test 2: is it for household use? Section 1500.3(c)(10)(i) reaches anything that “under any customary or reasonably foreseeable condition of purchase, storage, or use may be brought into or around a house,” including garages and sheds. It names polishes and cleaners “designed primarily for professional use but which are available in retail stores,” and car products such as antifreeze. It also says “Size of unit or container is not the only index.” An article “labeled as, and marketed solely for, industrial use” does not become subject to the Act just because a worker might take some home.
So a “professional grade” claim does not take a product out of scope if consumers can buy it from a retail listing.
What the definition excludes. Section 1500.3(b)(4)(ii) carves out pesticides under FIFRA, foods, drugs, and cosmetics under the FD&C Act, and household heating or cooking fuels stored in their system containers. Pest claims follow EPA rules (see our EPA pesticide devices guide) and cosmetics follow FDA rules (MoCRA for Amazon sellers). CPSC summarizes the scope on its FHSA requirements page.
The Required Label Elements at a Glance
Section 1500.3(b)(14)(i) lists what the label must state “conspicuously.” The table restates it in seller terms.
| # | Element | What the rule says |
|---|---|---|
| A | Name and place of business | Of the manufacturer, packer, distributor, or seller |
| B | Hazardous ingredient name | Common, usual, or chemical name of each component that “contributes substantially to its hazard” |
| C/D | Signal word | DANGER for extremely flammable, corrosive, or highly toxic; WARNING or CAUTION for all others |
| E | Statement of principal hazard | Such as “Flammable,” “Combustible,” “Vapor Harmful,” “Causes Burns” |
| F | Precautionary measures | Action to follow or avoid |
| G | First aid | “When necessary or appropriate” |
| H | The word Poison | For “highly toxic” substances, plus skull and crossbones (1500.121(b)(5)) |
| I | Handling and storage | For packages needing special care |
| J | Children | “Keep out of the reach of children” or its practical equivalent |
Under 1500.127, a product with more than one hazard, such as toxic and flammable, needs a hazard statement, precautions, and first aid for each one; combined wording is allowed only if it still covers every hazard. Under 1500.122, words that negate the warnings defeat the label; the rule’s examples are “Harmless” or “Safe around pets” on a toxic or irritant substance.
Choosing the Signal Word: DANGER, WARNING, CAUTION, or POISON
The signal word follows the hazard class, not the seller’s preference.
| Hazard class (16 CFR 1500.3) | Signal word | Extra marks |
|---|---|---|
| Extremely flammable, corrosive, or highly toxic | DANGER | Highly toxic also needs “poison” and the skull and crossbones |
| All other hazardous substances | WARNING or CAUTION | None by default |
| Listed caustics at set strengths (1500.129) | POISON instead of any signal word | Printed in capitals on the principal display panel |
| Pressure is the only hazard (1500.130) | WARNING (CAUTION may substitute) | Fixed “contents under pressure” text |
The 1500.129 list matters for cleaning products. It includes hydrochloric acid, sulfuric acid, and sodium hydroxide (lye) at 10 percent or more, ammonia at 5 percent or more, and acetic acid at 20 percent or more, among others. For these, the rule says “the word ‘poison’ is necessary instead of any signal word.”
For aerosols whose only hazard is pressure, 1500.130(b) supplies an accepted statement: “Do not puncture or incinerate container. Do not expose to heat or store at temperatures above 120 °F. Keep out of the reach of children.” Added hazards, such as flammability, need more labeling (1500.130(d)).
Placement: The Principal Display Panel and the Boxed Warning
Section 1500.121 states: “Labels that do not comply with this regulation may be considered misbranded.” The principal display panel is the part of the package “designed to be most prominently displayed, shown, presented, or examined under conditions of retail sale.” On it:
- Boxed core warning. The signal word, the hazard statement, and any instruction to read cautions elsewhere “shall be blocked together within a square or rectangular area, with or without a border” (1500.121(b)(2)(ii)). A border line or blank space must separate them from other printed matter.
- Everything else together. Cautionary items not on the front “shall be placed together on a display panel elsewhere,” and the front then carries “Read carefully other cautions on the ___ panel,” or its practical equivalent (1500.121(b)(3)).
- Removable lids. If the front panel is a cap or lid that can be discarded, the container is treated as having a second principal display panel that needs the signal word and hazard statement (1500.121(b)(2)(iii)(A)).
- Outer packaging. Warnings on the immediate container must also appear on any outer carton used in retail display, unless they are clearly legible through it (1500.121(b)(4)).
Style rules sit in 1500.121(c) and (d). Signal words and hazard statements “shall be in capital letters”; capital letters can be no more than 3 times as tall as wide; and contrast must be sharp. Combinations that may fail include “black letters on a dark blue or dark green background” and “white letters on a light gray or tan background.”
Type Size: Table I in 16 CFR 1500.121
Minimum type size is the printed height of a capital letter, keyed to the area of the panel. Values below are from Table I (current eCFR text, up to date as of 2026-10-07; data checked 2026-10-10).
| Principal display panel area (sq in) | 0-2 | >2-5 | >5-10 | >10-15 | >15-30 | >30 |
|---|---|---|---|---|---|---|
| Signal word (inch) | 3/64 | 1/16 | 3/32 | 7/64 | 1/8 | 5/32 |
| Statement of hazard (inch) | 3/64 | 3/64 | 1/16 | 3/32 | 3/32 | 7/64 |
| Other cautionary material (inch) | 1/32 | 3/64 | 1/16 | 1/16 | 5/64 | 3/32 |
How to measure the area (1500.121(c)(1)):
- Rectangular box: height times width of the whole front side.
- Bottle or cylinder: 40 percent of height times circumference, excluding necks, shoulders, and flanges.
- Other shapes: 40 percent of total surface, or the obvious panel if there is one.
Two worked examples, assuming these dimensions. A box front 3 inches wide by 5 inches tall is 15 square inches, so the signal word needs at least 7/64 inch, the hazard statement 3/32 inch, and other cautions 1/16 inch. A bottle with a 6-inch label height and 8-inch circumference counts as 19.2 square inches, which moves it to the >15-30 column: 1/8, 3/32, and 5/64 inch.
Back-panel cautions are sized by that panel’s own area (1500.121(c)(2)(iii)). Product-specific rules can override Table I; charcoal is one.
Products With Specific Wording Under 16 CFR 1500.14
For the substances in 1500.14(b), CPSC found the general label “not adequate” and prescribed added statements. If your formula crosses these thresholds, the wording is set.
| Substance and threshold | Signal word | Required statements (summary of 1500.14(b)) |
|---|---|---|
| Diethylene glycol, 10% or more | WARNING | “Harmful if swallowed” |
| Ethylene glycol (antifreeze), 10% or more | WARNING | “Harmful or fatal if swallowed” |
| Benzene, 5% or more | DANGER | “Vapor harmful,” the word poison, skull and crossbones; at 10% or more add “Harmful or fatal if swallowed” and “Call physician immediately” |
| Toluene, xylene, or petroleum distillates (kerosine, mineral spirits, naphtha, and similar), 10% or more | DANGER | “Harmful or fatal if swallowed,” “Call physician immediately”; toluene and xylene also “Vapor harmful” |
| Methanol, 4% or more | DANGER | Poison, skull and crossbones, “Vapor harmful,” “May be fatal or cause blindness if swallowed,” “Cannot be made nonpoisonous” |
| Turpentine, 10% or more | DANGER | “Harmful or fatal if swallowed” |
| Charcoal for cooking or heating | WARNING | Fixed carbon monoxide label “within a heavy borderline,” upper 25% of front and back panels |
| Fireworks devices | Varies by device | Device-specific statements listed in 1500.14(b)(7) |
| Art materials | WARNING if only a chronic hazard exists | Toxicologist review and ASTM D-4236 conformance statement |
These sections are detailed. For charcoal bags packaged on or after November 3, 1997, “WARNING” must be in bold capitals at least 9/32 inch tall and the label at least 2 inches high (1500.14(b)(6)(ii)). For art materials, a toxicologist reviews the formula at least every 5 years, and containers over one fluid ounce or one ounce net weight need full precautionary labeling (1500.14(b)(8)). Fireworks statements and the contact adhesive rule (1500.133) are not reproduced here; read those sections directly.
Where This Meets an Amazon Listing
The FHSA rules above govern the physical label, outer packaging, and “accompanying literature.” They do not set the text of an Amazon detail page. Where they touch Amazon selling:
- Inserts and how-to cards. Under 1500.125, any placard, pamphlet, or other material with directions for use “shall bear all the information required by section 2(p) of the act.” A how-to card in the box with directions for use needs the cautions too.
- Name on the label. Element A allows the seller’s name, so a private-label seller controls this field.
- Bundles and outer boxes. Retail outer packaging must repeat the immediate container’s warnings unless they read through it (1500.121(b)(4)).
- Claims printed on the package. “Non-toxic” or “pet safe” on a product that is toxic or irritant runs into 1500.122 if it appears on the label or literature.
- Responsibility. Section 1500.210 applies the rules to “the causing of such act to be done,” and 1500.211 to 1500.212 cover guaranties from suppliers.
Amazon’s own dangerous goods review is a separate process with its own documents; see our Amazon hazmat review guide. Liquids also have prep rules in FBA prep requirements. If a labeling defect turns into a safety problem, see CPSC Section 15(b) reporting and Amazon product recalls. Amazon’s document requests arrive through Manage Your Compliance; see also product liability insurance.
Checklist: FHSA Cautionary Labeling Before You List
- Confirm the product is not a pesticide, food, drug, cosmetic, or system fuel, all of which follow other rules.
- Get the formula and SDS from your supplier and check each hazard class.
- Check 1500.129 and 1500.14(b) concentration thresholds before choosing the signal word.
- Draft all elements A through J, with a hazard statement and precautions for every hazard.
- Box the signal word and hazard statement on each principal display panel; add “Read carefully other cautions on the ___ panel” if cautions sit elsewhere.
- Measure the panel area and check Table I sizes, capitals, and contrast.
- Repeat the warnings on outer retail packaging and on any insert with directions for use.
- Remove “harmless,” “safe around pets,” or similar disclaimers from the label and inserts.
- Keep the dated label proof and supplier guaranty with your compliance files.
Frequently Asked Questions
Does every household cleaner need a DANGER, WARNING, or CAUTION label?
Only if it meets the hazardous substance definition in 16 CFR 1500.3, which turns on whether foreseeable handling or use may cause substantial injury or illness. If it qualifies, a signal word is required.
Is “Keep out of the reach of children” required word for word?
No. Section 1500.3(b)(14)(i)(J) allows “Keep out of the reach of children” “or its practical equivalent.” For an article intended for use by children that is not banned, the rule calls instead for “adequate directions for the protection of children from the hazard.”
Can CPSC review my label before I print it?
Section 1500.128 says the Commission “will offer informal comment on any proposed label” if you send the complete labeling, the full quantitative formula, the toxicity and chemical data, and any injury information.
Bottom Line
FHSA labeling comes down to three questions: is the product a household hazardous substance, which signal word and statements does its formula trigger, and does the layout meet 1500.121’s box, panel, and type-size rules. Settle the formula with your supplier, check 1500.14 and 1500.129, then size the label against Table I.