The other four

Washer concentrate, and methanol

Updated October 2026

On this page8

The rule Concentrate is nowhere near the line Ready-to-use dilutions still need checking Why methanol gets the lowest number The spray exemption, and what it means here Methanol and plastics A small bottle is not a safer bottle References

Four percent by weight. The lowest trigger in 1700.14, and this product clears it many times over.

The rule

Household substances in liquid form containing 4 percent or more by weight of methyl alcohol, other than those in pressurized spray containers, shall be packaged in accordance with 1700.15(a) and (b). There is no viscosity test and no further qualification.

Concentrate is nowhere near the line

Windshield washer concentrate is largely methanol, which is the point of it: a low freezing point in a small volume. So this is not a threshold to compute, it is a requirement to plan for.

Ready-to-use dilutions still need checking

A premixed washer fluid can sit either side of 4 percent depending on the temperature rating it is sold at. That one is genuine arithmetic, and the answer differs between a summer and a winter blend.

Why methanol gets the lowest number

Death and blindness can result from ingestion, which is why 1500.14 also singles it out for specific label statements at the same 4 percent. The regulators treated this as unusually serious and set the trigger accordingly.

The spray exemption, and what it means here

The methanol paragraph excludes products packaged in pressurized spray containers. A screw-capped jug of concentrate is not one, so the exemption does not reach the format this shelf is built for.

Methanol and plastics

HDPE handles it, which is why every container on this shelf is HDPE and why that is a sensible default rather than a cost decision. The liner is the part worth checking against the specific blend.

A small bottle is not a safer bottle

The threshold is a percentage, not a quantity, so a 250 mL concentrate is caught on exactly the same terms as a gallon. Size changes the freight and nothing about the packaging obligation.

References

16 CFR 1700.14, Substances requiring special packaging. Paragraph (a)(8) covers methanol at 4 percent or more by weight; (a)(11) ethylene glycol at 10 percent or more; (a)(31) nonemulsion liquid household chemical products at 10 percent or more hydrocarbons by weight under 100 SUS at 100 F. law.cornell.edu

16 CFR 1500.14, Products requiring special labeling. Paragraph (b)(2) requires "warning" and "Harmful or fatal if swallowed" for 10 percent or more ethylene glycol; (b)(3)(ii) requires "danger", "Harmful or fatal if swallowed" and "Call physician immediately" for 10 percent or more petroleum distillates, because they may be aspirated into the lungs. law.cornell.edu

Written from federal regulation and from measured catalog data, not from a blending bench. We sell containers and closures; whether a particular closure satisfies a particular clause is a question about that closure and its supplier’s testing, and nothing here certifies a package as compliant. Anything on these pages is a starting point.