U159 RCRA waste code Flammable, toxic solvent from paints, glues & coatings.
- Free, no account
- Based on 40 CFR 261.33 and EPA guidance
- Nothing is stored
Find a federal hazardous waste code
U159, Methyl ethyl ketone (MEK).
U-listed waste
Methyl ethyl ketone (MEK)
U-list unused product.
ComplyOnSiteIs U159 hazardous waste?
Yes, when the listing applies. U159 covers unused methyl ethyl ketone (MEK) that is thrown away, including off-specification product and qualifying residues. It is a U-listed waste, not an acute P-listed one, so the listing depends on the product and how it is discarded, not on a TCLP result alone.
When it applies, U159 is nonacute hazardous waste. On a required hazardous waste manifest, put U159 in Item 13. For VSQG exemptions and empty-container rules and pharmaceutical containers, follow the linked guides.
What does U159 cover?
This covers unused methyl ethyl ketone (MEK) thrown away pure or technical grade, or in a formulation where it is the only active ingredient. Off-specification batches, residues in non-empty containers and spill cleanup residues of those products count too. Inactive ingredients don't stop it being the only active ingredient.
- CAS
- 78-93-3
- Table entries
- 2-Butanone (I,T); Methyl ethyl ketone (MEK) (I,T)
- Hazard codes in the record
- I (ignitable), T (toxic)
- Rule
- 40 CFR 261.33(f)
Is methyl ethyl ketone (MEK) waste always U159?
| Code | When it fits |
|---|---|
| U159 | The unused chemical is thrown away, pure or technical grade or as the sole active ingredient. Qualifying product residues count too. |
| D035 | The TCLP extract of the waste holds methyl ethyl ketone at 200 mg/L or more. The product listing may also apply. |
| F005 | It is spent after solvent use, or is a still bottom from recovery. The F005 blend conditions also apply. |
| Characteristic waste (D001–D043) | A used chemical or a different formulation meets a hazardous waste characteristic. Any process listings that apply need assessing too. |
A listed unused product can also exhibit a characteristic, so both rows can apply. Having this chemical in a manufacturing waste doesn't make the waste U159. What counts is the waste’s origin, formulation and use history. Mixing listed waste with solid waste, or treating it, generally doesn't remove the listing. That takes an applicable exclusion, exception or approved delisting. Using the chemical as an ingredient or reactant doesn't by itself make it a spent F-listed solvent. Each listing has its own before-use blend conditions.
Which wastes take U159?
| Waste | When it’s U159 |
|---|---|
| Paint thinner | Unused thinner is thrown away as a qualifying commercial chemical product with methyl ethyl ketone (MEK) as the sole active ingredient |
| Solvent-contaminated wipes | Wipes hold unused methyl ethyl ketone (MEK) that meets U159 |
| Unused methyl ethyl ketone | Pure or technical-grade methyl ethyl ketone (MEK) is thrown away, or a product has it as the sole active ingredient |
Which codes sit beside U159?
| Code | What it is |
|---|---|
| U155 | Methapyrilene |
| U156 | Methyl chlorocarbonate |
| U157 | 3-Methylcholanthrene |
| U158 | 4,4′-Methylenebis(2-chloroaniline) |
| U160 | Methyl ethyl ketone peroxide |
| U161 | Methyl isobutyl ketone |
| U162 | Methyl methacrylate |
| U163 | MNNG |
Sources
- 40 CFR 261.33 — Discarded commercial chemical products, off-specification species, container residues, and spill residues thereof
- 40 CFR 261.3 — Definition of hazardous waste
- 40 CFR 261.7 — Residues of hazardous waste in empty containers
- 40 CFR 260.10 — Definitions
- 40 CFR 262.14 — Conditions for exemption for a very small quantity generator
- 40 CFR 262.20 — General requirements
- 40 CFR 266.507 — Residues of hazardous waste pharmaceuticals in empty containers
- Hazardous Waste Manifest Instructions
- 40 CFR 261.31 — Hazardous wastes from non-specific sources
- 40 CFR 261.24 — Toxicity characteristic