Does Laundry Detergent Cause Cancer? The Truth About 1,4-Dioxane
The manufacturing byproduct behind the question, each agency's exact classification words, where exposure is documented, and the 1 ppm law now in force.
Green Llama's answer to does laundry detergent cause cancer is no, and the chemical behind the question is 1,4-dioxane, a manufacturing byproduct. No health agency lists detergent as a cause of cancer, and EPA's exact words for 1,4-dioxane are "likely to be carcinogenic to humans," not "known." EPA's November 2024 evaluation put the documented public risk in contaminated drinking water rather than in washing clothes. This page keeps hazard, exposure, and risk apart, and every claim carries a named source you can open.
Green Llama sells fragrance-free laundry powder, and we say so up front. An earlier version of this page called 1,4-dioxane a "known carcinogen." No agency uses that phrase, so that wording is corrected here, along with a New York limit given as 2 parts per million and a surfactant our current powders do not use, all three checked on August 14, 2026. Kay Baker, MS, OTR/L, Green Llama's CEO and Co-Founder, is the named author. Matthew Keasey, Ph.D., Co-Founder and CSO, has not yet completed his scientific review, and every chemistry and health claim here is flagged for it.
EWG Verified™ Max Strength Fragrance-Free Laundry Powder is listed at $19.95 for a 60-load pouch, one tablespoon per load. Its ingredient list names two surfactants, and neither carries an ethoxylation marker, the label signal for the process that creates 1,4-dioxane.
Check price & availability →What 1,4-Dioxane Is and How It Gets Into Detergent
1,4-Dioxane is a synthetic solvent that shows up in some cleaning products as a manufacturing leftover, not as an ingredient anyone added. The FDA, which tracks the same contaminant in cosmetics, explains that it "forms as a byproduct during the manufacturing process." The agency says the ingredients involved are "identifiable by the prefix, word, or syllables 'PEG,' 'Polyethylene,' 'Polyethylene glycol,' 'Polyoxyethylene,' '-eth-,' or '-oxynol-.'" It is not dioxin, either; EPA's consumer summary states "they are not the same."
The chemistry runs through ethoxylation. Manufacturers react raw surfactants with ethylene oxide to make them milder and foamier. The National Toxicology Program lists ethylene oxide itself as "known to be a human carcinogen," from studies of exposed workers. The finished detergent contains none of the gas; what the reaction can leave behind is 1,4-dioxane, formed when two ethylene oxide molecules join. The same program names the products where this happens:
"1,4-Dioxane may be formed as a by-product of reactions based on condensing ethylene oxide or ethylene glycol during manufacture of detergents, shampoos, surfactants, some food additives (polysorbate 60 and polysorbate 80), and certain pharmaceuticals."
National Toxicology Program, Report on Carcinogens, 15th EditionBecause it is a byproduct, it never appears on a label. In the words of New York's Department of Environmental Conservation: "1,4-dioxane is not listed as an ingredient in products because it is a manufacturing byproduct, not an intentionally added ingredient." The FDA has recommended "vacuum stripping" to manufacturers since the 1980s. Green Llama takes the other route: skip ethoxylated ingredients, and the byproduct has no way to form.
Hazard: What Each Agency Says, In Its Exact Words
Short answer: three scientific bodies have classified 1,4-dioxane, and none of them calls it a known human carcinogen.
| Body | Exact classification | Where and when | Evidence behind it |
|---|---|---|---|
| U.S. EPA (IRIS) | "Likely to be carcinogenic to humans" | IRIS assessment, 2010, updated 2013 | Inadequate evidence in humans; sufficient evidence in animals (liver tumors in rats, mice, and gallbladder cancer in guinea pigs) |
| National Toxicology Program | "Reasonably anticipated to be a human carcinogen" | Report on Carcinogens, first listed 1981 | "Sufficient evidence of carcinogenicity from studies in experimental animals" |
| IARC (WHO) | "Possibly carcinogenic to humans (Group 2B)" | Monographs Vol. 71, 1999 | "Inadequate evidence in humans"; "sufficient evidence in experimental animals" |
The animal evidence is real. In lifetime studies, rats, mice, and guinea pigs given 1,4-dioxane in drinking water developed liver tumors, and rats developed nasal-cavity cancer, per the National Toxicology Program profile. Those were high doses fed for most of the animals' lives. On the human side, the same profile reports that "the data available from epidemiological studies are inadequate to evaluate the relationship between human cancer and exposure specifically to 1,4-dioxane." ATSDR adds the noncancer picture in its own words: "exposure to very high levels of 1,4-dioxane can result in liver and kidney damage and death."
One more correction matters. EPA's 1988 assessment did say "probable human carcinogen" under guidelines retired years ago; the 2010 assessment replaced it. Pages still quoting "probable," including an older Green Llama article now flagged for cleanup, are quoting a classification that no longer exists. Every classification above is the agency's current text, checked by the author, Kay Baker, MS, OTR/L.
Exposure: How 1,4-Dioxane Reaches People (Washing Clothes Is Not the Main Path)
EPA answered that question for laundry detergent by name. Its November 2024 evaluation looked at "surface cleaner, dish soap, dishwasher detergent, laundry detergent" as products "likely to be used on a regular basis." It modeled chronic skin contact and inhalation, and concluded that "exposures to consumers and bystanders resulting from consumer use of products that contain 1,4-dioxane do not significantly contribute to the unreasonable risk." Skin contact adds little, for a reason FDA documented in cosmetics research on leave-on lotions. Those studies found 1,4-dioxane can penetrate skin. Further FDA work found it "evaporates readily, further diminishing the already small amount available for skin absorption, even in products that remain on the skin for hours." ATSDR's verdict on ordinary life: "the general population is exposed to negligible levels of 1,4-dioxane."
The documented problem sits down the drain. EPA did determine, as a whole-chemical matter, that "1,4-dioxane presents an unreasonable risk of injury to health." The drivers are workers who handle it in industrial settings, and drinking water. Detergent still matters on that second path, and not through your washing machine:
- Drinking water: EPA states 1,4-dioxane "is not removed through typical water treatment techniques and has been found in the drinking water of some U.S. communities." A 2017 analysis of EPA's national monitoring data found it in 21% of 4,864 public water systems
- Down-the-drain releases: per EPA, contamination "in commercial and consumer products like dish soaps and laundry detergents also significantly contributes to the unreasonable risk determination when these products are washed down the drain and contaminate surface water that is used as a source for drinking water"
- Workplaces that make or use it, per EPA's worker findings
- Using detergent at home: EPA's modeled consumer exposures stayed below its risk benchmarks
- Skin contact: FDA found penetration possible in lotions, but evaporation limits how much absorbs
- Worn laundry: no published measurement of residue transfer from washed fabric exists
Choosing a detergent with no 1,4-dioxane pathway is less about your own skin and more about what your household sends into the water everyone shares. That reasoning drives New York's law, and it drives Green Llama's formulation choice.
New York's 1 ppm Limit: What the Law Says Now
Short answer: since December 31, 2023, household cleansing products sold in New York may not contain more than 1 part per million of 1,4-dioxane. It is a concentration limit, not a product ban, and it is the first of its kind in the nation per the state's environmental agency.
"No household cleansing product shall be distributed, sold, offered or exposed for sale in this state which contains 1,4-dioxane other than such trace concentrations; such trace concentrations shall not exceed two parts per million by December thirty-first, two thousand twenty-two; and further, shall not exceed one part per million by December thirty-first, two thousand twenty-three."
New York Environmental Conservation Law § 35-0105(4)Laundry detergent sits inside that rule by definition, since the statute covers any surfactant-based product used for "the cleansing of fabrics."
Senate Bill S4389-B (Chapter 613 of 2019) amended the state's Environmental Conservation Law to cap 1,4-dioxane in household cleansing, personal care, and cosmetic products.
First 2 ppm, then today's 1 ppm for household cleansing and personal care products, with 10 ppm for cosmetics. Struggling manufacturers could buy time with one-year waivers; per the DEC, none remains effective after December 30, 2025.
The DEC adopted implementing regulations on September 18, 2024, calling New York "the first state in the nation" to regulate 1,4-dioxane in these categories. Its 2025 statutory review found the limits "sufficiently protective of human health and the environment."
New York did not ban any detergent: products reformulated and stayed on shelves. And since brands tend not to make a separate formula for one state, the limit reaches Green Llama readers everywhere.
How to Read a Label for Ethoxylation Red Flags
The contaminant itself never shows up on a label, so you look instead for the ingredients that signal the process which creates it. The FDA and New York's DEC publish overlapping lists, combined here.
- "PEG" followed by a number, and anything with "polyethylene glycol" or "polyoxyethylene" (FDA's list)
- Ingredients ending in "-eth": sodium laureth sulfate, ceteareth, oleth (FDA and DEC both name these)
- "Polysorbate" with a number, such as polysorbate 60 or 80 (named by the National Toxicology Program)
- Ingredients containing "xynol" (DEC's list)
- That the product contains 1,4-dioxane. DEC's own caution: "Just because a product contains one of these ingredients does not mean that product contains 1,4-dioxane. A product needs to be tested to determine if it contains 1,4-dioxane."
- That the byproduct survived manufacturing: vacuum stripping can remove most of it from a well-made ethoxylated ingredient
- That a clean label equals a tested bottle: a clean label means the formation pathway is absent, not that anyone tested your specific bottle
That caution cuts both ways. A "laureth" on the label raises the odds of trace contamination; it proves nothing about the bottle in your hand. Run the check on our own Max Strength laundry powder label; the full list sits in the open on its page. For every other name on a detergent label, Green Llama keeps a laundry detergent ingredients glossary and an ingredient-by-ingredient safety guide. Author Kay Baker, MS, OTR/L, applies the same sourcing rule to every name on those lists.
Does Green Llama's Laundry Powder Contain 1,4-Dioxane?
Green Llama's Max Strength powder has no ethoxylated ingredient, the only route by which 1,4-dioxane enters a detergent. Here is the formula, and what we will not claim about it.
The Max Strength Fragrance-Free Laundry Powder lists every ingredient on its page: decyl glucoside, protease and amylase enzymes, sodium carbonate, sodium citrate, sodium gluconate, sodium lauryl sulfoacetate, sodium metasilicate, sodium percarbonate, sodium polyaspartate, and TAED. Check it against the red flags above: no PEG, no polysorbate, nothing ending in "-eth" or containing "xynol." Both surfactants, decyl glucoside and sodium lauryl sulfoacetate, carry none of the ethoxylation markers the FDA and New York's DEC publish. And the formation route the National Toxicology Program describes needs ethylene oxide or ethylene glycol in the reaction. On that evidence the formula gives 1,4-dioxane no route to form, a claim read off the ingredient list rather than off a test result.
Beyond our own shelf, Green Llama's ingredient-tested detergent comparison applies these red-flag checks across brands. Our eco-friendly detergent standards guide covers the certifications, and our primer on what non-toxic laundry detergent means defines the vocabulary. Kay Baker, MS, OTR/L, is accountable for these product claims as the author, under the rule the rest of this page follows: a named source you can open.
Green Llama Max Strength Laundry Powder
EWG Verified and fragrance-free. Max-strength enzyme formula that lifts tough stains while staying gentle on skin. 60 loads per pouch, one tablespoon per load. Compostable packaging.
Frequently Asked Questions
Sources Cited
1. U.S. Environmental Protection Agency. (2013). 1,4-Dioxane (CASRN 123-91-1): IRIS chemical assessment summary. EPA Integrated Risk Information System.
2. U.S. Environmental Protection Agency. (2024, November). Unreasonable risk determination for 1,4-dioxane, CASRN 123-91-1. EPA Office of Chemical Safety and Pollution Prevention.
3. U.S. Environmental Protection Agency. (2024, November). Nontechnical summary of the TSCA risk evaluation for 1,4-dioxane (EPA-740-S-24-005).
4. U.S. Environmental Protection Agency. (n.d.). Final risk evaluation for 1,4-dioxane. Assessing and Managing Chemicals under TSCA.
5. U.S. Environmental Protection Agency. (n.d.). Risk management for 1,4-dioxane. Assessing and Managing Chemicals under TSCA.
6. National Toxicology Program. (2021). 1,4-Dioxane. Report on Carcinogens, Fifteenth Edition. U.S. Department of Health and Human Services.
7. National Toxicology Program. (2021). Ethylene oxide. Report on Carcinogens, Fifteenth Edition. U.S. Department of Health and Human Services.
8. International Agency for Research on Cancer. (1999). 1,4-Dioxane. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 71. Summary via WHO IPCS INCHEM.
9. Agency for Toxic Substances and Disease Registry. (2012). ToxFAQs for 1,4-dioxane (CAS # 123-91-1). U.S. Department of Health and Human Services.
10. Agency for Toxic Substances and Disease Registry. (2012). Toxicological profile for 1,4-dioxane. U.S. Department of Health and Human Services.
11. U.S. Food and Drug Administration. (n.d.). 1,4-Dioxane in cosmetics: A manufacturing byproduct.
12. New York State Senate. (n.d.). Environmental Conservation Law § 35-0105: Distribution and sale of household cleansing products.
13. New York State Senate. (n.d.). Environmental Conservation Law § 35-0103: Definitions.
14. New York State Senate. (n.d.). Environmental Conservation Law § 37-0117: Prohibition of cosmetic products and personal care products containing 1,4-dioxane or mercury.
15. New York State Department of Environmental Conservation. (n.d.). 1,4-Dioxane limits for household cleansing, personal care, and cosmetic products.
16. New York State Department of Environmental Conservation. (2024, September 18). DEC finalizes regulations restricting 1,4-dioxane in consumer products.
17. Adamson, D. T., Piña, E. A., Cartwright, A. E., Rauch, S. R., Anderson, R. H., Mohr, T., & Connor, J. A. (2017). 1,4-Dioxane drinking water occurrence data from the third unregulated contaminant monitoring rule. Science of the Total Environment, 596-597, 236-245. https://doi.org/10.1016/j.scitotenv.2017.04.085
Transparency Note
Educational guide under Green Llama's E-E-A-T and Trust Framework. Not medical or legal advice. This page replaces an earlier version whose classification language, New York limit, and product-formula claims were out of date. Scientific review of the update by Matthew Keasey, Ph.D., is pending, and every chemistry and health claim is flagged for it. Agency documents, statutes, and product details were checked against the cited sources on August 14, 2026; classifications and laws change, so verify before acting. Always follow product labels, and store cleaning products away from children and pets.
Non-Toxic Laundry Detergent: The Ingredient-by-Ingredient Guide
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Read the guide →The Laundry Detergent Ingredients Glossary
Decode every name on a detergent label, including where 1,4-dioxane comes from.
Decode your label →What Is Non-Toxic Laundry Detergent?
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Get the definition →Best Non-Toxic Laundry Detergents of 2026
An ingredient-tested comparison that applies these same red-flag checks across brands.
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