How much 1,4-dioxane exposure is too much?
A probable human carcinogen (EPA Group B2, IARC Group 2B) that forms as an invisible byproduct during the manufacturing of common surfactants found in laundry detergents, shampoos, and household cleaners. Because it is a manufacturing contaminant -- not an intentional ingredient -- it never appears on ingredient labels, yet testing has found measurable levels in many conventional detergents. New York State was the first US jurisdiction to set a legal limit of 1 part per million in 2023.
Renee · Founder & Lead Researcher, R3
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1,4-Dioxane is a synthetic organic solvent with the molecular formula C4H8O2 (CAS number 123-91-1). At room temperature it is a colorless liquid with a faint ether-like smell. It does not occur naturally in meaningful quantities. It is produced industrially in two main contexts: as a solvent in chemical manufacturing and, critically, as an unintentional byproduct when certain surfactants are manufactured through a process called ethoxylation.
The ethoxylation problem is the reason this chemical matters for families doing laundry. When manufacturers make surfactants like sodium laureth sulfate (SLES), sodium lauryl ether sulfate (SLES), or polyethylene glycol (PEG) compounds, they react a fatty alcohol or other organic compound with ethylene oxide under pressure. This chemical reaction produces the desired surfactant -- but it also produces 1,4-dioxane as a residual contaminant. The 1,4-dioxane is not intentionally added. It is not listed as an ingredient. And because federal labeling law only requires disclosure of intentional ingredients, it is legally invisible to any parent trying to read a product label.
This is not a trace-level theoretical concern. Studies by the Environmental Working Group, Mamavation, and independent researchers have found 1,4-dioxane at levels ranging from below detection to more than 25 parts per million (ppm) in commercial laundry detergents. A 2021 Mamavation investigation tested 20 laundry products and found 1,4-dioxane in 14 of them -- 70% of those tested -- at concentrations ranging from 0.1 ppm to 25.5 ppm.
Ethoxylation is one of the most common industrial reactions in consumer product chemistry. It converts hydrophobic (water-repelling) ingredients into hydrophilic (water-attracting) molecules, enabling surfactants to simultaneously grab onto grease and rinse away with water. The resulting compounds are central to the cleaning performance of most conventional detergents, shampoos, and body washes.
The signature of ethoxylated ingredients on a label is the suffix "-eth-" or the prefix "PEG-". Examples include:
When ethylene oxide reacts with these precursor compounds, 1,4-dioxane forms in the reaction vessel as a structural byproduct. Most manufacturers purge or vacuum-strip some of the 1,4-dioxane before packaging, but this step is voluntary, unregulated at the federal level, and not universally applied. The degree of removal varies significantly by manufacturer and batch.
Products that avoid ethoxylated surfactants entirely cannot contain 1,4-dioxane through this pathway. This is why the safest detergents -- including Branch Basics Concentrate, Blueland Laundry Detergent Tablet Unscented, and Meliora Unscented Laundry Powder -- are formulated without any ethoxylated ingredients.
1,4-Dioxane is classified as a probable human carcinogen (Group B2) by the US Environmental Protection Agency, based on sufficient evidence of carcinogenicity in animals and limited human data. The International Agency for Research on Cancer (IARC) classifies it as Group 2B -- possibly carcinogenic to humans.
The animal evidence is robust. In National Toxicology Program (NTP) studies, rodents exposed to 1,4-dioxane developed liver tumors, nasal cavity tumors, and peritoneal mesothelioma at multiple dose levels. These effects were observed across species (rats and mice) and by multiple exposure routes (oral and inhalation).
Human epidemiological data is more limited, partly because direct occupational exposures involve confounders and partly because no single consumer product category has historically tracked cumulative 1,4-dioxane exposure with adequate longitudinal follow-up. However, the mechanistic evidence -- that 1,4-dioxane causes oxidative DNA damage and cell proliferation in liver and nasal epithelial tissues -- is considered sufficient by the EPA to justify the probable carcinogen classification without waiting for definitive human cohort data.
Laundry detergent is a meaningful 1,4-dioxane exposure pathway for several reasons:
Dermal contact: Residue from laundry detergent remains on fabric after washing and rinsing, particularly with standard washer cycles. Clothing and bedding worn against skin all day (especially infants in onesies and in their crib sheets) represent continuous low-level dermal contact with any compounds that survive the rinse cycle.
Inhalation: Hot water cycles and dryers aerosolize trace volatile compounds from detergent residue. 1,4-Dioxane is volatile enough (boiling point 101C, vapor pressure 29 mmHg at 20C) that it can off-gas from warm laundry into indoor air.
Infant vulnerability: Infants spend the most time against washed fabric (clothing, swaddles, crib sheets, burp cloths) per unit body weight and have greater skin surface area relative to body mass than adults. Their skin barrier is also more permeable than adult skin in the first several months of life.
Dreft Stage 1 Newborn -- one of the most widely used infant laundry detergents -- was found to contain 1,4-dioxane in independent testing at levels above 1 ppm. This is one of the most important product findings in this space, because the marketing of that product specifically targets the infant laundry category. Dreft Stage 1: Newborn Baby Liquid Laundry Detergent contains ethoxylated surfactants and has tested positive for 1,4-dioxane contamination in third-party lab analysis.
1,4-Dioxane is also a documented groundwater contaminant from industrial spills and waste. The EPA has been developing a maximum contaminant level (MCL) for 1,4-dioxane in drinking water. The current EPA lifetime health advisory is 0.35 micrograms per liter (mcg/L), which represents a theoretical 1 in 100,000 cancer risk over a lifetime of drinking water at that concentration. The EPA's drinking water risk assessment provides independent confirmation of its carcinogenic potency at low concentrations.
New York State enacted the first legally binding consumer product limit for 1,4-dioxane in the United States. Under New York 1,4-dioxane limit (DEC Regulation 6 NYCRR Part 659), effective December 31, 2023 for laundry detergents and other consumer cleaning products:
This is the strictest 1,4-dioxane limit for consumer products in the United States and one of the strictest in the world. Companies selling products in New York State must comply, and because New York is the fourth-largest consumer market in the US, most major manufacturers have chosen to reformulate nationally rather than maintain separate product lines.
The US FDA and EPA have not set a federal maximum limit for 1,4-dioxane in consumer cleaning products or laundry detergents. The FDA has published guidance suggesting manufacturers voluntarily reduce 1,4-dioxane to below 10 ppm in cosmetic products -- but this guidance is not enforceable and does not cover household cleaning products.
This regulatory gap means that in 49 states other than New York, there is no legal requirement for laundry detergents to test for or disclose 1,4-dioxane levels. Consumers cannot rely on federal standards to protect them; product selection becomes the primary control.
The EPA Safer Choice certification program prohibits ingredients that are "reasonably anticipated to be human carcinogens" -- which excludes surfactants with unacceptable 1,4-dioxane contamination levels. However, Safer Choice evaluates ingredient safety rather than finished product testing, and the program does not currently require third-party 1,4-dioxane testing at the finished product level. Products with Safer Choice certification are lower risk but not mathematically guaranteed to be at or below any specific 1,4-dioxane threshold.
California's Toxic-Free Cosmetics Act, effective January 2025, prohibited 24 chemicals in cosmetics sold in California -- but this covers cosmetics, not household cleaning products. Laundry detergent is regulated separately from cosmetics and is not covered by this act.
This is the most frustrating aspect of 1,4-dioxane for anyone trying to protect their family: you cannot read it on any label. Federal law requires disclosure of intentional ingredients, not manufacturing byproducts. 1,4-Dioxane is a contaminant formed during synthesis, not an ingredient added to the formula.
Instead, you identify risk by the *presence of ethoxylated surfactants* in the ingredient list. Any ingredient with these markers is potentially contaminated:
If none of these appear in the ingredient list, the product cannot contain 1,4-dioxane via the ethoxylation pathway.
For confirmed verification, look for: - Third-party 1,4-dioxane testing results published by the manufacturer - Mamavation-tested products listed as below detection limits - 1,4-dioxane-free claim backed by certificates of analysis
Branch Basics Concentrate is formulated without any ethoxylated surfactants. It uses plant-based surfactants (decyl glucoside, lauryl glucoside) that are not produced via ethoxylation and therefore cannot contain 1,4-dioxane from that pathway. Branch Basics publishes full ingredient transparency.
Blueland Laundry Detergent Tablet Unscented is a powder tablet format that uses surfactants derived from coconut and corn without ethoxylation. The zero-plastic packaging is an additional benefit, and Blueland maintains ingredient transparency on its website.
Meliora Unscented Laundry Powder uses washing soda, baking soda, and soap flakes -- none of which are ethoxylated. This is one of the most minimal-ingredient laundry products on the market.
Molly's Suds Liquid Laundry Detergent 2x Concentrated Unscented is formulated without ethoxylated surfactants and without synthetic fragrance.
ECOS Plant-Powered Laundry Detergent Free & Clear has been tested by third parties and found to be at or near detection limits for 1,4-dioxane. ECOS uses Earth Friendly Products' own 1,4-dioxane reduction process and publishes test results. While their formula does contain some ethoxylated compounds, the manufacturer actively tests and controls for 1,4-dioxane levels.
Puracy Natural Laundry Detergent Free & Clear uses glucoside-based surfactants and publishes its ingredient list with safety data. Puracy has stated publicly that it tests for 1,4-dioxane and maintains levels below 1 ppm.
Tide Original Scent Liquid Laundry Detergent uses sodium laureth sulfate and other ethoxylated surfactants as primary cleaning agents. Third-party testing has found 1,4-dioxane in Tide products at levels significantly above 1 ppm in some test batches, though levels can vary by formulation year and testing methodology.
Dreft Stage 1: Newborn Baby Liquid Laundry Detergent is particularly concerning given its target market. Despite being marketed for newborns as "gentle," Dreft contains sodium laureth sulfate and has tested positive for 1,4-dioxane above 1 ppm. The NY State 1 ppm limit specifically targeted this category of baby laundry products.
The actionable steps are straightforward, especially for families with infants or young children who are in the highest-exposure category:
Switch to an ethoxylation-free detergent. This is the single most reliable intervention. Products formulated without -eth- surfactants or PEG compounds cannot contain 1,4-dioxane from manufacturing. Branch Basics, Blueland, and Meliora all qualify and perform well in cleaning tests.
For infants specifically, prioritize the swap immediately. Crib sheets, onesies, sleep sacks, and swaddles are in continuous contact with your baby's skin. If you are currently using Dreft, Tide, or another conventional detergent with ethoxylated surfactants, this is a high-leverage swap.
Extra rinse cycle when using conventional detergents. An additional rinse cycle reduces the amount of detergent residue remaining on fabric, lowering the dermal contact dose. This is a harm-reduction measure while transitioning products, not a solution.
Check Mamavation's tested product list. Mamavation has published 1,4-dioxane testing results for dozens of laundry products and updates the list as new tests are completed. This is the most current database of actual measured levels in consumer products.
The most commonly recommended baby laundry detergent in the US contains sodium laureth sulfate and has tested positive for 1,4-dioxane above the NY State 1 ppm limit. For newborns and infants, whose skin barrier is more permeable and who are in contact with washed fabric all day and night, switching to an ethoxylation-free detergent is one of the highest-leverage safety swaps in the whole nursery. Branch Basics Concentrate, Blueland Tablets, and Meliora Powder are all formulated without any -eth- or PEG- surfactants -- meaning they cannot contain 1,4-dioxane from manufacturing.
Probable human carcinogen: The EPA classifies 1,4-dioxane as Group B2 (probable human carcinogen) based on robust animal evidence. Rodent studies by the National Toxicology Program documented liver tumors, nasal cavity tumors, and peritoneal mesothelioma at multiple dose levels across species. IARC classifies it as Group 2B (possibly carcinogenic to humans).
Carcinogenic mechanism: 1,4-Dioxane causes oxidative DNA damage and induces cell proliferation in liver and nasal epithelial tissues -- the same tissues where tumors were observed in animal studies. Unlike some carcinogens that act at specific receptor sites, 1,4-dioxane works through broad genotoxic mechanisms.
EPA drinking water risk: The EPA lifetime health advisory of 0.35 mcg/L (ppb) in drinking water represents a 1-in-100,000 theoretical cancer risk over a lifetime of continuous exposure -- establishing that even very low concentrations are considered meaningful from a risk standpoint.
Skin absorption and inhalation: 1,4-Dioxane is absorbed through skin and inhaled as a vapor. Laundry detergent residue on fabric creates ongoing low-level dermal contact, especially for infants and young children whose skin barrier is more permeable than adults and who have greater surface-area-to-body-mass ratios.
Lacks natural breakdown signals: 1,4-Dioxane is resistant to conventional water treatment processes, which is why it is a persistent groundwater contaminant once released. This persistence also means it is not rapidly metabolized and can accumulate with repeated exposure.
New York State (2023 -- first US limit): DEC Regulation 6 NYCRR Part 659 sets a 1 ppm maximum for 1,4-dioxane in laundry detergents and household cleaning products sold in NY, effective December 31, 2023. This is the strictest state-level consumer product limit in the United States.
US EPA (drinking water): Lifetime health advisory of 0.35 mcg/L. An EPA maximum contaminant level (MCL) rulemaking has been under development; 1,4-dioxane was included in the Contaminant Candidate List (CCL 4 and CCL 5), signaling active federal consideration.
US FDA (cosmetics): Non-binding guidance recommending manufacturers reduce 1,4-dioxane in cosmetic products to below 10 ppm. Not enforceable; does not cover household cleaning products or laundry detergents.
Federal consumer products: No current federal maximum limit for 1,4-dioxane in laundry detergent, dish soap, or other household cleaning products. Manufacturers are not required to test for or disclose 1,4-dioxane content.
EPA Safer Choice: Prohibits ingredients classified as probable carcinogens, which provides indirect protection -- but does not require finished-product 1,4-dioxane testing at a specific ppm threshold.
California: The Toxic-Free Cosmetics Act (effective January 2025) does not cover laundry detergents. California's Cleaning Product Right to Know Act requires disclosure of intentional ingredients only -- manufacturing byproducts like 1,4-dioxane are still exempt.
How to reduce exposure
Switching to an ethoxylation-free laundry detergent is the most reliable intervention -- products formulated without any -eth- surfactants or PEG compounds cannot contain 1,4-dioxane from manufacturing contamination. For families not yet ready to switch, an extra rinse cycle reduces detergent residue on fabric and lowers dermal exposure. Checking Mamavation's published third-party test results provides the most current data on actual 1,4-dioxane levels in specific products. For infant laundry specifically, the swap to an ethoxylation-free detergent is the highest-leverage single change given continuous fabric-to-skin contact.
Who is most at risk
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Timeline
2007
FDA Guidance Published
FDA published guidance recommending manufacturers reduce 1,4-dioxane in cosmetic products to below 10 ppm -- the first federal agency acknowledgment of consumer product contamination. Guidance was non-binding and limited to cosmetics, not cleaning products.
2008
EWG Testing Report
Environmental Working Group published testing data showing 1,4-dioxane in dozens of baby bath products and shampoos, raising public awareness of the labeling transparency gap for manufacturing byproducts.
2019
EPA Contaminant Candidate List 4
EPA included 1,4-dioxane on Contaminant Candidate List 4 (CCL 4), the agency's priority list for potential drinking water regulation. This signaled escalating federal concern about the compound's carcinogenic risk.
2021
Mamavation Laundry Testing
Mamavation published third-party lab results for 20 laundry detergents, finding 1,4-dioxane in 14 (70%). Levels ranged from below detection to 25.5 ppm. Results highlighted the gap between baby-marketed products and actual safety performance.
2022
New York Law Enacted
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Federal labeling law only requires disclosure of intentional ingredients. 1,4-Dioxane is a manufacturing contaminant -- it forms as a byproduct when surfactants like sodium laureth sulfate are produced via ethoxylation, but it is never deliberately added to the formula. Because it is not an ingredient, manufacturers have no legal obligation to list it. The only way to know if a product contains it is through third-party testing or by checking whether the formula contains ethoxylated surfactants (any ingredient with -eth- or PEG-).
The EPA classifies 1,4-dioxane as a Group B2 probable human carcinogen based on robust animal data from National Toxicology Program studies showing tumors at multiple sites. The concern is real and backed by toxicological evidence, not speculation. That said, the risk is proportional to cumulative exposure over time -- a single wash is not acutely dangerous. The concern is the low-level daily exposure from clothing and bedding fabric residue, especially for infants whose skin is more permeable and who have greater surface-area-to-body-weight ratios. Given that safer alternatives are readily available and similarly priced, switching is a straightforward risk reduction.
Yes. Dreft Stage 1: Newborn contains sodium laureth sulfate as a primary surfactant, which is produced via ethoxylation. Independent third-party testing by Mamavation and others has found 1,4-dioxane in Dreft formulations above the 1 ppm NY State limit. The "gentle" and "baby" marketing language refers to the fragrance and dye formulation, not to the absence of manufacturing contaminants. This is one of the most important findings in this space precisely because the product is specifically positioned for the most vulnerable age group.
Products formulated without any ethoxylated surfactants cannot contain 1,4-dioxane from manufacturing. The clearest examples are Branch Basics Concentrate (uses decyl and lauryl glucoside), Blueland Laundry Tablets (coconut and corn-derived surfactants, no ethoxylation), and Meliora Unscented Laundry Powder (washing soda, baking soda, soap flakes). Molly's Suds is also formulated without ethoxylated surfactants. For products that use some ethoxylated ingredients but test clean, ECOS and Puracy both publish third-party testing results showing levels at or near detection limits.
An extra rinse cycle reduces the total amount of detergent residue remaining on fabric, which in turn lowers the amount of any contaminant -- including 1,4-dioxane -- in contact with skin. It is a harm-reduction step, not a solution. 1,4-Dioxane is water-soluble, so additional rinsing does remove some residue. But the most reliable approach is switching to a detergent formulated without ethoxylated surfactants so the contaminant isn't present to begin with.
New York State's 1 ppm maximum for 1,4-dioxane in laundry detergents (effective December 31, 2023) is the first US legal limit and one of the strictest in the world. Because New York is a major market, most large manufacturers reformulated nationally to comply rather than maintain separate product lines. So the NY law has had a practical effect beyond New York's borders. However, 1 ppm is a regulatory threshold set based on analytical feasibility and industry capability -- it is not a threshold below which there is zero cancer risk. Products at 1 ppm still contain 1,4-dioxane. Products formulated without ethoxylated surfactants contain none.
Not with certainty. EPA Safer Choice evaluates ingredient safety and prohibits ingredients classified as probable carcinogens -- so surfactants with known 1,4-dioxane contamination issues face scrutiny during certification. However, Safer Choice does not require independent finished-product testing for 1,4-dioxane at a specific ppm threshold. A Safer Choice product has lower inherent risk, but for confirmed 1,4-dioxane-free status, look for products that either use no ethoxylated surfactants or publish third-party certificates of analysis showing tested levels.
Look for the [EPA Safer Choice](/learn/certifications/epa-safer-choice) label. While not a guarantee of sub-1 ppm levels, Safer Choice products have lower inherent risk because the program screens ingredient chemistry. It is a meaningful secondary filter, not a primary safety guarantee.
The New York 1,4-dioxane limit is a regulatory signal that federal action will likely follow, as it did with BPA restrictions that started at the state level. In the meantime, product selection is the primary control families have.
New York Governor signed the 1,4-dioxane consumer product legislation into law, establishing the first US statutory limit of 1 ppm in laundry detergents, dish soaps, and household cleaning products. Implementation deadline set for December 31, 2023.
2023
NY 1 ppm Limit Takes Effect
DEC Regulation 6 NYCRR Part 659 became enforceable. Laundry detergents sold in New York State must contain no more than 1 ppm 1,4-dioxane. Most major manufacturers reformulated nationally to comply, effectively improving product safety across the US market.
2025
EPA CCL 5 Inclusion
EPA included 1,4-dioxane on Contaminant Candidate List 5, maintaining its status as a priority drinking water regulatory candidate. Federal consumer product regulation remains pending.
A label claim appearing on laundry detergent and personal care products asserting the absence of 1,4-dioxane, a probable human carcinogen that forms as a manufacturing byproduct during ethoxylation. There is no federal definition for this claim, no required testing, and no government body that verifies it before a brand prints it on a bottle. The most honest version of this label points toward a genuinely cleaner product -- but without third-party testing or a recognized certification, parents cannot tell the two apart from the packaging alone.