Is borax safe to clean with?

Borax (sodium tetraborate decahydrate) is a mild alkali used as a laundry booster and a scrubbing powder, and the honest answer on safety is that the hazard documents disagree. The European Union classifies it in reproductive toxicity Category 1B: "May damage fertility. May damage the unborn child." A 2018 US Safety Data Sheet for 20 Mule Team Borax puts it in the lower Category 2, "suspected of" those effects, plus skin and eye irritation. An EPA-accepted borax label carries the signal word DANGER for eye irritation and harm if swallowed. All of them say to keep it out of eyes, mouths and children's reach. This page sets out what each says, how borax is used, and what to use instead.

What the hazard documents say

The European Chemicals Agency's own extract of the EU harmonised list (CLP Annex VI) confirms the entry for borax itself: index number 005-011-01-1, "disodium tetraborate decahydrate; borax decahydrate," Repr. 1B, H360FD, with a specific concentration limit of "C ≥ 8,5 %" [14]. In the EU, that means a mixture containing 8.5 percent or more borax decahydrate takes the same reproductive toxicity classification. ECHA's risk assessment committee, in a 2014 opinion on a related borate (disodium octaborate), wrote: "As borates are classified in category 1B, the GCL is 0.3% w/w" [5]. That generic concentration limit (GCL) is the fallback where no specific limit is set. Borax has its own limit in the Annex VI entry, so 8.5 percent is the figure that applies to it.

The National Pesticide Information Center's fact sheet on boric acid and the sodium borate salts, borax among them (reviewed December 2013), takes a different angle. It calls boric acid "low in toxicity if eaten or if it contacts skin," says borax "can be corrosive to the eye" and can irritate skin, and reports that EPA "concluded that boric acid is not likely to be carcinogenic to humans" [13]. It does not discuss reproductive effects.

Why the documents disagree

The reproductive findings behind these classifications come from animal studies. ECHA's committee cites a fertility study on disodium tetraborate decahydrate among its evidence for testicular effects [5]. Regulators then decide how much weight those findings carry:

• In the EU the classification is harmonised, so every supplier must print Category 1B.
• The US sheets reach their own conclusions. The 2018 sheet chose Category 2; the 2012 Dial sheet, written before OSHA adopted the GHS classification system, listed no hazard at all.
• The EPA label is a different kind of document: it governs borax sold for pesticide formulation and states the precautions EPA accepted for that product.

Read the most recent SDS for the box you buy. The 2018 US sheet is itself inconsistent in places: it lists four different oral LD50 values for the same substance, from 396 mg/kg to 5,660 mg/kg (rat), without reconciling them [2]. The Dial sheet and the Rio Tinto sheet both give 2,660 mg/kg (rat) [1][3].

What borax is used for

Borax is a mild alkali; a 1 percent solution measures pH 9.2 [1], between baking soda and washing soda. Published uses:

Two notes on those recipes. The toilet methods combine borax with vinegar, an alkali with an acid, which the combinations page explains. And none of these sources claims that borax disinfects; it is used for cleaning and stain removal only.

Borax and children

The maker's own safety page says borax "should not be used undiluted or in contact with the eyes or swallowed," that it is not a personal care product or dietary supplement, and that it belongs "out of reach of children and pets" [9]. If swallowed, the Dial sheet calls for rinsing the mouth, giving water or milk, never giving liquids to an unconscious person, and contacting a physician or poison control center [3].

That last instruction is the one to act on. NPIC adds that infants may be especially sensitive: seizures and deaths have been reported more often in infants with long-term exposure than in adults [13]. If a child eats borax or a borax mix, call Poison Control at 1-800-222-1222 [10]. Household cleaning substances were the leading substance category in poison center exposures among children 5 and under in 2024 [10], and a white powder in an unmarked jar is exactly how those exposures happen. Children and pets get their own page: cleaning around kids and pets.

Borax is also not for slime, bath or skin recipes. Its maker says not to bathe in it or apply it to skin [9].

Dust

The hazard most people overlook is breathing the powder while scooping. The Dial sheet lists the ACGIH exposure limits for inorganic borates at 2 mg/m³ over an 8-hour average and 6 mg/m³ short term [3], and the Rio Tinto sheet gives the same ACGIH figures for the inhalable fraction [1]. Those are workplace limits, but they tell you to pour gently, keep your face away from the box and not shake borax into the air.

What borax must not be mixed with

• Acids (vinegar, citric acid): listed as incompatible on the Dial sheet [3]. At home the result is mostly cancellation rather than danger.
• Strong oxidizers: also listed as incompatible [3]. Chlorine bleach is an oxidizer.
• Bleach or any other cleaner, by CDC's general rule for bleach [11].

If you would rather leave borax out

Every published job above has a borax-free route:

• Laundry: washing soda is the other builder in the UF/IFAS recipes [6], and its own hazard is eye and skin irritation rather than reproductive toxicity [12]. The homemade laundry detergent page covers the recipes; the washing soda page covers its handling.
• Scrubbing: NMSU's powdered cleaner lets you choose baking soda, chalk, pumice, salt or washing soda [7]; baking soda is the lowest-hazard choice of those with a maker's SDS read here.
• Toilets: the toilet bowl page covers published methods and when a registered product is the right call.

Storing borax

Dial's sheet: "Store in original containers in a cool dry area" [3]. Keep it high, closed and labeled, never decanted into a sugar or flour canister, and well apart from bleach. Damp borax cakes, so keep the lid on.

For makers who sell a borax product

A product containing borax raises the hazard-labeling questions in the federal Hazardous Substances Act, which turn on the product's toxicity and irritancy at the strength sold, and buyers in the EU will apply the Category 1B classification. Start with the is it hazardous page before you print a label.

Deciding whether borax belongs in your cupboard

If you have young children, the borax-free routes above remove one more hazardous powder from the house. If you keep it, keep it like any hazardous product: original box, high shelf, gloves for scrubbing and no dust in the air. Either way, the homemade laundry detergent page is the next stop for most borax users.

References

1. Rio Tinto (Borax Europe Limited), Safety Data Sheet: Borax Decahydrate, Refining Grade, version 1.01, November 18, 2022. https://sds.riotinto.com/display/rtm/FileName-509234
2. Educational Innovations, Inc. (text refers to Henkel Corporation), Safety Data Sheet: 20 Mule Team Borax, revision 001.3, April 9, 2018. https://westliberty.edu/health-and-safety/files/2021/03/Borax.pdf
3. The Dial Corporation, Material Safety Data Sheet: Borax (20 Mule Team Borax Natural Laundry Booster), revision 9, March 29, 2012. https://employees.delta.edu/facilities/_safety-data-sheets/borax-dial.pdf
4. U.S. Borax Inc., EPA-accepted label: 20 Mule Team Borax, Manufacturing Grade, EPA Reg. No. 1624-124, 2003. https://www3.epa.gov/pesticides/chem_search/ppls/001624-00124-20030805.pdf
5. European Chemicals Agency, Committee for Risk Assessment, Opinion proposing harmonised classification and labelling at EU level of disodium octaborate anhydrate, adopted March 14, 2014. https://echa.europa.eu/documents/10162/7d740d8c-5cd5-872b-5da2-e549983a9ff9
6. University of Florida IFAS Extension, Griffin and Cantrell, Homemade Household Cleaners (FCS3319), Release Date October 7, 2025. https://ask.ifas.ufl.edu/publication/FY1449
7. New Mexico State University Cooperative Extension, Griffiths and Koukel, Green Alternatives to Toxic Household Products and Hazardous Waste (G-313), revised February 2019. https://pubs.nmsu.edu/_g/G313/index.html
8. University of Georgia Cooperative Extension (Pamela R. Turner and Sharon M. S. Gibson), *Green Cleaning: Recipes for a Healthy Home*, HACE-E-73-1 (Green Clean Booklet), revised October 2018. https://site.extension.uga.edu/greenway/files/2024/09/10.18_Green-Clean-Booklet_update.pdf
9. 20 Mule Team, Safety Information, undated, read October 2026. https://20muleteamlaundry.com/safety-information
10. Poison Control (National Capital Poison Center), Poison Statistics: National Data 2024. https://www.poison.org/poison-statistics
11. Centers for Disease Control and Prevention, Cleaning and Disinfecting with Bleach, last reviewed April 24, 2024. https://www.cdc.gov/hygiene/about/cleaning-and-disinfecting-with-bleach.html
12. Church & Dwight Co., Inc., Safety Data Sheet: Arm & Hammer Super Washing Soda, version 1.0, October 2, 2015. https://uwaterloo.ca/fine-arts/sites/default/files/uploads/documents/arm_and_hammer_washing_soda_10-02-2015.pdf
13. National Pesticide Information Center, Oregon State University, *Boric Acid General Fact Sheet*, reviewed December 2013. https://www.npic.orst.edu/factsheets/boricgen.html
14. European Chemicals Agency, *Annex 5: Extract from Annex VI of CLP of substances where SCL was set by the TC C&L*, undated, read October 2026. https://www.echa.europa.eu/documents/10162/17233/annex_5_tpp_odd_extract_from_annex_vi_of_clp_en.pdf/277bd887-b9e4-4d63-a097-2994b74a8870