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HOW WE DETERMINE SCORES Learn more About EWG VERIFIED®

Data: Fair

Potassium Hydroxide

  • This ingredient’s score is higher if used in products that are inhalable (e.g., sprays, powders) because of respiratory concerns.
  • Products with this ingredient are allowed for use in EWG VERIFIED but must meet use restrictions and warnings based on EWG review of company data.
  • Products with the EWG VERIFIED mark have met use restrictions and warnings based on EWG review of company data.
  • This ingredient’s score is lower when used as a saponification agent (e.g., soaps and cleansers)

IMAGE SOURCE: PubChem

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Other Concerns

Use restrictions (high), Non-reproductive organ system toxicity (moderate), Irritation (skin, eyes, or lungs) (low), and Occupational hazards (high)

SYNONYMS

● CAUSTIC POTASH
● CAUSTIC POTASH; POTASSIUM HYDROXIDE; POTASSIUM HYDROXIDE
● POTASSIUM HYDROXIDE
● POTASSIUM HYDROXIDE (K(OH))

Restricted

Restricted: EWG VERIFIED products cannot contain this ingredient without adequate substantiation

Potassium Hydroxide is a caustic inorganic base.

Common concerns

See how this product scores for common concerns.

  • LOW
    Cancer
  • LOW
    Allergies & Immunotoxicity
  • LOW
    Developmental and Reproductive Toxicity
  • HIGH
    Use Restrictions

Ingredient concerns

  • CONCERNS
  • DATA SOURCES

Products with this Ingredient

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facial cleanser115 products
facial moisturizer/treatment92 products
moisturizer71 products
mask66 products
body wash/cleanser49 products
serums & essences47 products
antiperspirant/deodorant39 products
exfoliant/scrub31 products
recreational sunscreen31 products
conditioner26 products
toners/astringents24 products
liquid hand soap24 products
shaving cream (men's)24 products
shaving cream22 products
mascara18 products
hair spray18 products
shampoo17 products
foundation15 products
around-eye cream15 products
hand cream14 products
makeup remover11 products
daily use with SPF11 products
styling gel/lotion9 products
hair styling aide9 products
foot moisturizer9 products
diaper cream8 products
toothpaste8 products
hair treatment/serum6 products
baby soap6 products
brow liner6 products
cuticle treatment5 products
hair color and bleaching5 products
nail treatment5 products
concealer4 products
anti-aging4 products
baby sunscreen3 products
baby shampoo3 products
body firming lotion3 products
sunless tanning3 products
after shave3 products
body oil2 products
baby lotion2 products
lip balm2 products
2 products
eye liner2 products
makeup primer2 products
bronzer/highlighter2 products
foot cleansing2 products
bath oil/salts/soak2 products
detangler2 products
muscle/joint soreness2 products
nail polish2 products
foot odor control1 products
body spray1 products
lipstick1 products
lip gloss1 products
damaged skin treatment1 products
baby toothpaste1 products
other men's products1 products
setting powder/spray1 products
after sun product1 products
bubble bath1 products
tooth whitening1 products
bar soap1 products

Use restrictions

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CONCERN REFERENCE
Violation of government restrictions - Restricted in cosmetics; use, concentration, or manufacturing restrictions - anyOpen scientific literature
Violation of industry recommendations - Restricted in cosmetics; use, concentration, or manufacturing restrictions - Avoid or minimize skin exposure: recommendation from industry safety panel (Cosmetic Ingredient Review, CIR)Cosmetic Ingredient Review Assessments
Restricted in cosmetics (recommendations or requirements) - use, concentration, or manufacturing restrictions - anyCosIng
Determined safe for use in cosmetics, subject to concentration or use limitations - Safe for use in cosmetics with some qualificationsCosmetic Ingredient Review Assessments

Occupational hazards

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CONCERN REFERENCE
Allowed workplace exposures restricted to low dosesCPS&Q - Classification & Labelling
Single case study detailing occupational hazardsNational Library of Medicine HazMap

Organ system toxicity (non-reproductive)

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CONCERN REFERENCE
Classified as medium human health priorityEnvironment Canada Domestic Substance List
Classified as expected to be toxic or harmfulEnvironment Canada Domestic Substance List
Classified as toxic or harmfulOpen scientific literature

Irritation (skin, eyes, or lungs)

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CONCERN REFERENCE
Limited evidence of any irritationOpen scientific literature
any irritation - weight of evidence unknown/unassessedOpen scientific literature

Ecotoxicology

Expand content Collapse content
CONCERN REFERENCE
Wildlife and environmental toxicityOpen scientific literature
Not suspected to be an environmental toxinEnvironment Canada Domestic Substance List

Miscellaneous

Expand content Collapse content
CONCERN REFERENCE
Occupational hazards related to handlingCPS&Q - Classification & Labelling

Persistence and bioaccumulation

Expand content Collapse content
CONCERN REFERENCE
Not suspected to be bioaccumulativeEnvironment Canada Domestic Substance List

Informational

Expand content Collapse content
CONCERN REFERENCE
Industry or government recommendations for safe use: restrictions on concentration, impurities, product types, or manufacturing methods - Avoid or minimize skin exposure: recommendation from industry safety panel (Cosmetic Ingredient Review, CIR)Cosmetic Ingredient Review Assessments

Data gaps

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CONCERN REFERENCE
2405 studies in PubMed science library may include information on the toxicity of this chemicalNLM PubMed

Multiple, additive exposure sources

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CONCERN REFERENCE
Designated as safe for general or specific, limited use in foodFDA Everything Added to Food
Designated as safe for general or specific, limited use in foodFDA Food Additive Status
  • Open scientific/peer reviewed literature
  • CIR (Cosmetic Ingredient Review). 2006. CIR Compendium, containing abstracts, discussions, and conclusions of CIR cosmetic ingredient safety assessments. Washington DC.
  • European Commission. 2013. Cosing, the European Commission database with information on cosmetic substances and ingredients. Accessed on March 1, 2013 at http://ec.europa.eu/consumers/cosmetics/cosing/ .
  • CPS&Q (Consumer Products Safety & Quality) formely known as ECB (European Chemicals Bureau). 2008. Classification and Labelling: Chemicals: Annex VI of Directive 67/548/EEC through the 31st ATP.
  • NLM (National Library of Medicine). 2006. HazMap — Occupational Exposure to Hazardous Agents.
  • EC (Environment Canada). 2008. Domestic Substances List Categorization. Canadian Environmental Protection Act (CEPA) Environmental Registry.
  • NLM (National Library of Medicine). 2012. PubMed online scientific bibliography data. http://www.pubmed.gov.
  • FDA (U.S. Food and Drug Administration). 2008. EAFUS [Everything Added to Food]: A Food Additive Database. FDA Office of Food Safety and Applied Nutrition.
  • FDA (U.S. Food and Drug Administration) 2006. Food Additive Status List. Downloaded from http://www.cfsan.fda.gov/%7Edms/opa-appa.html, Oct 16, 2006.

Understanding scores

Cosmetics and personal care products are not required to be tested for safety before being allowed on the market. The Skin Deep® scoring system was designed to help the public understand whether a product is safe to use or whether it contains ingredients of concern.

Every product and ingredient in Skin Deep gets a two-part score – one for hazard and one for data availability. The safest products score well by both measures, with a low hazard rating and a fair or better data availability rating.

HOW WE DETERMINE SCORES

Hazard score

The Skin Deep ingredient hazard score, from 1 to 10, reflects known and suspected hazards linked to the ingredients. The EWG VERIFIED® mark means a product meets EWG’s strictest criteria for transparency and health.

Score legend
WEIGHT-OF-EVIDENCE APPROACH

A product’s hazard score is not an average of the ingredients’ hazard scores. It is calculated using a weight-of-evidence approach that factors in all of the hazards or health impacts associated with the ingredients.

Data availability

The Skin Deep data availability rating reflects the number of scientific studies about the product or ingredient in the published scientific literature.

NONE LIMITED FAIR GOOD ROBUST
Low Availability
Moderate Availability
High Availability
NONE

Ingredients have not been assessed.

LIMITED-FAIR

There is only a modest volume of research.

GOOD-ROBUST

Ingredients have been studied extensively.

Can’t find your product?

Enter the ingredients in EWG’s Build Your Own Report tool to get an approximate score for that product.

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September 23, 2023 | Los Angeles, CA

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