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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 cleanser117 products
facial moisturizer/treatment84 products
moisturizer66 products
body wash/cleanser65 products
mask58 products
serums & essences43 products
antiperspirant/deodorant40 products
liquid hand soap30 products
conditioner29 products
recreational sunscreen29 products
shampoo25 products
toners/astringents24 products
exfoliant/scrub24 products
shaving cream23 products
foundation20 products
hair spray19 products
shaving cream (men's)13 products
daily use with SPF12 products
around-eye cream12 products
hand cream11 products
toothpaste10 products
foot moisturizer9 products
mascara9 products
makeup remover8 products
diaper cream8 products
baby soap8 products
hair styling aide6 products
styling gel/lotion6 products
cuticle treatment6 products
hair treatment/serum6 products
brow liner5 products
baby shampoo5 products
hair color and bleaching5 products
nail treatment5 products
eye liner4 products
anti-aging4 products
after shave4 products
concealer3 products
baby sunscreen3 products
foot odor control3 products
2 products
detangler2 products
bath oil/salts/soak2 products
sunless tanning2 products
body spray2 products
depilatory2 products
nail polish2 products
baby lotion2 products
bronzer/highlighter2 products
foot cleansing2 products
blush2 products
tooth whitening2 products
body firming lotion2 products
bubble bath1 products
setting powder/spray1 products
other men's products1 products
baby toothpaste1 products
damaged skin treatment1 products
bar soap1 products
muscle/joint soreness1 products
lip balm1 products
after sun product1 products
makeup primer1 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 expected to be toxic or harmfulEnvironment Canada Domestic Substance List
Classified as medium human health priorityEnvironment 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

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

Miscellaneous

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

Persistence and bioaccumulation

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CONCERN REFERENCE
Not suspected to be bioaccumulativeEnvironment Canada Domestic Substance List

Informational

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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

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

Data gaps

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CONCERN REFERENCE
2405 studies in PubMed science library may include information on the toxicity of this chemicalNLM PubMed
  • 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.
  • 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.
  • NLM (National Library of Medicine). 2012. PubMed online scientific bibliography data. http://www.pubmed.gov.

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

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

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