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HOW WE DETERMINE SCORES Learn more About EWG VERIFIED®

Data: Fair

Methylchloroisothiazolinone

IMAGE SOURCE: PubChem

SEARCH PRODUCTS

Other Concerns

Use restrictions (high), Persistence and bioaccumulation (moderate), Ecotoxicology (low), and Irritation (skin, eyes, or lungs) (moderate)

SYNONYMS

● 3(2H)ISOTHIAZOLONE, 5CHLORO2METHYL
● 4-ISOTHIAZOLIN-3-ONE, 5-CHLORO-2-METHYL-
● 5-CHLORO-2-METHYL- 4-ISOTHIAZOLIN-3-ONE
● 5-CHLORO-2-METHYL-2H-ISOTHIAZOL-3-ONE
● 5-CHLORO-2-METHYL-4-ISOTHIAZOLIN-3-ONE
● METHYLCHLOROISOTHIAZOLINONE
● METHYLCHLOROTHIAZOLINONE

Unacceptable

Unacceptable: EWG VERIFIED products cannot contain this ingredient

Methylchloroisothiazolinone is a widely-used preservative; has been associated with allergic reactions.

Common concerns

See how this product scores for common concerns.

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

Ingredient concerns

  • CONCERNS
  • DATA SOURCES

Products with this Ingredient

Expand content Collapse content
shampoo500 products
conditioner424 products
liquid hand soap389 products
body wash/cleanser359 products
hair color and bleaching61 products
bubble bath47 products
hair treatment/serum46 products
facial cleanser36 products
moisturizer35 products
bath oil/salts/soak21 products
styling gel/lotion14 products
exfoliant/scrub12 products
beard cleanser10 products
baby shampoo10 products
mask10 products
hair styling aide9 products
baby bubble bath8 products
baby wipes8 products
body cleansing wipes5 products
4 products
hand sanitizer4 products
baby soap4 products
toners/astringents3 products
hand cream2 products
facial moisturizer/treatment2 products
bar soap2 products
muscle/joint soreness2 products
shaving cream2 products
eyelash glue2 products
hair spray2 products
baby lotion1 products
body spray1 products
styling mousse/foam1 products
beard care1 products
eye liner1 products
baby oil1 products
after sun product1 products
antiperspirant/deodorant1 products
hair relaxer1 products
damaged skin treatment1 products
sunless tanning1 products
lipstick1 products

Use restrictions

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CONCERN REFERENCE
Violation of government restrictions - Banned or found unsafe for use in cosmeticsCanada - Prohibited and Restricted Cosmetics Ingredients
Violation of government restrictions - Restricted in cosmetics; use, concentration, or manufacturing restrictions - anyOpen scientific literature
Restricted in cosmetics (recommendations or requirements) - use, concentration, or manufacturing restrictions - Use is restricted in Canadian cosmeticsCanada - Prohibited and Restricted Cosmetics Ingredients
Restricted in cosmetics (recommendations or requirements) - use, concentration, or manufacturing restrictions - Japan - prohibited for use in some types of cosmetics when combined with certain other ingredientsJapan's Standards for Cosmetics
Determined safe for use in cosmetics, subject to concentration or use limitations - Safe for use in cosmetics with some qualificationsCosmetic Ingredient Review Assessments

Persistence and bioaccumulation

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CONCERN REFERENCE
Persistent or bioaccumulative and moderate to high toxicity concern in humansOpen scientific literature
Not suspected to be persistentEnvironment Canada Domestic Substance List
Not suspected to be bioaccumulativeEnvironment Canada Domestic Substance List

Irritation (skin, eyes, or lungs)

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CONCERN REFERENCE
Possible human skin irritantOpen scientific literature

Allergies/immunotoxicity

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CONCERN REFERENCE
Human skin toxicant or allergen - strong evidenceCosmetic Ingredient Review Assessments
Human skin toxicant or allergen - moderate evidenceOpen scientific literature
One or more human case studies show significant skin or allergenic effectsOpen scientific literature
Limited evidence of immune system toxicity or allergiesScorecard.org Toxicity Information
Limited evidence of immune system toxicity or allergiesNational Library of Medicine HazMap

Cancer

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CONCERN REFERENCE
Mutagen - limited evidenceOpen 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

Data gaps

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CONCERN REFERENCE
Risk assessment method deficiencies and data gaps - Maximum reported "as used" concentration is basis of safety assessment by industry safety panel (Cosmetic Ingredient Review, CIR) - implicit safe concentration limit in productCosmetic Ingredient Review Assessments
232 studies in PubMed science library may include information on the toxicity of this chemicalNLM PubMed

Organ system toxicity (non-reproductive)

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CONCERN REFERENCE
Classified as not expected to be potentially toxic or harmfulEnvironment Canada Domestic Substance List
  • Health Canada. 2007. List of Prohibited and Restricted Cosmetic Ingredients. Canada's Cosmetic Ingredient Hotlist. March 2007.
  • Open scientific/peer reviewed literature
  • Japan Ministry of Health, Labour and Welfare. 2006. Standards for Cosmetics. Evaluation and Licensing Division. Pharmaceutical and Food Safety Bureau.
  • CIR (Cosmetic Ingredient Review). 2006. CIR Compendium, containing abstracts, discussions, and conclusions of CIR cosmetic ingredient safety assessments. Washington DC.
  • EC (Environment Canada). 2008. Domestic Substances List Categorization. Canadian Environmental Protection Act (CEPA) Environmental Registry.
  • ED (Environmental Defense). 2006. Scorecard _ The Pollution Information Site. http://www.scorecard.org.
  • NLM (National Library of Medicine). 2006. HazMap — Occupational Exposure to Hazardous Agents.
  • 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
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?

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September 23, 2023 | Los Angeles, CA

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