EWG Skin Deep® | What is METHYLISOTHIAZOLINONE

HOW WE DETERMINE SCORES Learn more About EWG VERIFIED™

Data: Fair

Methylisothiazolinone

IMAGE SOURCE: PubChem

SEARCH PRODUCTS

FIND PRODUCTS WITH THIS INGREDIENT

Other Concerns

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

SYNONYMS

● 2-METHYL- 3(2H)-ISOTHIAZOLONE

● 2-METHYL-2H-ISOTHIAZOL-3-ONE

● 2-METHYL-3(2H)-ISOTHIAZOLONE

● 2-METHYL-4-ISOTHIAZOLIN-3-ONE

● 3(2H)-ISOTHIAZOLONE, 2-METHYL-

● 3(2H)ISOTHIAZOLONE, 2METHYL

● METHYLCHLOROISOTHIAZOLINONE225METHYLISOTHIAZOLINONE SOLUTION

● METHYLISOTHIAZOLINONE

Unacceptable

Unacceptable: EWG VERIFIED products cannot contain this ingredient

Methylisothiazolinone is a widely-used preservative; has been associated with allergic reactions. Lab studies on the brain cells of mammals also suggest that methylisothiazolinone may be neurotoxic.

Common concerns

See how this product scores for common concerns.

LOW

Cancer
HIGH

Allergies & Immunotoxicity
LOW

Developmental and Reproductive Toxicity
HIGH

Use Restrictions

Ingredient concerns

CONCERNS
DATA SOURCES

Products with this Ingredient

shampoo	463 products
conditioner	402 products
liquid hand soap	391 products
body wash/cleanser	384 products
hair color and bleaching	61 products
hair treatment/serum	56 products
bubble bath	51 products
facial cleanser	42 products
moisturizer	39 products
hair styling aide	21 products
bath oil/salts/soak	20 products
styling gel/lotion	17 products
recreational sunscreen	17 products
exfoliant/scrub	16 products
facial moisturizer/treatment	14 products
baby shampoo	14 products
mask	13 products
baby wipes	11 products
baby bubble bath	8 products
beard cleanser	8 products
daily use with SPF	7 products
baby soap	6 products
serums & essences	5 products
hand sanitizer	5 products
body cleansing wipes	5 products
body firming lotion	4 products
hair spray	3 products
toners/astringents	3 products
anti-aging	2 products
styling mousse/foam	2 products
after sun product	2 products
eye liner	2 products
foundation	2 products
shaving cream	2 products
bar soap	2 products
	2 products
baby oil	2 products
baby lotion	2 products
muscle/joint soreness	2 products
foot moisturizer	1 products
hand cream	1 products
concealer	1 products
detangler	1 products
around-eye cream	1 products
hair relaxer	1 products
bronzer/highlighter	1 products
blush	1 products
sunless tanning	1 products
nail polish	1 products
body spray	1 products
baby sunscreen	1 products
after shave	1 products
eyelash glue	1 products
damaged skin treatment	1 products
beard care	1 products

Use restrictions

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

Allergies/immunotoxicity

CONCERN	REFERENCE
Known human immune toxicant or allergen	Open scientific literature
Human sensitizer toxicant or allergen - strong evidence	Open scientific literature
Human skin toxicant or allergen - strong evidence	Cosmetic Ingredient Review Assessments
Human any toxicant or allergen - moderate evidence	Open scientific literature
One or more human case studies show significant skin or allergenic effects	Open scientific literature
Limited evidence of immune system toxicity or allergies	National Library of Medicine HazMap

Irritation (skin, eyes, or lungs)

CONCERN	REFERENCE
Possible human skin sensitizer irritant	Open scientific literature

Neurotoxicity

CONCERN	REFERENCE
One or more in vitro tests on mammalian cells demonstrate neurotoxicity	Open scientific literature

Ecotoxicology

CONCERN	REFERENCE
Wildlife and environmental toxicity	Open scientific literature
Not suspected to be an environmental toxin	Environment Canada Domestic Substance List

Data gaps

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 product	Cosmetic Ingredient Review Assessments
331 studies in PubMed science library may include information on the toxicity of this chemical	NLM PubMed

Persistence and bioaccumulation

CONCERN	REFERENCE
Not suspected to be bioaccumulative	Environment Canada Domestic Substance List
Not suspected to be persistent	Environment Canada Domestic Substance List

Organ system toxicity (non-reproductive)

CONCERN	REFERENCE
Classified as not expected to be potentially toxic or harmful	Environment Canada Domestic Substance List

Open scientific/peer reviewed literature
Health Canada. 2007. List of Prohibited and Restricted Cosmetic Ingredients. Canada's Cosmetic Ingredient Hotlist. March 2007.
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.
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.

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.

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