Moderate Cosmetic Ingredient NOAEL Data GHS Classified

MEK (Methyl Ethyl Ketone / 2-Butanone)

INCI: MEK (ALSO KNOWN AS 2-BUTANONE / METHYL ETHYL KETONE)

CAS Number
78-93-3
Function
Solvent, denaturant
Safety Rating
MODERATE

Regulatory Status

🇪🇺 EU Status prohibited
🇺🇸 US Status permitted
US Notes Allowed - not specifically prohibited under 21 CFR 700; EPA has classified it as having low acute and low chronic toxicity. OSHA PEL is 200 ppm (590 mg/m³) for occupational exposure.

For full compliance data across 55 jurisdictions, use the Substance Compliance tool.

Safety Data

Margin of Safety (MoS)
not established
Dermal Absorption
low
Sensitization
low

Calculate MoS for your specific formulation with the MoS Calculator.

Toxicological Studies

5 study endpoints found for MEK (Methyl Ethyl Ketone / 2-Butanone). NOAEL (No Observed Adverse Effect Level) values are used to calculate the Margin of Safety per SCCS methodology.

Endpoint Value Route Species Study Type Source
NOAEL 490 mg/kg bw/day oral rat Short Term Toxicity COSMOS_DB
NOAEL 981 mg/kg bw/day oral rat Short Term Toxicity COSMOS_DB
dose_tested 490 mg/kg bw/day oral rat Short Term Toxicity COSMOS_DB
dose_tested 981 mg/kg bw/day oral rat Short Term Toxicity COSMOS_DB
NOEL 500 ppm 1995 rat inhalation REACH

GHS Hazard Classification

Globally Harmonized System classification per ECHA C&L inventory and ILO/WHO International Chemical Safety Cards.

Signal Word
DANGER
Pictograms
flam;flame; excl mark;warn; cancer;health haz
Hazard Statements
Highly flammable liquid and vapour Causes serious eye irritation May cause respiratory irritation May cause drowsiness or dizziness Suspected of damaging fertility or the unborn child May be harmful if swallowed and enters airways
Short-term Exposure Effects
The substance is irritating to the eyes and respiratory tract. The substance may cause effects on the central nervous system. Exposure could cause unconsciousness. If swallowed the substance easily enters the airways and could result in aspiration pneumonitis.
Long-term Exposure Effects
The substance defats the skin, which may cause dryness or cracking. Animal tests show that this substance possibly causes toxicity to human reproduction or development.
Routes of Exposure
The substance can be absorbed into the body by inhalation, by ingestion and through the skin.

Expert Verdict

Strong solvent that can cause skin defatting and irritation on prolonged contact; eye and mucous membrane irritant; CNS depressant at high inhalation concentrations. Flammable (flash point ~−9°C) - significant GMP/safety consideration. Low developmental toxicity concern per EPA assessment.. Rapid evaporation rate; miscible with most organic solvents; DOT classification as flammable liquid (UN 1193). Largely replaced by ethyl acetate and acetone in modern cosmetic formulations due to better sa...

⚠️
Concern Level: High

Regulatory Flags

ifra_fragrance fda_food_additive

Frequently Asked Questions

Is MEK (Methyl Ethyl Ketone / 2-Butanone) safe in cosmetics?

Strong solvent that can cause skin defatting and irritation on prolonged contact; eye and mucous membrane irritant; CNS depressant at high inhalation concentrations. Flammable (flash point ~−9°C) - significant GMP/safety consideration. Low developmental toxicity concern per EPA assessment.. Rapid evaporation rate; miscible with most organic solvents; DOT classification as flammable liquid (UN 1193). Largely replaced by ethyl acetate and acetone in modern cosmetic formulations due to better sa... The EU classifies MEK (Methyl Ethyl Ketone / 2-Butanone) as "prohibited". Safety rating: MODERATE. 5 toxicological study endpoint(s) are available in our database.

Is MEK (Methyl Ethyl Ketone / 2-Butanone) allowed in the EU?

MEK (Methyl Ethyl Ketone / 2-Butanone) EU regulatory status: prohibited. This is based on EU Regulation 1223/2009 and its amendments.

What does MEK (Methyl Ethyl Ketone / 2-Butanone) do in cosmetics?

MEK (Methyl Ethyl Ketone / 2-Butanone) functions as: Solvent, denaturant. It is classified as a cosmetic ingredient in our database. CAS number: 78-93-3.

What is the Margin of Safety for MEK (Methyl Ethyl Ketone / 2-Butanone)?

not established The Margin of Safety (MoS) is calculated using SCCS methodology. A MoS above 100 is generally considered safe. Use the MoS Calculator tool to calculate MoS for your specific formulation and product category.

What is the NOAEL for MEK (Methyl Ethyl Ketone / 2-Butanone)?

The NOAEL (No Observed Adverse Effect Level) for MEK (Methyl Ethyl Ketone / 2-Butanone) is 490 mg/kg bw/day based on a Short Term Toxicity study via oral route in rat. A total of 5 study endpoints are available. Source: COSMOS_DB.

Is MEK (Methyl Ethyl Ketone / 2-Butanone) classified as hazardous under GHS?

MEK (Methyl Ethyl Ketone / 2-Butanone) carries a GHS signal word of "DANGER". Hazard statements: Highly flammable liquid and vapour Causes serious eye irritation May cause respiratory irritation May cause drowsiness or dizziness Suspected of damaging fertility or the unborn child May be harmful if swallowed and enters airways. This classification is based on the ILO/WHO International Chemical Safety Card and ECHA C&L inventory data. Note: GHS classification applies to the pure substance — at cosmetic use concentrations, hazard thresholds may not be met.

Compliance Tools

Check MEK (Methyl Ethyl Ketone / 2-Butanone) compliance across multiple jurisdictions:

🔬
Ingredient Decoder
Paste a full ingredient list for instant analysis
 🌸
82 Allergen Checker
Check for EU declarable fragrance allergens
 🧪
Substance Compliance
Check compliance across 55 jurisdictions
 🧮
MoS Calculator
Calculate Margin of Safety using SCCS methodology
 ⚗️
Heavy Metal Limits
Compare limits across jurisdictions

Related Ingredients

Perfluorodimethylcyclohexane
Moderate
t-Butyl Acetate
Poor
Dipropylene Glycol Ethyl Ether
Moderate
SD Alcohol 46
Moderate
PPG-10 Butanediol
Excellent
Browse all 30,000+ ingredients →
📱

Is MEK (Methyl Ethyl Ketone / 2-Butanone) in Your Products?

Scan any product label with Piro — our free ingredient scanner. Point your camera at the ingredients list and get instant safety scores for every ingredient.

Try Piro Free →

Analyze Your Full Ingredient List

Paste any INCI list into the Decoder for instant safety analysis, or calculate the Margin of Safety for MEK (Methyl Ethyl Ketone / 2-Butanone) in your formulation.

Ingredient Decoder MoS Calculator