Also known as: alpha-Propylene glycol, (+/-) 1,2-Propanediol, (RS)-1,2-Propanediol, dl-Propylene glycol, 3-01-00-02142 (+15 more)
INCI: PROPYLENE GLYCOL
Propylene Glycol (CAS 57-55-6) is a cosmetic humectant functioning as Diol humectant, solvent, and penetration enhancer. Attracts water from dermis. Reported NOAEL 730 mg/kg bw/day in rat (COSMOS DB); EU Regulation 1223/2009 status: permitted. Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in industrial chemical safety, pharmaceutical, and food safety data.
Diol humectant, solvent, and penetration enhancer. Attracts water from dermis and environment into epidermis. Also functions as preservative booster and freeze-point depressant.
Editorial assessment
GOOD
Preliminary editorial note — not a computed safety verdict.
US NotesCIR reviewed; considered safe. FDA GRAS for food use. Higher irritation profile at concentrations above 10-15%, particularly on compromised skin. Neither comedogenic nor occlusive at standard use levels.
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Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Propylene Glycol.
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Toxicological Studies
10 study endpoints found for Propylene Glycol. 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
730 mg/kg bw/day
oral
rat
Short Term Toxicity
COSMOS DB
NOAEL
735 mg/kg bw/day
oral
rat
Special Toxicology Study
COSMOS DB
NOAEL
1230 mg/kg bw/day
oral
rabbit
Developmental
COSMOS DB
NOAEL
1350 mg/kg bw/day
oral
cat
Short Term Toxicity
COSMOS DB
NOAEL
1550 mg/kg bw/day
oral
hamster
Developmental
COSMOS DB
NOAEL
1600 mg/kg bw/day
oral
mouse
Developmental
COSMOS DB
NOAEL
2000 mg/kg bw/day
oral
dog
Chronic
COSMOS DB
NOAEL
2100 mg/kg bw/day
oral
rat
Subchronic
COSMOS DB
NOAEL
2450 mg/kg bw/day
oral
rat
Chronic
COSMOS DB
NOAEL
2750 mg/kg bw/day
oral
cat
Subchronic
COSMOS DB
GHS Hazard Classification
Globally Harmonized System classification per ECHA C&L inventory and ILO/WHO International Chemical Safety Cards.
Hazard Statements
No hazard classification according to GHS criteria
Short-term Exposure Effects
The substance is mildly irritating to the eyes and respiratory tract. Ingestion of large amounts could cause metabolic acidosis.
Sensitization Profile
Contact sensitization data for Propylene Glycol based on clinical patch test studies and IFRA standards.
Sensitization Rate
moderate
Allergen Class
botanical
EU Allergen Listed
no
Patch Test Positive Rate
2.0%
Cross-reactivity Group
glycol-group
Reaction Type
contact-dermatitis
Source: IVDK; ESSCA; NACDG
Dermal Penetration Profile
Skin absorption and penetration characteristics of Propylene Glycol, relevant to systemic exposure and MoS calculations.
Absorption %
15-30%
Penetration Level
epidermis
Penetration Depth
epidermis
Molecular Weight
76.1 Da
Log P
-0.92
Systemic Absorption
yes
Topical Bioavailability
10-25%
Safety Margin Factor
high
Source: SCCS Opinion
EPA ToxValDB — Toxicity Values
10 toxicity values from EPA ToxValDB (aggregated from CCTE, HPV, ToxRefDB, IRIS, and other regulatory dossiers).
Endpoint
Value
Species
Route
Duration
Source
NOEL
=2500 mg/kg-day
Rat
oral
chronic
EFSA
NOEL
=2500 mg/kg-day
Rat
oral
chronic
EFSA
LEL
=80919.4 mg/m3
Human
inhalation
-
DOE Protective Action Criteria
NOEL
=2500 mg/kg-day
Rat
oral
chronic
EFSA
ADI
<=25 mg/kg
Human
oral
-
WHO/JECFA
MRL
=0.0280106 mg/m3
Human
inhalation
-
ATSDR MRLs
NOEL
=5 %
Mouse
oral
chronic
ECOTOX
NOEL
=10000 mg/kg-day
Mouse
oral
short-term (developmental)
ECOTOX
LC50
>317042 mg/m3
Rabbit
inhalation
-
ECHA
LC50
>44900 mg/m3
Rat
inhalation
-
ECHA
Sensitization AOP Dashboard
Adverse Outcome Pathway data across 5 assays (DPRA, KeratinoSens, hCLAT, LLNA, NESIL) aggregated from public sources.
DPRA Cys %
0%
DPRA Lys %
0.6%
KeratinoSens IC50
2000 µM
hCLAT CV75
916.65 µg/mL
LLNA EC3
100%
NESIL
9300 µg/cm²
LLNA: NC (non-sensitizer)GHS: not classifiedHuman: positive
Source: LLNA: Gerberick et al. (2005); DPRA: Urbisch et al. 2015 [DOI:10.1016/j.yrtph.2014.12.008] | Bauch et al. 2012 [DOI:10.1016/j.yrtph.2012.05.013]; KS: Emter et al. 2010 [DOI:10.1016/j.taap.2010.03.009] | Bauch et al. 2012 [DOI:10.1016/j.yrtph.2012.05.013]; hCLAT: Bauch et al. 2012 [DOI:10.1016/j.yrtph.2012.05.013] | Ashikaga et al. 2010 [DOI:10.1177/026119291003800403]; HPPT: [27] Kligman AM (1966): https://doi.org/10.1038/jid.1966.160
HRIPT Human Patch Test Studies
4 human repeat insult patch tests aggregated from dermatological literature.
Test Type
N
Sensitized
Dose µg/cm²
NESIL µg/cm²
Potency
HMT
-
0
15517.24
-
-
HRIPT
-
0
9300.02
-
-
HRIPT
-
0
41850.08
-
-
OECD_DA_Human
-
0
-
-
Non-sensitizer
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Full
Tonnage Band
100,000 - 1,000,000 tonnes
Substance Type
SUBSTANCE; GROUP
SVHC Candidate
No
Typical Use Concentrations
Reported concentration ranges per product category from SCCS/CIR/industry sources.
EU Regulated in Personal CareEU Restricted for Children (Cosmetics)IFRA Fragrance Transparency ListEPA Safer Chemical Ingredients List (SCIL)FDA Substances Added to Food (EAFUS)Consumer Product Chemical
Editorial summary
Preliminary editorial summary for Propylene Glycol — not a computed safety verdict. See the sourced toxicological data above.
air; detected; emissions; Europe; Vehicle - car interior - auto air freshenerdetected; Europe; Vehicle - car interiordetected; Europe; Personal care - linimentdetected; Europe; Other direct contact consumer goodsair; detected; emissions; Europe; Other direct contact consumer goodsair; detected; emissions; Europe; Other direct contact consumer goodsEurope; Personal care - linimentSCIL (9/2019)artificial_saliva; detected; emissions; Europe; Toys and children's productsconsumer_productCleaning products and household care - laundry and fabric treatment - laundry detergent; EuropeCleaning products and household care - shoes; EuropeCleaning products and household care - shoes; Europefracking; wateractive_ingredient; Europe; Pesticidesair; detected; emissions; Europe; Toys and children's productsCleaning products and household care - laundry and fabric treatment - laundry stain remover; detected; Europeactive_ingredient; Pesticides
Cross-Vertical Safety Context
Same-CAS public records found in pharmaceutical and food safety data.
SOURCEChEMBL / DrugCentral / FAERSDB_PHARMA CAS match
Pharmaceutical Data
Same-CAS rows from the pharmaceutical spoke database.
Propylene Glycol has a safety rating of "GOOD" in our database. EU status: permitted. US status: permitted. 10 toxicological study endpoint(s) are available in our database.
Is Propylene Glycol allowed in the EU?
Propylene Glycol EU regulatory status: permitted. This is based on EU Regulation 1223/2009 and its amendments.
What does Propylene Glycol do in cosmetics?
Propylene Glycol functions as: Diol humectant, solvent, and penetration enhancer. Attracts water from dermis and environment into epidermis. Also functions as preservative booster and freeze-point depressant.. It is classified as a Humectant in our database. CAS number: 57-55-6.
What is the NOAEL for Propylene Glycol?
The NOAEL (No Observed Adverse Effect Level) for Propylene Glycol is 730 mg/kg bw/day based on a Short Term Toxicity study via oral route in rat. A total of 10 study endpoints are available. Source: COSMOS DB.
Is Propylene Glycol used outside cosmetics?
Propylene Glycol also appears in industrial chemical safety, pharmaceutical, and food safety data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Compliance Tools
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