Is 4-Hydroxybenzoic Acid safe in cosmetics?
4-Hydroxybenzoic Acid has a safety rating of "EXCELLENT" in our database. EU status: restricted. US status: permitted. 1 toxicological study endpoint(s) are available in our database.
4-Hydroxybenzoic Acid
Also known as: p-Hydroxybenzoic acid, 4-Carboxyphenol, EINECS 202-804-9, Acido p-idrossibenzoico, Kyselina 4-hydroxybenzoova (+10 more)
INCI: 4-HYDROXYBENZOIC ACID
4-Hydroxybenzoic Acid (CAS 99-96-7) is a cosmetic preservative functioning as Preservative, pH Balancer. Reported NOAEL =1043 mg/kg bw/day in Rat (ToxValDB_ECHA_IUCLID); EU Regulation 1223/2009 status: restricted, max 0.4% (as acid) single; 0.8% mixtures (Annex V/12). Propyl/butylparaben sum ≤0.14%. Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in industrial chemical safety and pharmaceutical data.
View industrial chemical safety profile for CAS 99-96-7 →
Auto-generated CPSR Part A draft with source citations
Cross-Vertical Regulatory Divergence
4-Hydroxybenzoic Acid is classified GHS Danger (H315, H318, H319, H335) in the chemicals database but is restricted in EU cosmetics at max 0.4% (as acid) single; 0.8% mixtures (Annex V/12). Propyl/butylparaben sum ≤0.14%.
Source: Cosmetics: ingredients.eu_status/eu_max; Chemicals: ghs_classifications.signal_word/hazard_statement_code
Function
Preservative, pH Balancer
Safety Rating
EXCELLENT
Chemistry & Identifiers
IUPAC Name
4-hydroxybenzoic acid
InChIKey
FJKROLUGYXJWQN-UHFFFAOYSA-N
Regulatory Status
EU EU Status
restricted
EU Max Conc.
0.4% (as acid) single; 0.8% mixtures (Annex V/12). Propyl/butylparaben sum ≤0.14%
US US Status
permitted
US Notes
CIR 2019 safe. Methylparaben/propylparaben GRAS for food.
For full compliance data across multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for 4-Hydroxybenzoic Acid.
Calculate MoS for your specific formulation with the MoS Calculator.
Toxicological Studies
1 study endpoint found for 4-Hydroxybenzoic Acid. 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 | =1043 mg/kg bw/day | oral | Rat | reproduction developmental | ToxValDB_ECHA_IUCLID |
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 |
|---|---|---|---|---|---|
| LOEL | =200 mg/kg-day | Rat | oral | subchronic | ECHA IUCLID |
| LOEL | =1000 mg/kg-day | Rat | oral | subchronic | ECHA IUCLID |
| NOAEL | >=1000 mg/kg-day | Rat | oral | subchronic | ECHA IUCLID |
| NOAEL | =1043 mg/kg-day | Rat | oral | - | ECHA IUCLID |
| NOAEL | >1043 mg/kg-day | Rat | oral | - | ECHA IUCLID |
| NOEL | >1000 mg/kg-day | Rat | oral | - | ECHA IUCLID |
| NOEL | =60 mg/m3 | Rat | inhalation | short-term | ECHA IUCLID |
| NOEL | =40 mg/kg-day | Rat | oral | subchronic | ECHA IUCLID |
| NOEL | >=100 mg/kg-day | Mouse | injection | short-term | ECHA IUCLID |
| NOEL | >200 mg/kg-day | Rat | oral | - | ECHA IUCLID |
Sensitization AOP Dashboard
Adverse Outcome Pathway data across 5 assays (DPRA, KeratinoSens, hCLAT, LLNA, NESIL) aggregated from public sources.
DPRA Cys %
1.7%
DPRA Lys %
0.7%
KeratinoSens IC50
2000 µM
hCLAT CV75
1333.35 µg/mL
LLNA EC3
25%
NESIL
6250 µg/cm²
LLNA: Weak (1B)
GHS: 1B
Source: LLNA: https://echa.europa.eu/it/registration-dossier/-/registered-dossier/15944/7/5/2 | Gerberick et al. (2005); DPRA: Bauch et al. 2012 [DOI:10.1016/j.yrtph.2012.05.013] | Gerberick et al. 2007 [DOI:10.1093/toxsci/kfm064]; KS: Urbisch et al. 2015 [DOI:10.1016/j.yrtph.2014.12.008] | 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]
Endocrine Disruptor Evidence (Expanded)
Cross-referenced EDC classifications, mechanism data, and dose-response evidence from EDLists, SIN List, and cosmetic-specific detail sources.
Cosmetic-Specific Mechanism
Category: paraben
Receptor targets: ERα (very weak)
LOEC: 1 mM
EU status: allowed
very weak agonist (paraben metabolite)
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Full
Tonnage Band
1,000 - 10,000 tonnes
Substance Type
SUBSTANCE
SVHC Candidate
No
PubChem Annotations
Safety and regulatory annotations from PubChem (NCBI) aggregated sources.
Regulatory (4)
JECFA Number
957
Source: Joint FAO/WHO Expert Committee on Food Additives (JECFA)
JECFA Evaluation
4-HYDROXYBENZOIC ACID | 2001 | No safety concern at current levels of intake when used as a flavouring agent | TRS 909-JECFA 57/84 | FAS 48-JECFA 57/273
Source: Joint FAO/WHO Expert Committee on Food Additives (JECFA)
JECFA Evaluation
p-SALICYLIC ACID | 2001 | No safety concern at current levels of intake when used as a flavouring agent | TRS 909-JECFA 57/84 | FAS 48-JECFA 57/273
Source: Joint FAO/WHO Expert Committee on Food Additives (JECFA)
JECFA Evaluation
p-HYDROXYBENZOIC ACID | 2001 | No safety concern at current levels of intake when used as a flavouring agent | TRS 909-JECFA 57/84 | FAS 48-JECFA 57/273
Source: Joint FAO/WHO Expert Committee on Food Additives (JECFA)
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Flavouring and nutrient
Fragrance
Preservative
Regulatory List Membership (3)
EU Regulated in Personal Care
FDA Substances Added to Food (EAFUS)
EU CosIng Cosmetics Ingredient Database
Expert Verdict
Expert safety assessment and concern-level summary for 4-Hydroxybenzoic Acid.
Regulatory Flags
EU_RESTRICTED
fda_food_additive
eu_cosing_listed
jecfa_safe
NOAEL Studies Summary
View details ->Public NOAEL study rows linked to 4-Hydroxybenzoic Acid by CAS number or substance name.
Studies
4
Lowest NOAEL
1043 mg/kg bw/day
Highest NOAEL
1043 mg/kg bw/day
ToxValDB_ECHA_IUCLID
ECHA_REACH_reach_study_results_dossiers_23-05-2023.zip
Known Synonyms
p-Hydroxybenzoic acid
4-Carboxyphenol
EINECS 202-804-9
Acido p-idrossibenzoico
Kyselina 4-hydroxybenzoova
p-Oxybenzoesaure
UNII-JG8Z55Y12H
4-Hydroxy-benzoate
4-Hydroxy-benzoesaeure
4-Hydroxy-benzoic acid
4-Hydroxybenzoate
p-Hydroxy-Benzoate
p-Hydroxy-Benzoic acid
p-Hydroxybenzoate
p-Salicylate
Chemical Function
Preservative
Fragrance
Flavouring and nutrient
Regulatory Lists
Europe; Personal care
consumer_product; Europe
consumer_product; Europe
Europe
children; WA Children's Safe Product Act (4/2020)
food_additive; Substances Added to Food (formerly EAFUS) (2/2019)
Canada; pharmaceutical
active_ingredient; Europe; Pesticides
children
children
children
Australian Status
AICIS status: listed
Cross-Vertical Safety Context
Same-CAS public records found in pharmaceutical data.
SOURCE
ChEMBL / DrugCentral / FAERS
DB_PHARMA CAS match
Pharmaceutical Data
Same-CAS rows from the pharmaceutical spoke database.
Compound
PARABEN
ChEMBL ID
CHEMBL441343
Frequently Asked Questions
Is 4-Hydroxybenzoic Acid allowed in the EU?
4-Hydroxybenzoic Acid EU regulatory status: restricted. Maximum allowed concentration: 0.4% (as acid) single; 0.8% mixtures (Annex V/12). Propyl/butylparaben sum ≤0.14%. This is based on EU Regulation 1223/2009 and its amendments.
What does 4-Hydroxybenzoic Acid do in cosmetics?
4-Hydroxybenzoic Acid functions as: Preservative, pH Balancer. It is classified as a Preservative in our database. CAS number: 99-96-7.
What is the NOAEL for 4-Hydroxybenzoic Acid?
The NOAEL (No Observed Adverse Effect Level) for 4-Hydroxybenzoic Acid is =1043 mg/kg bw/day based on a reproduction developmental study via oral route in Rat. Source: ToxValDB_ECHA_IUCLID.
Is 4-Hydroxybenzoic Acid used outside cosmetics?
4-Hydroxybenzoic Acid also appears in industrial chemical safety and pharmaceutical data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Does 4-Hydroxybenzoic Acid have different safety status in cosmetics vs industrial chemicals?
4-Hydroxybenzoic Acid is classified GHS Danger (H315, H318, H319, H335) in the chemicals database but is restricted in EU cosmetics at max 0.4% (as acid) single; 0.8% mixtures (Annex V/12). Propyl/butylparaben sum ≤0.14%.
Compliance Tools
Check 4-Hydroxybenzoic Acid 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 multiple jurisdictions
MoS Calculator
Calculate Margin of Safety using SCCS methodology
Heavy Metal Limits
Compare limits across jurisdictions
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