Excellent Preservative NOAEL Data GHS Classified Sensitization Data Dermal Penetration

Sodium Benzoate

INCI: SODIUM BENZOATE

CAS Number
532-32-1
Function
preservative
Safety Rating
EXCELLENT

Regulatory Status

🇪🇺 EU Status restricted
EU Max Conc. 0.5% as benzoic acid equivalent
🇺🇸 US Status permitted
US Notes Permitted; GRAS for food use. No US-specific cosmetic concentration cap. Very low sensitization rate — suitable for sensitive-skin and baby formulations. pH-dependent: active as undissociated benzoic acid below pH 5.5. Potassium sorbate + sodium benzoate combination system preferred for clean/organic acid preservation.

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

Safety Data

Margin of Safety (MoS)
not established
Dermal Absorption
negligible
Sensitization
none

Calculate MoS for your specific formulation with the MoS Calculator.

Toxicological Studies

10 study endpoints found for Sodium Benzoate. 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 1000 mg/kg bw/day oral rat Short Term Toxicity COSMOS_DB
NOAEL 1000 mg/kg bw/day oral rat Short Term Toxicity COSMOS_DB
NOAEL 5000 mg/kg bw/day oral rat Short Term Toxicity COSMOS_DB
NOAEL 1000 mg/kg bw/day oral rat Short Term Toxicity COSMOS_DB
NOAEL 8000 mg/kg bw/day oral rat Subchronic COSMOS_DB
NOAEL 1000 mg/kg bw/day oral dog Chronic COSMOS_DB
NOAEL 510 mg/kg bw/day oral rat Developmental COSMOS_DB
NOAEL 175 mg/kg bw/day oral mouse Developmental COSMOS_DB
NOAEL 175 mg/kg bw/day oral rat Developmental COSMOS_DB
NOAEL 300 mg/kg bw/day oral hamster Developmental COSMOS_DB

GHS Hazard Classification

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

Short-term Exposure Effects
The substance is mildly irritating to the eyes.

Sensitization Profile

Contact sensitization data for Sodium Benzoate based on clinical patch test studies and IFRA standards.

Sensitization Rate
low
Allergen Class
preservative
EU Allergen Listed
no
Patch Test Positive Rate
0.3%
Cross-reactivity Group
benzoate-group
Reaction Type
contact-dermatitis

Source: ESSCA; IVDK; NACDG

Dermal Penetration Profile

Skin absorption and penetration characteristics of Sodium Benzoate, relevant to systemic exposure and MoS calculations.

Absorption %
2-5%
Penetration Level
surface
Penetration Depth
stratum corneum
Molecular Weight
144.1 Da
Log P
-2.3
Systemic Absorption
minimal
Topical Bioavailability
1-3%
Safety Margin Factor
low
Vehicle Dependent
Yes — absorption varies by formulation

Source: CIR

Expert Verdict

Excellent preservative for sensitive-skin products with very low sensitization rates. Active as benzoic acid below pH 5.5 with anti-yeast and anti-bacterial spectrum. Sodium benzoate + potassium sorbate combination at pH <5.5 provides validated low-sensitization alternative to phenoxyethanol-based systems. Compatible with sensitive-skin formulations (pH 5.0–5.5). EU Annex V listed at ≤0.5% as benzoic acid equivalent.

⚠️
Concern Level: None

Regulatory Flags

preservative eu-annex-v organic-acid very-low-sensitization ph-dependent sensitive-skin-suitable baby-safe clean-label gras synergistic-with-potassium-sorbate ph-5.5-optimal eu_children_restricted epa_safer_alternative ifra_fragrance fda_food_additive

Frequently Asked Questions

Is Sodium Benzoate safe in cosmetics?

Excellent preservative for sensitive-skin products with very low sensitization rates. Active as benzoic acid below pH 5.5 with anti-yeast and anti-bacterial spectrum. Sodium benzoate + potassium sorbate combination at pH <5.5 provides validated low-sensitization alternative to phenoxyethanol-based systems. Compatible with sensitive-skin formulations (pH 5.0–5.5). EU Annex V listed at ≤0.5% as benzoic acid equivalent. The EU classifies Sodium Benzoate as "restricted". Safety rating: EXCELLENT. 10 toxicological study endpoint(s) are available in our database.

Is Sodium Benzoate allowed in the EU?

Sodium Benzoate EU regulatory status: restricted. Maximum allowed concentration: 0.5% as benzoic acid equivalent. This is based on EU Regulation 1223/2009 and its amendments.

What does Sodium Benzoate do in cosmetics?

Sodium Benzoate functions as: preservative. It is classified as a Preservative in our database. CAS number: 532-32-1.

What is the Margin of Safety for Sodium Benzoate?

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 Sodium Benzoate?

The NOAEL (No Observed Adverse Effect Level) for Sodium Benzoate is 1000 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.

Compliance Tools

Check Sodium Benzoate compliance across multiple jurisdictions:

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Ingredient Decoder
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82 Allergen Checker
Check for EU declarable fragrance allergens
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Substance Compliance
Check compliance across 55 jurisdictions
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MoS Calculator
Calculate Margin of Safety using SCCS methodology
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Heavy Metal Limits
Compare limits across jurisdictions

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