Poor Cosmetic Ingredient NOAEL Data

Perfluorohexylethyl Triethoxysilane

INCI: PERFLUOROHEXYLETHYL TRIETHOXYSILANE

CAS Number
51851-37-7
Function
Binder, skin conditioning
Safety Rating
POOR

Regulatory Status

๐Ÿ‡ช๐Ÿ‡บ EU Status prohibited
๐Ÿ‡บ๐Ÿ‡ธ US Status restricted
US Notes FDA flagged as having a potential safety concern in body lotion at the highest reported concentration (MoCRA PFAS report, Dec 2025)

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

Safety Data

Margin of Safety (MoS)
adequate
Dermal Absorption
moderate
Sensitization
moderate

Calculate MoS for your specific formulation with the MoS Calculator.

Toxicological Studies

1 study endpoint found for Perfluorohexylethyl Triethoxysilane. 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 50 mg/kg bw/day oral rat oral REACH

Expert Verdict

Tier 1 high-risk PFAS flagged by FDA for safety concern; triethoxysilane group hydrolyzes to release ethanol and silanol; confirmed PFHxA precursor.

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Concern Level: High

Frequently Asked Questions

Is Perfluorohexylethyl Triethoxysilane safe in cosmetics?

Tier 1 high-risk PFAS flagged by FDA for safety concern; triethoxysilane group hydrolyzes to release ethanol and silanol; confirmed PFHxA precursor. The EU classifies Perfluorohexylethyl Triethoxysilane as "prohibited". Safety rating: POOR. 1 toxicological study endpoint(s) are available in our database.

Is Perfluorohexylethyl Triethoxysilane allowed in the EU?

Perfluorohexylethyl Triethoxysilane EU regulatory status: prohibited. This is based on EU Regulation 1223/2009 and its amendments.

What does Perfluorohexylethyl Triethoxysilane do in cosmetics?

Perfluorohexylethyl Triethoxysilane functions as: Binder, skin conditioning. It is classified as a cosmetic ingredient in our database. CAS number: 51851-37-7.

What is the Margin of Safety for Perfluorohexylethyl Triethoxysilane?

adequate 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 Perfluorohexylethyl Triethoxysilane?

The NOAEL (No Observed Adverse Effect Level) for Perfluorohexylethyl Triethoxysilane is 50 mg/kg bw/day based on a oral study via oral route in rat. Source: REACH.

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