Cocamidopropyl Betaine
Also known as CAPB, Cocamidopropyl betaine, Cocoamidopropyl betaine, Lauramidopropyl betaine
“CIR Expert Panel says: safe as used in cosmetics.”
COCAMIDOPROPYL BETAINE (CAPB) is a widely used amphoteric surfactant derived from coconut oil, found in shampoos, liquid soaps, and cleansers from brands including CeraVe, Dove, and Cetaphil. The CIR Expert Panel assessed CAPB as SQ (Safe Qualified) in its 2012 final report (IJT 31(S1):77-111), concluding it is safe as formulated to be non-sensitizing — a qualification directly tied to manufacturing impurities. CAPB was named Allergen of the Year in 2004 due to rising sensitization rates (3.0–7.2% in patch-test populations), but mechanistic research has established that pure CAPB is not itself the allergen: the sensitizing agents are two synthesis impurities, DMAPA (3,3-dimethylaminopropylamine) and amidoamine (the fatty acid amide intermediate). Foti et al. (2003, PMID 12786723) demonstrated that all patients allergic to commercial CAPB reacted to DMAPA and amidoamine, not to purified betaine. A 2024 Korean safety assessment (PMID 38911545) determined the margin of safety exceeds 100 at typical use concentrations (6% leave-on, 30% rinse-off), confirming safety under current industry practices. Modern high-purity manufacturing grades reduce impurity levels and substantially lower sensitization risk.
Mild amphoteric surfactant with low irritation potential relative to anionic alternatives (SDS); widely used to reduce irritancy in cleansing formulations
Functions as foam booster, viscosity modifier, and conditioning agent — multi-functional ingredient allowing formulators to reduce ingredient count
Compatible with anionic, cationic, and nonionic surfactants; enables formulation flexibility across broad pH range
2024 safety assessment confirmed margin of safety >100 at concentrations up to 6% leave-on and 30% rinse-off under current practices
- · Sensitization driven by manufacturing impurities (DMAPA and amidoamine), not pure CAPB itself: patients positive for amidoamine or DMAPA on patch test should avoid CAPB-containing products
- · Named Allergen of the Year in 2004; contact sensitization prevalence 3.0–7.2% in dermatitis patient populations on patch testing, though some reactions reflect irritancy rather than true allergy
- · SQ finding requires formulation to be non-sensitizing; impurity levels in lower-grade commercial CAPB may increase risk; high-purity grades reduce sensitization potential
CIR Quick Reference Table (12/2017, revised 07/2018) — COCAMIDOPROPYL BETAINE row: Finding=SQ, Detail='safe for use in cosmetics when for…
“Cocamidopropyl Betaine | SQ | safe for use in cosmetics when formulated to be non-sensitizing, which may be based on a quantitative risk assessment | JACT 10(1):33-52, 1991; IJT 31(S1):77-111, 2012”— QRT-122017revised072018.pdf, p. 38