Butyloctyl Salicylate
Also known as 2-Butyloctyl salicylate, 2-Butyloctyl 2-hydroxybenzoate, HallBrite BHB
“CIR Expert Panel says: safe as used in cosmetics.”
Butyloctyl Salicylate (2-butyloctyl 2-hydroxybenzoate; CAS 190085-41-7; C19H30O3) is a branched-chain ester of salicylic acid used primarily as an emollient and solvent in cosmetic formulations, including sunscreens where it improves spreadability and can solubilize organic UV filters such as avobenzone. The CIR Expert Panel assessed butyloctyl salicylate as part of a group safety assessment of 17 salicylates (IJT 22(Suppl 3):1-108, 2003; amended 2025), concluding SQ (safe qualified): safe when formulated to avoid irritation and when sun sensitivity directions are included if increased photosensitivity is expected. Key toxicology data from the 2003 assessment include little acute dermal toxicity, no ocular irritation in rabbits, and no sensitization in guinea pig maximization testing. A 2024 ADME read-across study (PMID 38539266) noted that butyloctyl salicylate exhibits markedly different absorption, distribution, metabolism, and excretion properties compared to homosalate and octisalate UV filters, indicating it is not a suitable read-across analog for those UV filters — this finding is consistent with its classification as a skin-conditioning ester rather than a primary UV-filter active.
Emollient and solvent: improves texture and spreadability of cosmetic formulations, particularly mineral and hybrid sunscreens
UV filter solubilizer: aids dissolution of avobenzone and similar organic UV filters, improving SPF performance of sunscreen formulations without itself being a UV filter active
Skin conditioning: functions as a hair and skin conditioning agent at reported use concentrations of 0.5–5%
Favorable irritation and sensitization profile: no ocular irritation and no sensitization in guideline animal studies (CIR 2003 assessment)
- · Distinct ADME profile from UV filter salicylates (homosalate, octisalate): not a suitable read-across analog; its safety cannot be inferred from UV filter assessments
Sun sensitivity qualification (SQ): CIR requires formulations either avoid increasing sun sensitivity or include directions for daily sun protection use — this is a labeling/formulation discipline requirement, not a concentration cap
Salicylate class: potential contribution to cumulative salicylate body burden when combined with other topical salicylate-containing products, though no specific systemic concern is documented at cosmetic-use concentrations for this ester
CIR Quick Reference Table (12/2017, revised 07/2018) — Butyloctyl Salicylate row: Finding=SQ, Citation=IJT 22(3):1-108
“Butyloctyl Salicylate SQ safe when formulated to avoid irritation and to avoid increasing sun sensitivity, or when increased sun sensitivity would be expected, directions for use include the daily use of sun protection. IJT 22(3):1-108”— QRT-122017revised072018.pdf, p. 15