Phenyl salicylate: Properties,safety usage and application research

Introduction

Phenyl salicylate is a fragrance ingredient used in many fragrance compounds. It may be found in fragrances used in decorative cosmetics, fine fragrances, shampoos, toilet soaps and other toiletries as well as in non-cosmetic products such as household cleaners and detergents. Its use worldwide is in the region of less than 0.1 metric tonnes per annum.[1]Phenyl salicylate has been employed industrially as a sunscreen enteric coating for delayed action tablets and plasticizer, and in a variety of other pharmaceutical applications similar to those of aspirin.[2] According to research statistics,the global phenyl salicylate market sales reached $31 million in 2023, and is expected to reach $42 million by 2030. In the future, the increasing phenyl salicylate will be produced and used, thus its effects on organisms from its prolonged exposure should not be ignored. Although the level of phenyl salicylate in the environment have not been reported, salicylic acid UV absorbers have been detected in sewage sludge from wastewater treatment plants at levels up to 3118 ng/g dw , in surface water along the Danube River at levels up to 32 to 44 ng/L, and in sediment at levels up to 79 to 244 ng/g dw. The content of UV-absorbents in surface water of rivers and lakes in Japan can reach up to 5μg/L, with salicylic acid UV absorbers predominating. Surprisingly, it was found to accumulate specifically in the liver, muscle, and gills of fish. Therefore,it is necessary to pay attention to phenyl salicylate induced damage in the living organisms.[3]

Physical properties

Formula: C₁₃H₁₀O₃.

Molecular weight: 214.22.

Physical form: White granular crystal.（Figure 1）

Boiling point: 172℃@12mmHg.

Flash point>200℉；CC.

LogKow (calculated) 3.82.

Vapor pressure (calculated) 0.0000627 mmHg 25℃.

Usage

The maximum skin level that results from the use of phenyl salicylate in formulae that go into fine fragrances has not been reported. A default value of 0.02% is used,assuming use of the fragrance oil at levels up to 20% in the final product. The 97.5‰ use level in formulae for use in cosmetics in general has not been reported. As such,a default value of 0.02% is used to calculate a maximum daily exposure on the skin of 0.0005 mg/kg for high end users of these products (see Table 1).[1]

Neurotoxicity on wildlife 

In this study, Liu and his colleagues exposed zebrafish embryos at 4 hours post-fertilization (hpf) to 0.025, 0.05, 0.1, 0.25, 0.5, and 1.0 mg/L of phenyl salicylate up to 144 hpf and found its developmental- and neuro-toxicity. Specifically, a dose-dependent increase in mortality and malformation in zebrafish were revealed. Phenyl salicylate also adversely affected the development of monoaminergic neurons, cerebral blood vessels, and the blood-brain barrier (BBB), as well as induced cerebral hemorrhages and locomotion change. RNA-sequencing results combined with verification data showed that phenyl salicylate downregulated the expression of the N-myc downstream regulated gene-1 (ndrg1), caused myelin damage in zebrafish, and then increased expression of beta-secretase 1 (bace1), which ultimately led to early Alzheimer's disease (AD)-like symptoms, including BBB leakage, bleeding in the brain, and upregulation of the glial fibrillary acidic protein gene (gfap) and cholinergic system-related gene (chrna7a). In conclusion, phenyl salicylate exposure triggered developmental toxicity and neurotoxicity in zebrafish, which has a potential risk for the development of AD. Given the effects of phenyl salicylate exposure to ecosystem, the safety usage limit should be treated with caution.[3]

Application example

Polylactic acid-cellulose acetate film modified by phenyl salicylate

The polylactic acid composite films were successfully fabricated via the technique of solvent casting using cellulose acetate (20%, wt) as the reinforcing material and phenyl salicylate as the ultraviolet (UV) absorbent and antibacterial agent. Polylactic acid-cellulose acetate-phenyl salicylate composite films displayed complete absorption effect at the region of UV-C (280-100 nm) and UV-B (315-280 nm), and more than 95% UV absorption effect at the region of UV-A (400-315 nm). These results indicate that the UV shielding performance of the composite films could be significantly improve by addition of phenyl salicylate. Moreover, the addition of 20% phenyl salicylate could improve the steam resistance, mechanical properties and thermal stability of the films, and the composite films had also better antibacterial activity against Escherichia coli. The composite films could reduce the decay rate of fresh lilies and extend their storage time. The degradation characteristics of the films were explored in the natural environment and the laboratory level, which provided application prospect for the development of degradable food packaging materials with anti-ultraviolet and anti-bacteria effect.[4]

References

1.Lapczynski A, Jones L, McGinty D, Bhatia SP, Letizia CS, Api AM. Fragrance material review on phenyl salicylate. Food Chem Toxicol. 2007;45 Suppl 1:S472-S476. doi:10.1016/j.fct.2007.09.062

2.Rutledge JM, Schulman SG. Fluroescence of phenyl salicylate. Anal Chim Acta. 1975;75(2):449-452. doi:10.1016/s0003-2670(01)85371-x

3.Liu S, Li X, Jiao S, et al. Phenyl salicylate induces neurotoxicity and early Alzheimer's disease-like symptoms through ndrg1-regulated myelin damage, increasing bace1 in zebrafish. Sci Total Environ. 2025;965:178664. doi:10.1016/j.scitotenv.2025.178664

4.Liang L, Chen H. Development and characterization of biodegradable ultraviolet protective and antibacterial polylactic acid-cellulose acetate film modified by phenyl salicylate. Int J Biol Macromol. 2022;211:85-93. doi:10.1016/j.ijbiomac.2022.05.055