Cosmetic Preservatives: Hazardous Micropollutants in Need of Greater Attention?

Abstract

In recent years, personal care products (PCPs) have surfaced as a novel class of pollutants due to their release into wastewater treatment plants (WWTPs) and receiving environments by sewage effluent and biosolid-augmentation soil, which poses potential risks to non-target organisms. Among PCPs, there are preservatives that are added to cosmetics for protection against microbial spoilage. This paper presents a review of the occurrence in different environmental matrices, toxicological effects, and mechanisms of microbial degradation of four selected preservatives (triclocarban, chloroxylenol, methylisothiazolinone, and benzalkonium chloride). Due to the insufficient removal from WWTPs, cosmetic preservatives have been widely detected in aquatic environments and sewage sludge at concentrations mainly below tens of µg L-1. These compounds are toxic to aquatic organisms, such as fish, algae, daphnids, and rotifers, as well as terrestrial organisms. A summary of the mechanisms of preservative biodegradation by micro-organisms and analysis of emerging intermediates is also provided. Formed metabolites are often characterized by lower toxicity compared to the parent compounds. Further studies are needed for an evaluation of environmental concentrations of preservatives in diverse matrices and toxicity to more species of aquatic and terrestrial organisms, and for an understanding of the mechanisms of microbial degradation. The research should focus on chloroxylenol and methylisothiazolinone because these compounds are the least understood.

Mitigation of Triclocarban Inhibition in Microbial Electrolysis Cell-Assisted Anaerobic Digestion

“…Chlorine substituents control the lipid solubility, making it easy for TCC to cross the cell membrane and bind to aryl hydrocarbon receptors. , Therefore, dechlorination of TCC to DCC would theoretically result in a decrease of toxicity. Although corresponding experimental data is lacking in previous studies, Wang et al predicted that the acute and chronic toxicities of DCC are significantly lower than those of TCC based on the Ecological Structure Activity Relationships (ECOSAR) model. , …”

“…Although corresponding experimental data is lacking in previous studies, Wang et al predicted that the acute and chronic toxicities of DCC are significantly lower than those of TCC based on the Ecological Structure Activity Relationships (ECOSAR) model. 45,46 3.4. Shift in Microbial Community.…”

Determination and Analysis of Thermodynamic Properties of Methyl Methylanthranilate Isomers

“…In this process, the enthalpy change of those reactions, ∆ r H • m (g), were calculated using the computational absolute standard enthalpies, H conformation composition of each one) through Equation (1). Then, with the knowledge of experimental gas-phase standard molar enthalpies of formation of the auxiliary molecules involved in the gas-phase hypothetical reactions, the estimated values of ∆ f H • m (g) were calculated using Equation (2). The data pertaining to these chemical structures are presented in Supplementary Materials (Table S5).…”

“…1 The quoted uncertainty was determined by considering the combined standard uncertainty, which includes the contribution from the calibration with benzoic acid and the auxiliary compound (when used), as well as the coverage factor k = 2 (corresponding to a 0.95 confidence level) [26]; 2 The quoted uncertainty was calculated by considering the combined standard uncertainty, which takes into account the contribution of the species participating in the respective combustion reactions Equation (3), and the coverage factor k = 2 (corresponding to a 0.95 confidence level) [26].…”

“…However, these substances can have negative environmental impacts as they persist and accumulate in various ecosystems due to the inefficiency of conventional wastewater treatment processes in removing them from treated water before their discharge into effluents. Environmentalists have raised concerns about the potential long-term effects of fragrance accumulation on ecosystems [ 1 , 2 , 3 , 4 , 5 , 6 ]. In cases where conventional treatments are unable to eliminate micropollutants, closer environmental risk monitoring of fragrances prior to their commercial use can be an effective solution.…”