Toxicity of Plastic Additive 1-Hydroxycyclohexyl Phenyl Ketone (1-HCHPK) to Freshwater Microcrustaceans in Natural Water

Abstract

Various potentially toxic compounds associated with plastic (e.g., plastic additives) can enter the environment during plastic fragmentation and/or weathering. 1-Hydroxycyclohexyl phenyl ketone (1-HCHPK) is a widely used photoinitiator, e.g., in UV-radiation-curable technologies such as 3D-printing, plastic coatings and construction materials. 1-HCHPK may reach aquatic ecosystems via various waste-flows, including leaching from consumer goods. However, knowledge of its potential environmental hazard is scarce. In the present study, we addressed this data gap by assessing the acute and long-term toxicity of 1-HCHPK to freshwater microcrustaceans in environmentally relevant conditions using natural waters. The results showed that the acute toxicity of 1-HCHPK (L(E)C50) to pelagic Thamnocephalus platyurus and Daphnia magna and benthic Heterocypris incongruens ranged between 27 and 55 mg/L. Further, the long-term exposure of D. magna to low levels of 1-HCHPK (0.1 and 1.0 mg/L) did not affect ephippia hatching or organismal fitness, even in three successive daphnid generations. Thus, 1-HCHPK did not pose a hazard to the freshwater microcrustaceans at concentrations < 1 mg/L in the environmentally relevant conditions (i.e., multigenerational life cycle tests conducted in lake water at low chemical exposure concentrations). The tests employed in this study allowed for the environmentally relevant hazard assessment of emerging pollutants such as a plastic additive 1-HCHPK.

Ecotoxicological consequences of polystyrene naturally leached in pure, fresh, and saltwater: lethal and nonlethal toxicological responses in Daphnia magna and Artemia salina

“…The additives used in the manufacture of the PS could not be disclosed by the supplier. Nevertheless, several common plastic additives (Smith and Taylor, 2002;Samadi et al, 2022) have been identified as toxic to D. magna and other aquatic organisms (Thaysen et al, 2018;Schiavo et al, 2021;Song et al, 2021;Blinova et al, 2023).…”

Understanding the leaching of plastic additives and subsequent risks to ecosystems

“…On the other hand, growth and development were reduced by all the three phthalates, whereas the lipid content of Daphnia increased upon exposure to these substances. Negative effects on the lifespan of D. magna were observed with DBP at both 1 and 10 µm concentrations, and with DEP at 10 µm [125] . Blinova et al demonstrated in a laboratory assay the negative impacts of 1-Hydroxycyclohexyl phenyl ketone (1-HCHPK) on two planktonic organisms, Thamnocephalus platyurus, Daphnia magna, and the benthic organism Heterocypris incongruens.…”