First Evidence of Hindered Amine Light Stabilizers As Abundant, Ubiquitous, Emerging Pollutants in Dust and Air Particles: A New Concern for Human Health

Abstract

Hindered amine light stabilizers (HALSs) represent a crucial class of polymer additives that are extensively used in plastics and other polymeric materials. However, their environmental presence and related exposure risks have until now remained unexplored. This study addressed this critical knowledge by examining dust and air particles collected in South China, utilizing a comprehensive analytical approach to identify and quantify nine monomeric HALSs. A total of seven of the nine studied HALSs were detected in the samples, with bis(2,2,6,6tetramethyl-4-piperidyl) sebacate (Tinuvin 770) and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (HS-508) identified as the most abundant and widespread pollutants. Median total concentrations of HALSs ranged from 417 to 8,830 ng/g in urban dust samples and from 28.6 to 70.9 pg/m 3 in urban air particles. Notably, dust concentrations of HALSs significantly exceeded those of traditional well-known light stabilizers such as UV absorbers. Human exposure assessment indicated that in contrast to air inhalation dust ingestion represented a more substantial exposure pathway owing to the relatively low volatility of these newly identified chemicals. Predictive modeling suggests that many of the examined HALSs exhibited characteristics of persistence, high toxicity, or strong potential for long-range transport, underscoring their hazardous nature. This study represents the first comprehensive investigation into the prevalence of HALSs as a class of emerging pollutants widespread in the environment, necessitating heightened attention and further research in the future.

Correspondence on “First Evidence of Hindered Amine Light Stabilizers as Abundant, Ubiquitous, Emerging Pollutants in Dust and Air Particles: A New Concern for Human Health”

“…52829-07-9 is not a sensitizer. This result is further supported by an additional optimization study conducted according to established guidelines …”

“…52829-07-9 has been reported, this application route does not mimic realistic exposure conditions, and the conclusions should be appropriately bounded in the current paper and balanced with other available information. The REACH registration dossier includes several GLP and OECD guideline-conforming studies after repeated exposure . In the Extended-One-Generation Study, CAS Registry No.…”

Rebuttal to Correspondence on “First Evidence of Hindered Amine Light Stabilizers As Abundant, Ubiquitous, Emerging Pollutants in Dust and Air Particles: A New Concern for Human Health”

“…HALSs make up a class of widely used polymer additives in plastics and other polymeric materials. In our study, we examined nine HALSs and found seven of them to be present in the environment . Model predictions on PBT of HALSs suggest that some HALSs are suspected hazardous chemicals .…”

“…In our study, we examined nine HALSs and found seven of them to be present in the environment . Model predictions on PBT of HALSs suggest that some HALSs are suspected hazardous chemicals . However, Malone and Leed raised concerns about the predictions on PBT of HALSs and their possible hazards.…”

“…We appreciate the comments received from Malone and Leed on our study that reported the environmental occurrence of hindered amine light stabilizers (HALSs) in dust and air particles from South China and the predictions about the potential persistence, bioaccumulation, and toxicity (PBT) of HALSs . HALSs make up a class of widely used polymer additives in plastics and other polymeric materials.…”