Comprehensive risk assessment of the inhalation of plasticizers from the use of face masks

Disposable masks, formed mainly from polymers, often incorporate various chemical additives to enhance their performance. These additives, which include plasticizers, may be released during mask usage, presenting a novel source of human exposure to these compounds. In this study, the presence of 16 organophosphate esters (OPEs), 11 phthalates, and four alternative plasticizers, in four various types of face masks, were studied, as well as their release during simulated mask use (artificial laboratory conditions). Total plasticizer concentrations exhibited minimal variation across different mask types, with mean values of 7.27 µg/face mask for surgical, 8.61 µg/face mask for reusable, 11.0 µg/face mask for KN-95, and 13.9 µg/face mask for FFP2 masks. To explore plasticizer release behavior, inhalation experiments were conducted under different conditions. The findings revealed a significant temperature-dependent enhancement in plasticizer release from masks, subsequently increasing human inhalation exposure. The inhalation experiments showed variation in the release percentages, ranging from 0.1 to 95 %, depending on the specific compound and mask type. Notably, OPEs exhibited a mean release percentage of 1.0 %, similar to phthalates, which showed a 1.2 % release. Although alternative plasticizers were less frequently released, they still presented a notable percentage of release of 4.1 %. Daily intake estimations via inhalation ranged from 0.01 to 9.04 ng/kg body weight (bw)/day for these additives. Using these estimations, carcinogenic and non-carcinogenic risks associated with this exposure to these compounds were evaluated. All calculated values for the specific compounds studied in this paper remained below the established threshold limits. However, they do represent an additional exposure pathway that, when considered alongside other more predominant routes such as indoor/outdoor inhalation, dermal absorption, and dietary intake, makes the total exposure worthy of consideration.

This research work was funded by the European Commission NextGenerationEU (Regulation EU 2020/2094), through CSIC’s Global Health Platform (PTI Salud Global), by the Spanish Ministry of Science and Innovation (Project EXPOPLAS, PID2019-110576RB-I00), and Grant CEX2018-000794-S, funded by MCIN/AEI/10.13039/501100011033), and by the Generalitat de Catalunya (Consolidated Research Group 2021SGR01150). IDAEA-CSIC is a Centre of Excellence Severo Ochoa (Spanish Ministry of Science and Innovation, Project CEX2018-000794-S).

Peer reviewed