Table 3.

Studies investigating the presence of chemicals in PPE leachates.

Type of mask	Sample collection	Experimental set up	Chemicals identified from leachates	Methodology	Instrument used	Levels	Reference
Surgical masks, Self-filtering masks – KN95, Self-filtering masks - FFP2, Self-filtering masks - FFP3, Filters for homemade masks, Reusable masks; 20 samples	Manufacturers in China, Spain and Germany	1.Airborne particulate matter in 2 paper-mache dummy heads was collected using a Personal Environmental Monitor with a flow rate of 10 L/min. 2.Each mask was tested for 6 h, for both indoor and outdoor.	Triethyl phosphate, triphenylphosphine oxide, tris(2-chloroisopropyl) phosphate, Tri-n-butyl phosphate, tris(1,3- dichloro-2-propyl) phosphate, triphenyl phosphate, diphenylcresyl phosphate, 2-isopropylphenyl diphenyl phosphate, tricresyl phosphate, bis(4- isopropylphenyl)phenyl phosphate, tris(2- isopropylphenyl) phosphate and tris(2-ethylhexyl) phosphate	1.Filters were cut and added with 25 ng of an internal standard mixture. 2.Hexane:acetone (1:1) were added to filters and sonicated. 3.Solvent was concentrated & redissolved with methanol to 500 µL	Thermo Scientific TurboFlow™ system consisting of a triple quadrupole (QQQ) MS	16.3 – 27,735 ng/mask	Fernández-Arribas et al. (2021)
Thirty-six different brands of single-use face masks, including six medical masks and 30 nonmedical masks	Local stores in Toronto, Canada, in 2021	–	Synthetic phenolic antioxidants: butyl-4-methylphenol, 2,4-di-tert-butyl-phenol, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)methyl]− 1,3,5-triazinane-2,4,6-tri-one Organophosphite antioxidants: tris(2,4-di-tert-butylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) Phosphate, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphate, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite	~0.04 g of sample was into small pieces after which three internal standards were added. -The sample was then extracted with 4 mL of methanol. -After centrifugation, 1 mL of the extract was transferred into an injection vial.	Liquid chromatograph coupled to a triple-quadrupole mass spectrometer	Synthetic phenolic antioxidants: 4.44 × 103 to 9.15 × 104 ng/g Organophosphite antioxidants: 1.55 × 104 to − 5.13 × 105 ng/g	Liu and Mabury (2021)
Disposable Face masks	Manufacturers in China	–	Metals: Cu, Cd, Co, Pb, Sb and Ti Caprolactam (PA 66 monomer) PEG derivatives (prevalent in all masks) PA6 trimer PA66 trimer or PA6 tetramer Aromatic pyrrole like compound Olumucine like compound N-Undecyl-1-undecanamine C21H47N2O8 C22H52O5N6Na	1.10 face masks for each batch submerged in 1.5 L deionized water for 4 h and agitated. 2.Leachate was then filtered through 0.1 µm Al2O3 filter. 3.Filters dried for 2 h at 50 °C. 4.Metal analysis: leachate was acidified with 1 mL 1 M HNO3 acid. 5.For polar organic compounds leachate was directly injected into liquid chromatography.	Scanning Electron Microscope, Fourier-transform infrared spectroscopy, -Inductively coupled plasma mass spectrometry, -Liquid Chromatography and Mass-spectrometry	Metals (microgram L-1) Cd: 0.01 – 1.91 Co: 0.54 – 0.59 Cu: 0.85 – 4.17 Pb: 0.01 – 6.79 Sb: 1.06 – 393 Ti: 0.06 – 0.64	Sullivan et al. (2021)
Wet wipes	Families residing in the city of Guangzhou, South China	1.Hand wipes from a total of 45 adults and 30 children 2.Gauze pads soaked with isopropyl alcohol and used to wipe the entire surface of both hands. 3.Prior to sampling participants were told not to wash hands for at least 2 h & to fill out a questionnaire about their demographic and dwelling characteristics.	60 Plastic additives (PAs): Phthalates, Mono-phthalates, Non-phthalate plasticizers, UV stabilizers: benzotriazoles, benzothiazoles, benzophenones, Antioxidants, Organophosphate esters, and Bisphenols	1.Wipes were spiked with surrogate standards and extracted with 10 mL of methanol/water, 6 mL of acetonitrile, 6 mL of ACN/isopropanol, and 6 mL of hexane/isopropanol. 2.Target analytes were eluted out with 5 mL of ACN and 5 mL of methanol and concentrated.	1.Shimadzu HPLC coupled to AB Sciex 5500 Q Trap MS/MS 2.Agilent 7890B gas chromatography coupled to a 5977 A mass analyzer	ΣPAs: Adults: 650–87,030 ng Children: 1230 −19,360 ng	Chen et al. (2021b)