Strauch 2016.

Study characteristics
Methods	Simulation study, cross‐over RCT How was the simulation performed? 2 different simulations of contamination of the Filtering Facepiece Respirator (FFR) were performed: 1 in which the FFR was contaminated but not the hands and another one in which the hands were contaminated but not the FFR 1. Contamination of the FFR and clean hands: 20 participants performed 3 trials of FFR with removal tabs (tab+) and tab‐ masks each in random order 2. Clean FFR and contamination of hands: 20 participants performed 1 tab+ trial and 1 tab‐ trial How was the exposure simulated? To contaminate the FFR, 7 mL of fluorescent tracer was brushed onto the entire outer surface of the test FFRs. As only the outer surface of the FFR was contaminated with the fluorescent tracer, transfer from the FFR to the hands would only occur if the FFR was doffed improperly by grasping the contaminated surface. 2. For the hand contamination test, 1 mL of fluorescent tracer was applied and rubbed into the hands of the test participant before removal of a clean FFR with or without tabs. The fluorescent tracer was prepared by suspending 1 g of GloGerm (GloGerm Company; Moab,UT) powder suspended in 25 mL of mineral oil.
Participants	N = 20 aged 18‐60 HCW Volunteers employed as HCW, that were enrolled in a respiratory protection programme and experienced in wearing FFRs were preferred, but a potential participant was not excluded if all of the qualities were not met. Volunteers were excluded if they had a history of skin cancer, sensitivity to UV light, or burns from a black light Country: USA
Interventions	Intervention: modified PPE: masks with tabs Mask with tabs; N‐95 mask with 4 red foam tabs attached to straps to assist in mask removal Control: mask with out tabs
Outcomes	Contamination of the hands resulting from exposure to a contaminated mask Contamination of the head resulting from exposure to contaminated hands: the participant’s head, face and hair were photographed under UVA light for contamination with fluorescent tracer.
Notes	Location: USA; funding source and conflict of interest were not published; reported on Lumens as a measure of contaminate but the written results did not match those presented in figure.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "each subject doffed one randomly assigned FFR" Unclear how randomisation was performed
Allocation concealment (selection bias)	Unclear risk	Unclear if allocation was irrevocable
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Not reported but unlikely to have influenced the outcome that was assessed by observers
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear if there were missing data
Selective reporting (reporting bias)	Unclear risk	No protocol available
Other bias	Low risk	No other biases detected