Table 1.

Summary of the two studies where urine samples were collected before and after live-fire training and subsequently analyzed for VOC metabolites

	Residential fire study	Training fire study
Design	Repeated measures	Repeated measures
Fire structure and fuels	Fires ignited in two rooms of a 111 m2 wood frame residential structure containing residential furnishings, including double bed with polyurethane foam topper, stuffed chair, wood side table and dresser, lamp, flat screen TV, and polyester carpet with recycled polyurethane foam padding oriented as in a residential bedroom common in the 21st century United States.	Training fires involved obscuring visibility by 1) Burning of pallet and straw in a ground-based rack inside single story concrete training building, 2) Burning of oriented strand board (OSB) attached to the training structure ceiling, along with pallet and straw in a ground-based rack in each of two rooms of a T-shaped metal shipping container. Two types of OSB were used denoted as Alpha and Bravo (see supplemental files for more details), 3) Generation of simulated smoke and electronic flame inside series of metal shipping containers.
Participants	12 firefighters per response team, 3 response teams, each team fought 4 fires (1 per day), firefighters assigned to new positions after two fires. Positions included: attack (2), search (2), outside vent (2), overhaul (4), incident command and pump operator (2). There were 41 total participants as five firefighters did not complete all 4 fires and were replaced.	24 firefighter students total. Six crews of 4 firefighter students. Each crew fought 1 training fire per day over 3 non-consecutive days. 10 instructors total (two groups of 5 instructors) who oversaw 3 training fires per day over 3 non-consecutive days.
Sampling	Spot urine collected pre-fire and 3-hr post fire.	For the firefighter students, spot urine collected pre-fire and 3-hr post fire. For the instructors, spot urine collected pre-fire and 3-hr post third fire (end of shift).
Total number of samples	Only urine samples collected from firefighters assigned to interior firefighting (“Attack” and “Search”) were analyzed for VOC metabolites. 24 pre and 24 3-hr post fire urine samples were analyzed from both the attack and search firefighters.	Only urine samples collected during OSB and pallet and straw scenarios were analyzed for VOC metabolites. For students, 36 pre and 36 3-hr post fire urine samples were analyzed. For instructors,12 pre and 12 end-of-shift urine samples were analyzed.