Table 4.

BZCs (μg m⁻³) of monomeric and polymeric HDI^a by type of paint booth

Analyte	Booth type	nb	Nc	Non-detectsd	Summary statistics			REML estimates (logged data)
					GM	GSD	Range	Within-worker variance	Between-worker variance
HDI	Downdraft	31	197	26	2.72	5.74	0.003–48.0	2.23	0.67
	Semi-downdraft	10	60	1	10.1	2.11	0.50–65.5	0.48	0.12
	Crossdraft	10	31	1	9.65	5.58	0.0007–179	0.61	5.18
	All booths	47	288	28	4.10	5.42	0.0007–179	1.78	0.71
Uretidone	Downdraft	31	197	146	1.27	20.7	0.0004–1430	4.60	1.61
	Semi-downdraft	10	60	18	6.96	10.7	0.02–613	0.98	6.92
	Crossdraft	10	31	13	5.39	21.2	0.0007–521	2.89	10.2
	All booths	47	288	177	2.12	20.3	0.0004–1430	3.79	2.90
Biuret	Downdraft	31	197	115	3.46	9.68	0.003–798	3.20	1.70
	Semi-downdraft	10	60	10	44.7	8.23	0.03–734	1.15	4.45
	Crossdraft	10	31	5	49.4	17.1	0.004–7720	2.20	11.0
	All booths	47	288	130	7.85	13.3	0.003–7720	2.78	2.95
Isocyanurate	Downdraft	31	197	2	1210	4.94	0.09–17800	1.98	0.59
	Semi-downdraft	10	60	0	2160	2.08	269–8920	0.29	0.37
	Crossdraft	10	31	1	1600	7.98	0.46–18700	0.64	7.52
	All booths	47	288	3	1410	4.65	0.09–18700	1.66	0.83

GSD, geometric standard deviation; REML, restricted maximum likelihood.

^aMultiple imputation (n = 10 imputed datasets) was used to impute air-sampling data below detection limits.

^bNumber of workers. A total of four painters painted in more than one booth type; two painted in both crossdraft and semi-downdraft booths, one painted in both crossdraft and downdraft booths, and one painted in both semi-downdraft and downdraft booths.

^cNumber of samples. Represents the TWA recorded for each paint task. Of the 296 measurements, eight were excluded due to sampling pump malfunction.

^dNumber of samples collecting non-detectable levels.