Table 1. Emission rates of known THS compounds in online PTR-TOF MS data.

All compounds reported here have been previously observed in tobacco smoke (6, 21, 22). For the isomer distributions for C₈ aromatics, C₉ aromatics, and C₁₀ aromatics, consult Fig. 2D.

Compounds		Average emission rate during THS events (mg/hour)	Emission rate regression to 2,5-dimethylfuran		Emission rate regression to benzene		t test: R-rated versus G-rated emission rates
		Mean ± SD*	r	Slope	r	Slope	t	P value†
Aromatics	Benzene‡§	3.46 ± 1.79	0.87	4.73 ± 0.73	1.00	1.00 ± 0.00	4.14	0.001
	Toluene‡§	5.91 ± 2.78	0.74	6.14 ± 1.53	0.93	1.42 ± 0.15	2.79	0.009
	C8 aromatics‡§	4.84 ± 2.11	0.74	5.00 ± 1.26	0.92	1.15 ± 0.14	2.81	0.010
	C9 aromatics‡	3.12 ± 1.37	0.72	3.28 ± 0.88	0.91	0.77 ± 0.10	4.36	<0.001
	C10 aromatics‡	0.91 ± 0.42	0.75	1.03 ± 0.25	0.91	0.23 ± 0.03	4.62	<0.001
	Phenol‡§	0.57 ± 0.32	0.85	0.74 ± 0.13	0.77	0.13 ± 0.03	2.60	0.011
	Styrene‡§	0.71 ± 0.35	0.72	0.84 ± 0.22	0.83	0.18 ± 0.03	5.07	<0.001
	Benzaldehyde‡	0.24 ± 0.10	0.59	0.18 ± 0.07	0.57	0.03 ± 0.01	2.98	0.006
	Cresols‡§	0.26 ± 0.14	0.87	0.34 ± 0.05	0.81	0.06 ± 0.01	2.93	0.006
	Naphthalene‡§	0.34 ± 0.16	0.88	0.40 ± 0.06	0.88	0.07 ± 0.01	2.78	0.008
Furanoids	Furan	0.43 ± 0.40	0.90	0.90 ± 0.12	0.74	0.14 ± 0.03	1.83	0.045
	2-Methylfuran	0.83 ± 0.75	0.98	1.92 ± 0.11	0.85	0.31 ± 0.05	3.15	0.006
	2,5-Dimethylfuran§	0.48 ± 0.36	1.00	1.00 ± 0.00	0.87	0.16 ± 0.02	3.76	0.002
	Furfural‡	0.60 ± 0.36	0.90	0.86 ± 0.11	0.80	0.14 ± 0.03	2.29	0.020
	Furfuryl alcohol‡	0.31 ± 0.14	0.93	0.37 ± 0.04	0.83	0.06 ± 0.01	3.37	0.003
Carbonyls	Formaldehyde§	0.94 ± 0.50	0.87	1.25 ± 0.20	0.83	0.22 ± 0.04	3.84	0.001
	Acetaldehyde§	9.07 ± 6.51	0.90	15.44 ± 2.20	0.84	2.64 ± 0.50	2.86	0.009
	Acrolein§	0.73 ± 0.57	0.94	1.43 ± 0.14	0.87	0.24 ± 0.04	3.31	0.004
	Acetone∥	20.45 ± 10.45	0.69	19.54 ± 6.43	0.72	3.75 ± 1.14	3.06	0.010
	Methacrolein	0.61 ± 0.43	0.93	1.10 ± 0.12	0.85	0.18 ± 0.03	3.14	0.004
	2,3-Butanedione	1.00 ± 0.68	0.90	1.68 ± 0.23	0.72	0.25 ± 0.07	3.59	0.003
Other	Acetonitrile§	1.20 ± 0.86	0.96	2.24 ± 0.19	0.80	0.35 ± 0.07	3.27	0.004
	Acetic acid∥	8.40 ± 2.21	0.68	5.84 ± 1.99	0.69	1.09 ± 0.36	3.10	0.010
	Isoprene	4.55 ± 2.89	0.84	6.81 ± 1.22	0.77	1.15 ± 0.26	2.93	0.006
	Monoterpenes‡∥	2.14 ± 1.91	0.58	2.62 ± 1.05	0.46	0.41 ± 0.23	0.99	0.179

*Emission rates were calculated from the THS emission events of 10 R-rated movie showings unless noted otherwise. High SDs indicate high movie-to-movie variability. Emission rates include isomers and ionization products not mentioned above (e.g., methyl vinyl ketone with methacrolein).

†P values in bold represent those that are statistically significant (P < 0.05) for the unpaired two-sample t test, evaluating whether the emission rates were higher in the 10 R-rated movie screenings than the five family movies. See section S1 for more details.

‡Compounds were identified with an offline GC-MS method for ≥C₆ compounds using standards and the National Institute of Standards and Technology library.

§Hazardous air pollutants (HAPs) as assigned by the EPA or in the case of 2,5-dimethylfuran, showed cytotoxicity in previous studies (1).

∥Emission factors use data from days 1 to 3 for acetone and acetic acid because large non-THS related emissions from cleaning were observed before the start of day 4 for these compounds, which biased calculations. The monoterpenes values exclude the third film on day 1 because of a large non-THS spike after the start of the film.