Emissions of p-dichlorobenzene and naphthalene from consumer products

Figures & data

Table 1. Conditions for p-dichlorobenzene experiments

Product	Environment	Volume (m^3)	AER (hr^−1)	Duration (Days)	Temprature (°C)	RH (%)	Air Speed (cm/sec)	Initial Surface Area (cm^2)
Closet air freshener	Chamber 1^a	10.8	40	21	22.2 ± 1.0	59.3 ± 5.1	3.1 ± 1.1	23.4 (slots)
								211 (cake)^b
	Closet 1	6.9	4.3	21	23.4 ± 1.7	46.8 ± 4.2	0.8 ± 0.9	23.4 (slots)
								210 (cake)^b
Container of moth crystals	Chamber 2^a	12.1	36	38.5	23.3 ± 0.4	39.8 ± 11.1	4.4 ± 2.1	42
	Closet 1	6.9	4.3	28	19.7 ± 3.4	49.8 ± 6.0	0.8 ± 0.9	42
Toilet bowl deodorizer	Chamber 2^a	12.1	36	15	22.1 ± 1.0	59.6 ± 5.1	3.1 ± 1.1	121
Notes: Mean values are shown along with ±1 standard deviation for each experiment, except for the closet experiments for which uncertainty (±) is based on error propagation analysis. ^aExperiments completed in triplicate. ^bCombined area of both cakes in casing.

Table 2. Conditions for naphthalene experiments

Product	Environment	Volume (m^3)	AER (hr^−1)	Duration (Days)	Temperature (°C)	RH (%)	Air Speed (cm/sec)	Initial Surface Area (cm^2)
Box of mothballs	Chamber 2	12.1	36	84	22.3 ± 0.6	65.3 ± 7.2	2.7 ± 1.8	50
	Closet 2	3.4	0.8	49	23.7 ± 2.6	44.3 ± 4.8	1.7 ± 1.2	50
Individual mothballs	Chamber 2^a	12.1	36	45.5	22.1 ± 0.8	67.9 ± 8.2	1.6 ± 1.4	3.3
	Garment bag	0.24	—	28	21.7 ± 0.1	43.3 ± 14.5	—	3.2
Notes: Mean values are shown along with ±1 standard deviation for each experiment, except for the box of mothballs for which uncertainty (±) is based on error propagation analysis. ^aExperiments completed in triplicate.

Figure 1. Mean emission rates for p-DCB. Bars around mean values correspond to ±1 standard deviation based on triplicate experiments, except for experiments in Closet 1 for which uncertainty (±) is based on error propagation analysis. Emission rates are plotted at the midpoints of measurement intervals.

Figure 2. Mean emission rates for naphthalene. Bars around mean values correspond to ±1 standard deviation based on triplicate experiments, except for the box of mothballs for which uncertainty (±) is based on error propagation analysis. Emission rates are plotted at the midpoints of measurement intervals.

Table 3. Experimental mass transfer coefficients

Product	n	Location	Mean k g (m/hr)
p-DCB
Closet air freshener	23	Chamber 1	1.3 ± 0.30
	7	Closet 1	1.2 ± 0.19
Container of moth crystals	39	Chamber 2	0.96 ± 0.22
Toilet bowl deodorizer	4	Closet 1	0.41 ± 0.10
	15	Chamber 2	4.0 ± 0.93
Naphthalene
Box of mothballs	12	Chamber 2	4.3 ± 2.0
	4	Closet 2	2.9 ± 0.77
Individual mothballs	21	Chamber 2	23 ± 7.5
	12	Garment bag	3.8 ± 3.0
Notes: n = total number of calculations of k g for a given product; k g = mass transfer coefficient shown here as mean of “n” with ±1 standard deviation.

Figure 3. Cumulative distribution plots for whole-house p-DCB and naphthalene emission rates based on homes in RIOPA Texas, California, and New Jersey.

Table 4. Gas-phase concentrations of pollutants in different locations while in use

Product	Location	Number of Samples, n	Gas Concentration, C g (μg/m^3)
p-DCB
Closet air freshener	Closet 1	4	28,000 ± 6500
	Bedroom 1	4	3200 ± 740
Container of moth crystals	Closet 1	4	3500 ± 2400
	Bedroom 1	4	430 ± 240
Naphthalene
Box of mothballs	Closet 2	4	1700 ± 570
	Bedroom 2	4	260 ± 120
Individual mothballs	Garment bag	1	13,700 ± 2470
	Chamber 3	4	200 ± 80
Notes: Mean values are shown along with ±1 standard deviation for each experiment, except for the concentration of naphthalene inside the garment bag (only one measurement was recorded) for which uncertainty (±) is based on error propagation analysis.