"THE DOSE MAKES THE POISON"
This chart looks at substances found in Environmental Tobacco Smoke (ETS)
for which measurements have actually been obtained – very few, of course,
because it is difficult to even find these chemicals in diffuse and diluted ETS.
It calculates the volume of a 100m3 sealed and unventilated enclosure
(about 20 by 20 feet with a 9- foot ceiling). Taking Environmental Protection
Agency (EPA) figures for ETS yields per cigarette, it determines the number of
cigarettes required to reach the lowest, most stringent published threshold for
For Benzo[a]pyrene, 222,000 cigarettes would be needed to reach the
lowest published "danger" threshold.
For Acetone, 118,000.
For Hydrazine, slightly more than 14,000.
Toluene would require 50,000 packs of smoldering cigarettes. At 20
cigarettes per pack, that's one million cigarettes.
Of course, the moment one introduces real world factors to the room –
a door, an open window or two, or a healthy level of mechanical air
exchange – achieving these levels becomes even more implausible.
Frankly, it is difficult to imagine a situation where these threshold
limits could be realized.
CALCULATED NUMBER OF CIGARETTES REQUIRED TO REACH A
THRESHOLD LIMIT FROM ETS IN A SEALED, UNVENTILATED 100m3 ENCLOSURE
AT STP (1)
|ETS Component||CAS Number||Molecular Weight||ETS Output (mg/cigarette)(2)||Threshold Limit (ppm)||Threshold Limit (mg/m3)||Cigarettes Required|
|2-Toluidine||(3 isomers) (3)||107.15||0.003||2||8.7||290,000|
|Formic acid||64-18-6||46.02||0.525||5 (8)||9.4||1,790|
|Polonium 210 (9)||210||0.4pCi||na||3pCi/liter (10)||750,000|
(TLV in ppm)(gram mol wt of substance)
(TLV in mg/m3)(24.45)
TLV in mg/m3 = ______________________________ TLV in ppm = ___________________
24.45 gram mol wt of substance
1. Limits expressed in ppm have been translated to mg/m3 for the
sake of clarity and volume calculation. New values have been incorporated,
and the lowest threshold (irrespective of source) has been used.
Unless otherwise noted, lowest threshold limit values were found in “1999
TLVs and BEIs,” American Conference of Governmental Industrial Hygienists.
2. Data from NTP RoC ETS, December 2-3, 1998, Table 1-1, pp 1-3, per EPA.
3. Three isomers o-Toluidine [95-53-4], m-Toluidine [108-44-1], p-Toluidine [106-49-0]. Mol wt for each is 107.15, TWA/TLV is 2 ppm for each.
4. OSHA, PEL-TWA has been raised to 200ppm, vacating a previous lower level of 180 mg/m3. I used the lower limit.
5. This calculation based on the lowest possible calculated OSHA/NIOSH threshold of 1 ppm.
6. Based on coal tar pitch volatiles [65996-93-2], as benzene solubles
7. OSHA PEL
8. NIOSH PEL-TWA, and HSDB
9. “Levels of polonium-210 in tobacco smoke are not believed to be great enough to significantly impact lung cancer” Hecht S, Tobacco smoke carcinogens and lung cancer. JNCI 1999;91:1194-1210.
10. EPA (1990c).