Proposal to add compounds to exclusion list of volatile organic compound definition: chapter 2

2.0 Background

VOC emissions contribute to the formation of air pollution. In the atmosphere, photochemical reactions between VOCs and other common airborne pollutants such as nitrogen oxides result in the formation of ground-level ozone, a respiratory irritant and a component of smog. Smog is a noxious mixture of air pollutants, consisting primarily of ground-level ozone and particulate matter that can often be seen as a haze in the air, especially over urban centres.

Air pollution has been shown to have a significant adverse impact on human health, with evidence showing an increased incidence of premature death, hospital admissions and emergency room visits. Studies indicate that air pollution is associated with increased risks of lung cancer and heart disease. Scientific evidence further indicates that ground-level ozone can have a detrimental impact on the environment. This impact can lead to reductions in agricultural crop and commercial forest yields, reduced growth and survivability of tree seedlings, and increased plant susceptibility to disease, pests and other environmental stresses (e.g. harsh weather).

On July 2, 2003, VOCs were added to the List of Toxic Substances in Schedule 1 of CEPA 19991. Some VOCs are excluded from the requirements of the List of Toxic Substance in Canada by way of an exclusion list. This exclusion list was similar to the United States Environmental Protection Agency’s (U.S. EPA’s) exclusion list at that time.

Since November 2004, the U.S. EPA has added the following thirteen compounds to the exclusions from their VOC definition in consideration of industry petitions. These compounds were determined to negligibly contribute to the formation of ground-level ozone:

  • 1,1,1,2,2,3,3-heptafluoro-3-methoxy-propane (HFE-7000)2
  • 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-(trifluoromethyl) hexane (HFE-7500)3
  • 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea)4
  • methyl formate (HCOOCH3)5
  • tertiary butyl acetate (TBAc)6
  • (1) 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-trifluoromethyl-pentane (HFE-7300)7
  • 1,3-dioxolan-2-one, 4-methyl- (propylene carbonate)8
  • dimethyl carbonate9
  • trans-1,3,3,3-tetrafluoropropene (HFO-1234ze)10
  • HCF2OCF2H (HFE-134) 11
  • HCF2OCF2OCF2H (HFE-236cal2)12
  • HCF2OCF2CF2OCF2H (HFE-338pcc13)13
  • HCF2OCF2OCF2CF2OCF2H (H-Galden 1040X and H-Galden ZT 130 (or 150 or 180))14

On October 17, 2011 and February 15, 2013, the U.S. EPA also proposed to add the following two compounds to the list of exclusions from their VOC definition:

  • 2,3,3,3-tetrafluoropropene (HFO-1234yf)15
  • trans 1-chloro-3,3,3-trifluoroprop-1-ene (SolsticeTM 1233zd(E))16

The U.S. EPA decision is still pending for these two compounds.

1 The VOC definition is under Item 65 of the List of Toxic Substances in Schedule 1


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