Page 106 - Materials Chemistry, Second Edition

L1644_C03.fm Page 81 Tuesday, October 21, 2003 3:11 PM

TABLE 3.3
Characterization Values for Ozone Layer Depletion

Ozone layer depletion
Medium Chemical Substance u Value
Air 1,1,1-trichloroethane kg 1.20 × 10 1
Air CFC (hard) kg 1.00
Air CFC (soft) kg 5.50 × 10 -2
Air CFC-11 kg 1.00
Air CFC-113 kg 1.07
Air CFC-114 kg 8.00 × 10 -1
Air CFC-115 kg 5.00 × 10 -1
Air CFC-12 kg 1.00
Air CFC-13 kg 1.00
Air Halon-1201 kg 1.40
Air Halon-1202 kg 1.25
Air Halon-1211 kg 4.00
Air Halon-1301 kg 1.60 × 10 1
Air Halon-2311 kg 1.40 × 10 -1
Air Halon-2401 kg 2.50 × 10 -1
Air Halon-2402 kg 7.00
Air HCFC-123 kg 2.00 × 10 –2
Air HCFC-124 kg 2.20 × 10 –2
Air HCFC-141b kg 1.10 × 10 –1
Air HCFC-142b kg 6.50 × 10 –2
Air HCFC-22 kg 5.50 × 10 –2
Air HCFC-225ca kg 2.50 × 10 –2
Air HCFC-225cb kg 3.30 × 10 –2
Air Methyl bromide kg 6.00 × 10 –1
Air Tetrachloromethane kg 1.08
Source: Goedkoop (1995).

internationally accepted equivalency factors for toxic compounds express the sub-
stances’ “impact potentials.” For the calculation of equivalency factors, consider-
ations about fate and transport, exposure assessment and human toxicity have been
considered.
A frequently used indicator for evaluating human health effects of a functional
unit is human toxicity potential (HTP) (Hertwich et al., 2001; Guinée et al., 1996).
HTP is a site-generic impact potential that is easy to apply; however, it has a limited
environmental relevance because it is based on a multimedia environmental fate
model that assumes uniformly mixed environmental compartments. In other words,
it represents the behavior of chemicals in a uniform world model environment.
Two HTP methods developed by the Center of Environmental Sciences at Leiden
University (CML) (Heijungs et al., 1992) and within the Danish Environmental

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