Human toxicity: kg 1,4 dichlorobenzene (1,4-DB) eq. *
The emission of some substances (such as heavy metals) can have impacts on human health. Assessments of toxicity are based on tolerable concentrations in air, water, air quality guidelines, tolerable daily intake and acceptable daily intake for human toxicity. Impacts to air and water have been combined in the ratings tables. Characterisation factors, expressed as Human Toxicity Potentials (HTP), are calculated using USES-LCA, as with Ecotoxicity, which describes fate, exposure and effects of toxic substances for an infinite time horizon. For each toxic substance HTPs are expressed using the reference unit, kg 1,4-dichlorobenzene (1,4-DB) equivalent.
Indoor air quality and its effect on human health is not covered by this category.
Toxicity*: It should be noted that issues relating to toxicity generate much debate. Designers are advised to carefully review the material supplier’s guidance, to note any relevant regulations, codes and standards appropriate to different industries and materials and to consider the context and application within which the materials are to be used. The results in the Green Guide do consider some toxic effects, but these should in no way be considered comprehensive for any of the material alternatives considered. Many of the chemicals used in society have not undergone a risk assessment and assessment techniques are still developing.
See also the following study relating to human toxicity assessment for polycyclic aromatic hydrocarbons (PAHs):
Improving human toxicity assessment for polycyclic aromatic hydrocarbons (PAHs)
from primary aluminium production, by D. Li, O. Jolliet & M. Huijbregts