Threat by chemical substances: Legislation, production, use and waste - Environmental Deterioration and Contamination: Problems and their Management - page 49

◦ Good laboratory practice: inspection and verification of laboratory studies on

all chemicals (GLP, verification, 2004);

◦ Exposure to chemical agents (Exposure to chemicals, 1998);

- Management of pollutants and waste:

◦

Convention on long-range transboundary air pollution (Air pollution, 1981);

◦ Elimination and minimization of production, use and release of persistent

organic pollutants (POPs) (Stockholm Convention, 2006);

◦ Controlled management of hazardous waste -until the end of 2010 (Haz-

ardous waste, 1991);

◦ Basel Convention (Basel, 1997);

◦ Community strategy for dioxins, furans and polychlorinated biphenyls (PCB,

2001);

◦

Disposal of PCBs and polychlorinated terphenyls (PCB, PCT, 1996).

5 WHICH ARE THE MOST DANGEROUS CHEMICAL
SUBSTANCES?

Some chemicals were identified to be dangerous a long time ago, but there are many
others of emerging concern, discovered in the recent past, once the analytical methods
were able to detect them at very low concentrations. Risks to human health and the
environmental associated with the presence, frequency of occurrence, or source of
these contaminants might be not fully known.
The list of known hazardous environmental chemicals is long. The environmen-
tally (i.e. via the environment) hazardous chemicals are generally not classified simply
according to their chemical properties and type of chemical species, as in chemistry.
Priority is given to the characteristics responsible for their environmental risk, thus
chemical substances are classified according to their
- Environmental fate properties and effects;

- Function and use;

- Applied technologies for production and use;

- Quantities produced and used, as well as the amount of waste containing the

substance;

- Chemical structure and species.

The environmental fate and adverse effects are certainly not independent of the
chemical structure, but by referring to chemical mutagens or reprotoxic chemicals we
equally mean metals and their inorganic and organic compounds, chlorinated hydro-
carbons, polycyclic aromatic compounds, etc., i.e., chemically very different substances
enrolled in the same group while the hazardous effect has priority when classifying
them. In this topic, we often give priority to the hazardous effects and the closely
related environmental transport and fate properties of chemicals. But we usually per-
form a mixed classification, according to the utilization and handling of the substance,
e.g., biocides, pesticides, surfactants and combustion wastes. Legislation and practice
distinguish dangerous products according to their production volume (mass), giving
special attention to HPV chemicals. Some groups refer to the origin of the chemical