technical guidance documents - Institute for Health and Consumer ...

ENVIRONMENTAL EXPOSURE ASSESSMENT
Besides releases from point sources, diffuse emissions from articles during their service life may
contribute to the total exposure for a substance. For substances used in long-life materials this
may be a major source of emissions (both during use and as waste remaining in the environment,
see Section 2.3.3.5).
Emissions related to the waste life stage can take place several decades after production and
processing of a substance. They may follow the market volume of the substance with a delay
specific for a certain type of product. Emission patterns (e.g. route, quantity and trend in time)
may also be determined by the type of treatment in relation to substance properties. Little is
known of the magnitude of long-term releases, e.g. of metals or of organic substances that do not
degrade anaerobically (see Section 2.3.3.6).
2.3.3.3 Release estimation
It is clear that the releases of a substance are dependent on the use patterns. Three categories are
distinguished, i.e. main category, industry category and function or use category. An overview of
these categories can be found in Chapter 5. The main categories are intended to describe
generally the exposure relevance of the use(s) of a substance. In the context of environmental
risk assessment they are also used to characterise release scenarios for the estimation of
emissions to the environment during specific stages of the life-cycle of the substance
(production, formulation, and industrial/professional use). They can therefore be allocated to
release fractions, which are used as default values where specific information is missing. The
following Main Categories are distinguished:
• use in closed systems: refers to the industrial/professional use stage when a substance is used for
example in a transformer or a circulation circuit of a refrigerator, or it may refer to the stage of
production where a substance like an intermediate is manufactured in closed apparatus;
• use resulting in inclusion into or onto a matrix: refers to the stage of formulation, e.g. when
a substance is included in the emulsion layer of a photographic film. It also may refer to the
stage of industrial/professional use, e.g. when a substance, applied as a uv-stabiliser in paint,
ends up in the finished coating layer;
• non-dispersive use: relates to the number (and size) of the emission sources;
• wide dispersive use: relates also to the number (and size) of the emission sources.
The industry categories specify the branch of industry (including personal and domestic use, and
use in the public domain) where considerable emissions occur by application of the substance as
such, or by the application and use of preparations and products containing the substance. Some
important emission sources have not been included specifically in this scheme and hence have to
be allocated to category “Others” (no. 15/0), e.g. emissions of substances (in preparations) other
than fuels and fuel additives used in motor vehicles.
The use or function category specifies the specific function of the substance. There are 55
categories which have a varying level of detail. For substances used in photography for example,
there is only one category: 42 “Photochemicals”. Depending on the specific function of the
photochemical, however, emissions can vary to a great extent, e.g. substances used to influence
the crystal growth of silver compounds at the production of films are released by over 50%,
while other substances at this stage will hardly be released. There is no general category as
“Plastics additives” and many other specific categories lack as well; exceptions are categories
like 47 “Softeners” (= plasticisers) and 49 “Stabilisers” (heat and UV-stabilisers).
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