What are VOCs?
The abbreviation VOC (Volatile
Organic Compounds) refers to the group of volatile organic compounds. VOC describes gas- and vaporous substances of organic
origin in the air.These
include, for example, hydrocarbons,
alcohols, aldehydes and organic acids.
Many solvents, liquid fuels and synthetic materials can occur as VOC, as well as numerous organic
compounds that are formed in biological processes. Hundreds
of different individual
compounds can occur
together in the air. What are the sources
of VOC?
VOCsarise from very different
sources. Biological
processes can be outside
air sources, for
example, plant material exchange, putrefaction and decomposition processes. Other external
air sources are industrial
processes where materials
from incomplete combustion occur (especially road
transport emissions),or even as volatile
by-products from industrial and commercial operations.
Potential indoor
sources are products and materials for construction of buildings and furnishing (for
example, floor, wall and
ceiling materials, paints,
varnishes, adhesives, furnishings
and decorative materials).
Also
significant are care,
cleaning and hobby products, including tobacco smoke, even food
preparationand
human metabolism.
Compared to outdoor air,indoor sources in Central
Europe generally have a significantly greater health
significance because people spend most time in buildings.
In addition, the distance to the VOC sources indoors is usually low. VOC from the outside air can also enter into
the interior. Usually,
however, the original interior concentrations are
reduced during airing. How
are VOCsin the air?
If solvent
or liquid fuels evaporate,
andliquid
or pasteproducts dry,VOCsescape in large quantities into the surrounding air. Less
obvious is the proliferation
of different impurities that
are not firmly embedded in products. It can slowly release from the surface
of the product to the air,and be constantly replenished from the productunder
the surface (Material Emission).
This applies
to, for example, residual solvent and components in plastics (monomers),
additives such as plasticizers,
solubilizing agents, antioxidants, stabilizers and catalysts from the production process, as
well as accompanying substances such
as fragrances, flame retardants and biocide agents.
Typical VOCs are also terpenes.
They are made from materials and products of natural origin that are released
intothe air, for example items made of
wood. VOCs are also formed as reaction
products, for example, between oxygen, ozone or water with ingredients of
natural origin, such as those
contained in wood and vegetable oils. What
health effects can VOCs
have?
Usually, the individual VOC concentrations
are very low,and health problems are not
to be feared. Concentrations that cause health effects can occur immediately after construction and extensive
renovation work, and in
the case
of improper handling andextensive
useof
unsuitable products. Odors, irritation and symptoms
that can not be directly
associated with a disease, have been
described as acute effects on humans. These
effects must be avoided,as researchers have derived from toxicological assessments that there are possible chronic effectsparticularly
natural carcinogenic, mutagenic and toxic effects for
reproduction. If
such effects of substances are known, these may no longer be used
as a rule in final products(i.e. the banning
of certain chemicals). Not completely ruled out, however,
is that VOCs with such potential
impactare
included in traces in the product, if they were present in uncontrolled primary products or recycled
materials. How can VOCsbe reduced?
Consumers should
choose low-emission products and materials. They
can be based on eco-labels such as the Blue Angel
(Germany). For
larger construction or renovation measures,one
can see if the materials
are tested according to
the AgBB evaluation scheme. Both materials with a recognized eco-label,as well as successful testingaccording to the AgBB scheme,offer a guarantee that the
possible VOC tax is reduced to a low level.
If health
problems occur in the household and a connection with VOC is
suspected, the search for the sources is usually difficult.
Indoor air
measurements and emission measurements on different
materials are very expensive and often do not achieve the
desired clarity. Residents
should therefore seek professional advice. You
will find expertsin
local health and environmental
agencies, the chambers
of commerce or the
Internet. Professionals can often determine
the probable VOC sourceby an inspection of the apartment and
by interviewing residents. Oncethe sources of VOC pollution are clearly
identified, it must be decided individually on their disposal - depending
on the nature and extent of
the possible health detriment, according to the amount and
expected reduction in VOC
concentration and the cost. Alsoexpert advice should be
included, on
whether and how the VOC sources
are to be removed, trappedor treated. Basically,
it is always helpful to reduce VOC concentration indoorsby airing. |
[zoom]