25/01/2005 - The Environment
Agency is today (Tuesday) calling on industry
to take a closer look at a chemical called
Tert-dodecanethiol (Tert-dodecylmercaptan,
TDM) to help clarify the possible risk to
the environment. This chemical is used in
products such as automotive parts, carpet
backing and some domestic appliances.
The call comes as the Environment Agency
presents its research to the UK Chemicals
Stakeholder Forum on the risk to the environment
of TDM. The resulting assessment indicates
that a number of uses of TDM (stemming from
emulsion polymerisation) pose a potential
risk to the UK environment.
The Environment Agency is looking to identify
and take action on chemicals of concern
to the environment and humans in implementing
its Chemical Strategy. The Environment Agency
is particularly concerned about those harmful
chemicals that have the potential to persist
in the environment and that can accumulate
in organisms including man. It is difficult
to determine safe levels for these substances.
Early identification and prompt action to
prevent them getting into the environment
is required. The Environment Agency has
provisionally identified TDM as one such
chemical.
The Environment Agency is asking the chemicals
industry to:
conduct further work to provide information
on both the intrinsic properties of the
thiols and the use pattern. In particular,
information is required on the levels of
residual TDM present in polymer emulsions
and final products;
further develop suitable analytical techniques
for analysis of TDM in rubber and polymer
emulsions and to determine the levels present;
provide information on the persistence of
this substance in the environment as soon
as possible, initially using a test to determine
its potential for oxidation in aqueous solution.
formulate measures to reduce the risks identified
in this report as a precautionary measure
working with the Environment Agency, Government
and UK Chemicals Stakeholder Forum.
Nick Cartwright, Chemicals Policy Manager
for the Environment Agency, said, "We
are calling on industry to clarify the risks
this substance may pose to the environment
and where appropriate to take action. There
are many data gaps and so we need more information
to create a clearer picture. It is hoped
the information that industry provides will
demonstrate that certain uses do not pose
a risk."
Where the Environment Agency currently
regulates any site using TDM under the IPPC
regulations the Agency will continue to
ensure that best available techniques are
used to minimise releases into the environment.
NOTES TO EDITORS:
A briefing note to industry is available.
The risk assessment report for TDM is also
available (see link).
There are currently no specific legislative
controls regulating the use of TDM in the
UK or EU. It is however on the list of chemicals
of concern for the UK Chemicals Stakeholder
Forum. The European Chemical Bureau with
the assistance of member states has drawn
up a list of substances that may meet PBT
criteria under the EU chemical strategy.
TDM is provisionally included on this list.
TDM is used as a reactive intermediate
in the production of styrene butadiene rubber
(SBR or E-SBR) and acrylonitrile butadiene,
or nitrile, rubber (NBR). This includes
use in automotive tyre treads, other automotive
applications such as mats and beading; footwear;
food contact materials including conveyor
belts and container seals; hoses; gaskets;
wires and cables and other rubber goods.
The other major use of TDM is in the production
of emulsion polymer dispersions. These are
used in the production of carpet backing
and underlay, textiles, paper coatings,
adhesives, dipped rubber goods, foam pillows
and mattresses and products for the construction
industry. Other uses of the dispersions
include the manufacture of acrylonitrile
butadiene styrene - (ABS) plastics used
for applications such as automotive parts,
domestic appliances (vacuum cleaners, fridges,
hairdryers) and toys. TDM is also used in
the production of certain types of polystyrene.
TDM is produced at three sites in the EU,
located in France, Germany and Belgium.
There is no UK production.
As required under the Integrated Pollution
Prevention and Control (IPPC) regulations
the Agency regulates a number of processes
and some of these processes may use TDM
(or polymer dispersions containing low levels
of residual TDM) in their operations.
New substances brought onto the market
have to undergo thorough risk assessments
to ensure they pose no unacceptable risks
to human health or the environment. Many
older substances have not been through this
risk assessment process as they were brought
on to the market before risk assessment
legislation existed. The Environment Agency
launched its own Chemicals strategy in October
2003 - this includes identifying substances
where investigation or risk assessment is
needed and proactively working with the
government so that early action can be taken
on such substances.
