Ozone depleting substances (ODS) have become widely used
in our society, but we are not dependent on them. With the
exception of a few small applications that are considered
essential, such as the use of ozone-depleting substances in
Meter dose inhalers (MDIs) for delivering asthma
medication, there is a wide range of alternatives.
Refrigerants
Options for alternatives in refrigeration will depend on
the size and type of system. It will also depend on the
application as ozone depleting substances have been used as
both the refrigerant gases and the propellant in the
foam-blowing process. Replacements with lower ozone
depleting potentials - such as HCFCs - or no ozone
depleting potential - such as HFCs, hydrocarbons and
ammonia - are now available to reduce the potential impact
of new machinery on the ozone layer. In some cases, through
the use of alternative technologies, it might be possible
to minimise or even eliminate the use of refrigerants
altogether. Previously, measures for reducing the ozone
depleting impact of refrigeration included, where possible,
the recovery, recycling and destruction of the refrigerant
gas.
Foams
HCFCs were an important transitional substance in the
phase out of CFCs for foam blowing. Although still ozone
depleting, HCFCs have a much lower ozone depleting
potential that the CFCs previously used in this
application. However, with the advance of technology, the
transfer from HCFCs to completely non-ozone depleting
substances such as HFCs and pentane has almost been
finalised at the time of writing. EC Regulation 2037/2000
prohibits the use of HCFCs in the production of all foams
from 1 January 2004. Further information can be found in
the Department of Trade and Industry/Department for
Environment, Food and Rural Affairs (formerly DETR) booklet
'Guidance on the new EC Regulation No 2037/2000 on
substances that deplete the ozone layer'.
Solvents
The use of solvents containing CFCs,
1,1,1-trichloroethane, bromochloromethane and carbon
tetrachloride has been prohibited under EC Regulation
2037/2000. These substances were used in a variety of
applications such as in the cleaning of metal and
precision-engineered parts as well as in dry cleaning
processes. Dependency on solvents for cleaning applications
can be greatly reduced by minimising contamination in the
first place. Eliminating the need for the substances would
reduce the cost of meeting emission controls, cut recycling
costs and reduce waste disposal costs. Further information
can be found in the Department of Trade and
Industry/Department for Environment, Food and Rural Affairs
(formerly DETR) booklet 'Phase out of Ozone Depleting
Solvents'.
Fire fighting
Halon use in both fixed and portable systems became
widespread due to its exceptional fire extinguishing and
explosion suppression properties. Although halons represent
less than 2% by weight of the historic production of CFCs,
they are considered to be responsible for up to 25% of
ozone layer depletion. It is because of this that the EU
decided to incorporate a total decommissioning of all
non-critical halon systems into EC Regulation 2037/2000.
From December 2002, the sale and use of halons, including
recycled and reclaimed material was prohibited. Total
decommissioning of non-critical systems must be achieved by
31 December 2003. Water mist or detection-only devices can
replace many systems, however, as the severity and type of
hazards differ it is best to obtain the advice of a
technical expert before replacing any system. Further
information can be found in the Department of Trade and
Industry/Department for Environment, Food and Rural Affairs
(formerly DETR) booklet 'Phase out of Halons'.
Methyl Bromide
Methyl bromide which is both toxic and ozone depleting,
is a substance used in fumigation and soil sterilisation.
Although no direct replacement exists there are a number of
alternatives or potential alternatives available that can
be used, either alone or in combination, as the situation
requires.
Methyl bromide will be phased-out in developed
countries in 2005, although some critical use exemptions
may be agreed by UNEP. Further information can be found in
the Department of Trade and Industry/Department for
Environment, Food and Rural Affairs (formerly DETR) booklet
'Ban on Methyl Bromide'.
© Crown, The Ozone Layer, Defra (2003)