Protection of the Ozone Layer

The stratospheric ozone layer protects life on Earth from the harmful effects of the sun's radiation. It is being damaged by emissions to the atmosphere of chlorofluorocarbons (CFCs) and a number of other man-made chemicals. In order to protect the ozone layer these substances need to be phased out as soon as practically possible.

This phase-out is continuing to gather momentum. Through the Montreal Protocol on Substances that Deplete the Ozone Layer a number of solvents, extensively used in chemical analysis are now effectively no longer available in the purity required for their intended use.

• Carbon Tetrachloride
• 1,1,2-Trichlorotrifluoroethane (Freon, CFC113)
• 1,1,1-Trichloroethane (Methyl Chloroform)

Over 170 countries have now ratified the Montreal Protocol. Within the EU, the protocol was previously enforced by EC Regulation 3093/94. However, recent changes to the Montreal Protocol have made it necessary to introduce tighter restrictions resulting in a new EC Regulation No 2037/2000 on ozone depleting substances, applicable from 1st October 2000. From this date a ban has been introduced on the use of CFCs, 1,1,1-Trichloroethane and Carbon Tetrachloride for any solvent application.

With the original introduction of the Montreal Protocol, it had been recognised by the authorities that a wholesale ban of such materials from the laboratory could impede work of a worthwhile nature (such as monitoring of pollutants in water). An exemption was therefore granted for essential laboratory uses, including research and development. However, in practice this has meant that the banning of manufacture and the requirement to recycle solvent resulted in less and less pure material becoming available on the market. Furthermore, what was available became so expensive that laboratory users were forced to seek alternatives, not through altruistic reasons, but simply because of availability and economics.

The laboratory use exemption continues beyond 1st October 2000. But effectively the only practical use of these solvents in the laboratory is now in very small volumes as reference materials in environmental monitoring studies.

So, what are the alternatives? At ROMIL, we suggest our Tetrachloroethylene SpS (ROMIL Code H702) as an alternative for infra-red applications. This may be used as a direct replacement for 1,1,2-Trichlorotrifluoroethane (Freon, CFC113) in the analysis of hydrocarbons in aqueous media. It is both safer to use and has similar physical properties. Suitable for both gravimetric and IR methods and is essentially transparent in the IR region 3200 to 2700 cm-1. Carbon Tetrachloride may be similarly substituted.

In the petrochemical industry, Chloroform has been found to be an acceptable alternative in some analyses. We suggest our Chloroform SpS stabilised with amylene (ROMIL Code H140) as this stabiliser gives less absorption in the C-H region than does the normal ethanol stabiliser.

An Oil-In-Water Monitoring Club has been formed to act as a central contact point for all the information on the subject that up to now has not been readily available, with the aim of eliminating the duplication of work by different offshore operators. This has been a particular problem as new information and developments appear constantly. Oil-In-Water monitoring and analysis is a subject of considerable interest to both regulatory authorities and industry. Accurate and reliable measurement of Oil-In-Water plays an significant role in the minimisation of oil pollution entering the environment. Click here to access the Club's web site.