Last reviewed 8 December 2015
As their presence on the agenda at the ongoing climate talks in Paris demonstrates, ozone-depleting substances (ODS) are of great environmental concern. For the most part, use of these substances are banned, though there are certain laboratory uses which are exempt. In this feature article, Dr Lisa Bushby examines these uses, appraising the risks and utility of work involving ODS in laboratory settings, and looking over the process of registering uses with the European Union.
The ozone layer in the upper atmosphere protects humans and other organisms from solar ultraviolet (UV) radiation. In the 1970s, scientists found certain man-made chemicals could deplete the ozone layer, leading to an increased level of UV radiation at ground level. Overexposure to UV radiation gives rise to a number of serious health risks for humans, particularly sunburn, skin cancer and eye cataracts. There are also serious impacts for biodiversity; for example, increased UV radiation reduces the levels of plankton in the oceans and subsequently diminishes fish stocks. It can also affect plant growth, thus impacting agricultural productivity.
Most man-made ozone depleting substances are also very potent greenhouse gases. Eliminating such substances therefore also contributes to the prevention of climate change. Regulation (EC) No 1005/2009 on substances that deplete the ozone layer prohibits the use of ODS that are listed in Annex I to the Regulation. However, laboratory and analytical uses of Annex I ODS are exempted from this ban under certain conditions.
Defining analytical and laboratory uses
The use of ODS for laboratory or analytical purposes is only allowed if the use is essential. A use is considered essential only in those cases where there is no technically and economically feasible alternative or where the alternative is less acceptable from the standpoint of the environment and health.
An analytical use is defined as any use of ODS for the identification of compounds or the determination of the proportions of components in a mixture, for example the use of ODS as reference material.
Laboratory use means any use of ODS in a laboratory that is not an analytical use — for example, laboratory feedstock uses or uses of ODS in a toxicological study.
Laboratory feedstock use is the use of an ODS in a laboratory in a chemical synthetic procedure where the ODS is a reagent in a chemical transformation and is chemically converted from its original composition. This is different from cases where the ODS is used as a solvent or catalyst.
A use qualifies as laboratory feedstock use only if the product of the reaction is used in laboratories within the same company for research and development. The product or potential products from subsequent synthesis may not be given to third parties.
Laboratory ODS production is the synthesis of an ODS in a laboratory for the purpose of research and development as an intermediate or end product. Such production will only qualify as laboratory ODS production if:
the ODS is used in laboratories for research and development and the ODS is not made available to third persons (whether or not against payment), and
the ODS is not used for subsequent production of a product that is eventually placed on the market (whether or not against payment).
In any other case the production will be considered as production, as defined in Regulation (EC) No 1005/2009, and will be subject to the relevant provisions.
The following uses can usually be considered as essential laboratory or analytical uses, and are permitted provided that no non-ODS alternative is available.
The use of controlled substances as a reference or standard:
to calibrate equipment which uses controlled substances
to monitor emission levels of controlled substances
to determine residue levels of controlled substances in goods, plants and commodities.
The use of controlled substances in laboratory toxicological studies.
Laboratory uses in which the controlled substance is transformed in a chemical reaction (laboratory feedstock uses.
The use of methyl bromide inside a laboratory to compare the efficacy of methyl bromide and its alternatives.
The use of carbon tetrachloride as a solvent for bromination reactions involving Nbromosuccineimide (NBS).
The use of carbon tetrachloride as a chain transfer agent in free-radical polymerisation reactions.
Any other laboratory or analytical use for which a technically and economically feasible alternative is not available.
Types of ODS covered
Annex I substances are split into nine groups, as follows.
Groups I and II chlorofluorocarbons (CFCs) including trichlorofluoromethane and chlorotrifluoromethane.
Group III halons (eg bromotrifluoromethane).
Group IV carbon tetrachloride (CCl4).
Group V 1,1,1-trichloroethane.
Group VI methyl bromide (CH3Br).
Group VII hydrobromofluorocarbons.
Group VIII hydrochlorofluorocarbons (HCFCs).
Group IX bromochloromethane.
Any mixture, product or equipment that contains these substances or relies on them in order to function is covered by Regulation (EC) No 1005/2009.
The controlled substances placed on the market and made available for further distribution for laboratory and analytical uses are required to be manufactured to certain specified purities.
These high purity substances and mixtures containing controlled substances may be placed on the market only in re-closable containers or high pressure cylinders smaller than 3 litres or in ≤10ml glass ampoules. The containers must be clearly marked as substances that deplete the ozone layer and are restricted to laboratory use and analytical purposes. It should be specified that used or surplus substances should be collected and recycled, if practical, and the material should be destroyed if recycling is not practical.
Whether or not the use is essential has to be evaluated in the general risk analysis that has to be carried out before dangerous substances are used (eg under COSHH). All ODS are classified as dangerous substances under the chemicals legislation. They are not only dangerous for the environment, but some are also hazardous to human health. Since less dangerous alternatives are readily available for most uses, normally there is no need to use ODS.
The most popular ODS in laboratories are 1,1,1-trichloroethane, 1,2,2- Trichlorotrifluoroethane (CFC-113), carbon tetrachloride and methyl bromide. These substances are not only dangerous for the ozone layer but also give rise to other hazards. 1,1,1-trichlorethane is harmful. Carbon tetrachloride and methyl bromide are carcinogenic and mutagenic.
Registering the use of an ODS
Article 10(4) of 1005/2009 stipulates that any undertaking using ODS for laboratory or analytical uses must register using the European Commission’s labODS registry. This registration proves that the holder is registered and authorised to purchase or trade ODS for essential laboratory and analytical uses.
This requirement applies to any end user of ODS for essential laboratory or analytical uses such as laboratories of private companies, laboratories of public institutions, research centres or universities. It also applies to distributors of ODS based in the European Union making available (eg selling) ODS that were not produced or imported by themselves to other undertakings based in the EU.
To avoid any illegal placing on the market, ODS for essential laboratory or analytical uses should only be sold to customers within the EU market if the customer is able to demonstrate their registation. Distributors may be requested by their national competent authorities to demonstrate that sales took place only to registered customers. While not formally required, it has become common practice to request an end-user statement since this is already required for other kinds of controlled chemicals.