Proposed restriction of diisocyanates. Source: Gina Sanders – Fotolia

By Kerstin Heitmann, UMCO

Many diisocyanates are classified as skin and respiratory sensitisers and are thought to be the trigger for a high number of cases of occupational asthma reported across all EU Member States. One member of the group – methylene diphenyl diisocyanate (MDI) and its isomers – is already subject to a restriction when used as a component of consumer products (REACH Annex XVII, No. 56).

Discussion of appropriate measures on risk minimisation

In 2014, the Federal Institute for Occupational Safety and Health (Deutsche Bundesanstalt für Arbeitsschutz und Arbeitsmedizin – BAuA) conducted a Risk Management Option Analysis (RMOA) to examine the need for action and the options surrounding the use of diisocyanates. It concluded that action is needed at European level to limit the risks to workers. For various reasons, an authorisation process was deemed to be unsuitable. For instance, due to a lack of suitable alternatives, there would be many situations when authorisation would be granted, even if safe use could not be guaranteed. The highly branched supply chains in this case would make an authorisation process extremely complicated.

In 2015, the BAuA therefore issued a Call for Evidence to stakeholders to provide information on the use of diisocyanates and possible alternatives. In October 2016, on the basis of the results, it submitted an Annex XV restriction dossier to notify its Registry of Intentions (RoI) to the European Chemicals Agency (ECHA).

Contents of the restriction proposal

The new proposal restricts the use of diisocyanates as substances on their own, as a constituent in other substances or in mixtures for industrial and professional uses and prevents them from being placed on the market for this purpose. This is not a total ban, but rather is linked to the fulfilment of certain criteria, which ultimately entails stricter handling and is intended to ensure that there are no risks to health through exposure.

In other words, either the product must be designed or packaged to minimise worker exposure in use, or workers must be so well trained that they themselves are able to detect and avoid the risk of exposure. In its justification, the BAuA also points out that the available workplace limits are not suited to ruling out the development of respiratory allergies. The exposure of workers must therefore be minimised as far as possible by the measures described. The proposal restricts the marketing and use of monomeric diisocyanates on their own or as constituents of mixtures for industrial or commercial use, unless

a. The cumulative concentration of diisocyanates is less than 0.1% by weight or

b. The substance or the mixture, in the form in which it is supplied to the user, meets the requirements of Annex 12 or

c. Prior to use, the employee or self-employed worker has completed appropriate training in accordance with Annex 13 and taken measures.

Those who place products containing diisocyanate on the market would, where appropriate, have to prove in accordance with Annex 12 of the restriction proposal that there is very little potential for exposure in the intended use. Upon request, a corresponding document must be supplied within 10 days to the competent authority of the Member State in which the product is placed on the market (in English or an official language of the Member State).

Annex 13 describes measures and information that must form part of any training, which workers must undergo before they are allowed to handle diisocyanates. The measures are divided into three groups and build on each other. The groups include technical and organisational measures and personal protective equipment. Each group entails four hours of training, which must be refreshed every four years. The products’ suppliers are obliged to create appropriate training materials in the language of the respective Member States in which they market the products.

Next steps at EU level

The submission of any restriction proposal triggers a formal process at EU level. ECHA has already initiated a 6-months public consultation process. Here, stakeholders are invited to comment on the proposal from scientific and socio-economic perspectives. The deadline for commenting is 1 June 2017.

At the same time, the committees of ECHA, namely the Risk Assessment Committee (RAC) and the Committee for Socio-Economic Analysis (SEAC), are preparing their opinions. These opinions will again be subject to a public consultation process, which will last two months this time. Finally, the European Commission will present a draft regulation, which will be agreed in committee with the participation of the Member States.

It will be several years before a corresponding restriction comes into effect. However, companies should monitor the process of restriction closely, assess the impact on their own activities and products, and, where appropriate, make use of the options provided for commenting.

http://www.european-coatings.com/Raw-materials-technologies/Proposed-restriction-of-diisocyanates