The 24th August 2023 start date for the REACH training and certification requirements for users of diisocyanates is looming ever closer, impacting the use of many polyurethane adhesives in medical applications. Peter Swanson, managing director of adhesives specialist Intertronics, explains how medical professionals can best prepare for this change.
Following a review by the European Parliament, the REACH Restriction on aliphatic and aromatic diisocyanates was published on 4th August 2020 and became effective on 24th August 2020. The restriction aims to minimise the adverse health effects induced by exposure to diisocyanates at the workplace (including respiratory sensitisation and occupational asthma) and along the entire supply chain.
Polyurethane adhesives and REACH
Polyurethane adhesives are popular in structural bonding for medical devices as they offer good performance characteristics when bonding a range of substrates: they are extremely tough, have high peel strength, offer good environmental resistance, and are suitable for gap filling. They offer commercial and process benefits too, in that they are relatively fast cure, which helps increase productivity and reduce work in progress, while being reasonably low cost.
Polyurethane products, including adhesives and potting compounds, are made by reacting diisocyanates and polyols. Diisocyanates are highly reactive; one of the reasons it is possible to have fast curing polyurethane adhesives. However, this reactivity also means that care must be taken to prevent diisocyanates causing health effects in the people who handle them.
Like any chemical or substance, diisocyanates are safe when they are handled according to the relevant risk management and health and safety measures. Diisocyanates are only used as reactive constituents — they react with the polyol to form the polyurethane product, and are used up during the reaction. Virtually no diisocyanates can be found in completed or cured materials.
Impact on industrial users
As of 24th August 2023, in the UK and EU, training is required for all professional and industrial users of polyurethane adhesives and sealant products with a total monomeric diisocyanate concentration of > 0.1%. All staff who come into contact with a substance containing diisocyanates must be trained and certified ahead of this date, and employers have a responsibility to provide this.
Training programmes are available online in several languages, and are typically either free or low cost. The Association of the European Adhesive & Sealant Industry (FEICA) has committed to financial support for the training for member organisations and their clients, and has shared a voucher code that makes training material related to PU adhesives and sealants applications free of charge for end-users.
Alongside providing the training, employers will be required to collect evidence of its successful completion, such as by storing certificates. Training certificates are valid for five years, after which they need to be renewed.
Micro-emission technology
The cost, administrative, and time burden industrial users of PU adhesives face as a result of the new requirement for mandated REACH training and certification could be significant. To help, there are new polyurethane adhesives available based on micro-emission technology. These materials have a concentration of monomeric diisocyanates which is less than 0.1% by weight, so training is not required if a manufacturer specifies such products.
For example, Intertronics recently launched Point-One polyurethane adhesives, fast-curing two-part adhesives that form strong, durable bonds in as little as 10 minutes. These adhesives are solvent and VOC free, and have no requirement for a carcinogen warning on the product label as they are not H351 classified.
With the 24th August deadline looming, industrial users of PUs have two options, train their team, or opt for materials that require no training. Both approaches enable safe and productive processes for manufacturers using polyurethane adhesives.