EU Siloxane Evaluations

In Europe, siloxanes are assessed under the chemicals framework, REACH. They have come under scrutiny because of a suspicion that some of them may be PBT (Persistent, Bioaccumulative, Toxic) or vPvB (very Persistent, very Bioaccumulative). However, the European criteria for assessing whether a substance is PBTor vPvB do not allow for accurate evaluation of the unique and hybrid nature of siloxanes. In fact, many leading scientific experts believe that current regulations define PBT in terms of overly rigid laboratory criteria that are based on the state of the science in the late 1970s and early 1980s, and do not reflect what is observed in the environment.

Restrictions (personal care)

Following a scientific assessment of the substances for possible PBT and vPvB properties by the United Kingdom, a restriction on the use of D4 and D5 was adopted under the European Union’s Chemicals management program (REACH) in May 2017.

The scope of the restriction is limited to wash-off cosmetic products with a D4 or D5 concentration equal to or greater than 0.1% by weight of either substance. All actors that place on the market products that are within the restriction scope must comply with the requirements set forth in this restriction by January 31, 2020. 

In response to this restriction, the silicones industry set up a large-scale Wastwater Treatment Plant (WWTP) monitoring program to help assess the effectiveness this restriction in reducing D4 and D5 down-the-drain emissions. Preliminary monitoring results indicate that D4 and D5 wastewater treatment plant influent concentrations are well below the baseline levels predicted, and in the case of D4, already consistent with the predicted post-restriction concentrations.

In April 2017, the European Chemicals Agency (ECHA) published its intention to assess the need for further restriction of D4 and D5 in leave-on personal care products and other consumer/professional uses (e.g. dry cleaning, waxes and polishes, washing and cleaning products).

In January 2018, the Commission requested adding D6 to the scope of this restriction, and to the scope of the ‘wash-off’ restriction. The restriction proposal on D4, D5, and D6 in leave-on products, as well as the addition of D6 to the ‘wash-off’ restriction is likely to be published in January 2019.

The proposed restriction has not yet been finalized nor approved and may be further amended based on additional information provided, subsequent public consultation or the opinion of ECHA’s Committees.

Substances of Very High Concern

Following a Risk Management Option Analysis (RMOA) of D4 and D5 in late 2017, Germany concluded that these substances meet the REACH criteria for PBT and vPvB and should be identified as Substances of Very High Concern (SVHC). In parallel, the Commission requested ECHA to develop a similar SVHC dossier for D6, based on the ECHA PBT Expert Group’s conclusion that D6 should be considered a vPvB substance.

Although a weight-of-evidence approach applied to all the available data shows that there is no cause for concern, the European Union Member State Committee added D4, D5, and D6 to the list of SVHCs in June 2018. The silicones industry maintains that the EU decision does not consider the whole body of scientific evidence and will ultimately put at risk numerous beneficial uses of silicones in key segments of the economy. In practice, the SVHC nomination does not have any implications for the use of D4, D5, and D6. An SVHC listing is not a ban on the use of silicone polymers. Nor is it a ban or a restriction on the use of D4, D5 and D6. Silicone polymers can be used safely in all products.

Formal identification of PBT/vPvB properties carries communication and risk management measure obligations. The complexity of this information varies according to the actors in the supply chain. More information on these obligations can be found on the ECHA website.

The silicones industry is working closely and on an ongoing basis with the value chain, the Commission, ECHA, and the authorities in European countries to encourage the use of updated PBT criteria and a weight-of-evidence approach for chemical assessments. The silicones industry strongly believes that the use of updated PBT criteria and a weight of evidence approach will provide the most accurate environmental assessments of D4, D5, and D6.