Although it is preferable to avoid all forms of silicones in the environment of bonding surfaces, risk assessment now makes a distinction between the type and form of silicones.
The committee involved in the further implementation of DIN 6701 (standards for adhesive processes for train and tram construction) introduced a refinement in September 2011. In this context, the risk of fully reacted silicones, as well as high-viscosity silicone adhesives, is considered low, provided that direct contamination is prevented.
The necessity of completely avoiding low-viscosity silicones remains, as does the prevention of any possible form of direct contamination.