Clays produced with Coal Tar pitch are already banned in many countries throughout Europe, and these clays are likely to be banned in the UK in the very near future.
Clays produced using Coal Tar have a much lower melting point and this can cause major problems during the hot summer months. The average melting point is 98 degrees for Coal Tar clays as opposed to production using Petro pitch of an average melting point of 115 degrees!