Disputes over trade and environment are not seldom superficial and the ongoing debate on the Transatlantic Trade and Investment Partnership (TTIP) is not an exception. This article, however, seeks to provide an in-depth analysis in one of the areas being negotiated, namely chemicals management. It is shown that both policy and legislation in the area differ fundamentally between the EU and the USA, so neither harmonization of laws, nor harmonization of the implementation of laws is concluded to be plausible. Similarly, the prospects to harmonize the development of future chemicals legislation are concluded to be less than modest, and any institution for transatlantic regulatory collaboration in the area risks causing a regulatory chill effect at the expense of public health and the environment. The exception would be if US legislators would strengthen policy to the EU's higher level of precautionary protection, but such a policy change has for a long time proved impossible in the chemicals area.