REACh (regulation 1907/2006 – come into effect at 1.06.2007) stands for r(egistration), e(valuation), a(uthorization of) ch(emicals). This regulation is part of the new chemicals act, which shall improve the protection of men and environment against harmful effects of dangerous goods. This improvement shall be accounted for by making the goods distinguishable and preventing the production of these goods.

One important change is the reversal of the burden of proof: Before the regulation came into effect the authorities had the duty to determine the hazardousness of a substance. Now the manufacture has to proof that a substance is not hazardous. The hazardousness of a substance sometimes becomes clear after years or decades. For this reason the categorization of a substance is not final anymore. In case of justified suspicion of unknown hazardousness a substance has to be newly evaluated.

Since the whole supply change is integrated into the regulation, in the future the host has to inform the manufacturer about the destination of the substance. The substance has to registered for a certain application area. This application area and the registration number has to appear on the extended safety data sheet (eMSDS). If the certain application area is not mentioned for the substance it can be newly registered by the host as well as the manufacturer of the substance.

The regulation divides all substances into so-called old existing chemical substances (existed before 18.09.1981) and new existing substances (after 18.09.1981 on the European market). The new existing substances are registered when the regulation inured. The old existing substances had to be pre-registered (until 1.12.2008) by the manufacturer, if they shall be produced further on. The pre-registered substances not necessarily have to be registered. The old existing chemical substances that are not pre-registered can sill be produced during a transition period, depending on the amount produced resp. traded per year and the hazardous of the substance . Substances are classified as new substances, if they were unknown or if they were not registered within the period mentioned above. These substances have to be registered before production, no matter how long they have already been known. It should be noted that polymers are covered by an exception.