The latest revision to the Swiss Chemicals Ordinance, enforced in May 2022, brought about substantial changes to the definition of existing substances. Since then, the definition of existing substances in Switzerland depends upon the registration status of the substance in question under EU-REACH regulation. All substances that do not meet the definition of existing substances are considered new substances and are in principle subject to notification before they are placed on the Swiss market. Exemptions are coherent with those of REACH, e.g., for quantities of less than one tonne per year. A notification requires the submission of a data set corresponding to the one for a registration under REACH. Substances already on the market before the entry into force of the revision, which became new substances according to the modification, will have to be notified under the transitional provisions in order to continue to be placed on the market. On the contrary, the notifiers of already notified substances, which are now existing substances, are exempt from their obligation to provide information and updates. This revision also amended the language requirements for labelling and introduced facilitations for the reporting of preparations.