A chemical product containing a preservative is a treated article according to the definition of the Biocide Regulation. According to article 58 of the Biocide Regulation EU 528/2012 the label of a treated article shall provide the following information:
(a) a statement that the treated article incorporates biocidal products (the preservative);
(b) the name of all active substances contained in the biocidal products (the name of the preservative);
Besides, the preservative must be approved for PT6, in-can preservative. The statement referred to under (a) does not apply to preservatives which are still in the registration process and for preservatives for which no “article 58 statement” obligation has been adopted in the official authorisations.
Finally, preservatives coming from a raw material, carry-over, shall not classify the product as a treated article. These “residual” preservatives need not be mentioned. (European Commission, Notes of guidance, Sept. 2014)
We advise to gradually adopt your labels where applicable.