The process of CE marking
1.
The CE directives (i.e. Machinery Directive 2006/42/EC) are provided in the link to EU commission.
The development team shall evaluate what regulations that is applicable to its product.
https://single-market-economy.ec.europa.eu/single-market/goods/new-legislative-framework_en
Other regulation without the legal document Declaration of Conformity that might apply are REACH
https://www.kemi.se/en/rules-and-regulations/the-reach-regulation
or Food Contact Regulation 10/2011