Certificates show that a process or product was assessed against a standard at a point in time. Always check scope, validity dates and the issuing body, and confirm the certificate covers the exact product you are buying.
ISO 9001 certifies a company's quality management system, not the quality of a particular product. Check the scope statement lists the products you want, and verify the certificate on the certification body's or accreditation body's public register.
CE marking is the manufacturer's declaration that a product meets the applicable EU directives or regulations, such as the Machinery, Low Voltage, Pressure Equipment or Construction Products rules. Ask for the EU declaration of conformity and the technical file reference; for some product groups a notified body must be involved.
UL and FM listings are common requirements for electrical equipment and fire-protection products in North America and for many insurers. Look up the listing number in the issuer's online directory rather than relying on a PDF.