Norwegian to English Science Textiles / Clothing / Fashion Gas masks, chemicals

Organiske gasser og damp med kokepunkt over 65oC, f.eks løsemidler som lakknafta og tolven.

Organic gases and vapors with a boiling point over 65oC, such as solvents like naphtha and "the twelve".

Obviously it's not really "the twelve", but what is it referring to? I can't find it anywhere.

This is from a protective work clothes catalog, in the respiratory protection section. It's talking about what type of protection different color labels indicate.