The liquid is almost always methylene chloride, but some early bubble lights used a lightweight oil.
In the European Union, the European Parliament voted in 2009 to ban the use of DCM in paint-strippers for consumers and many professionals.
In 2009, the Taiwanese Environmental Protection Administration Executive Yuan (EPA) found that the soil and the groundwater in the area close to Formosa Plastics' Renwu Plant has been polluted by benzene, chloroform, dichloromethane, 1,1,2-Trichloroethane, 1,1-dichloroethylene, tetrachloroethylene, trichloroethylene, and vinylchloride.