The subject invention relates to broadband optical metrology tools for performing measurements of patterned thin films on semiconductor integrated circuits. A bulk tank contains a supply of LNG which is pumped to a smaller storage tank. Furthermore, the present invention relates to the use of the transfection agent according to the invention for producing a drug for gene therapeutic treatment of humans and animals. A part of the liquid used in the liquid ring pump is bled off to final destruction different than the final incineration equipment in oxygen excess environment.