In 1964, after an innumerable series of tests at the new research institute in Ainring, the successful development of a novel leak detecting agent was completed. Immediately a patent was filed for this leak detecting agent and sold from 1964 onward under the trademark GASPRUF (today GASPRUF-Paste). Due to it's novel qualities, the leak detecting agent GASPRUF, captured the market by storm.

In 1969, posthumous, Otto Fahsig received the German Federal Patent No. 1 273 863 for the invention of the leak detecting agent. Also today, decades after his development, this leak detecting agent is used to a great extent, i.e., by bulk buyers like the pipe construction, the container construction and the gas service industries.