[Old Professer]

Cleaning was done with R19 stable to 88F as a liquid, and R113 stable to 118F.

These two refrigerants were covered with a thin film of water to prevent evaporation and presented minimal flux losses.

[cogitator]

These two refrigerants were covered with a thin film of water to prevent evaporation and presented minimal flux losses.

So I would presume that one of the major industrial sources was foam-blowing? (Not to be confused with the more common public-relations activity known as smoke-blowing.)