Why did refrigeration engineers seek substitutes for ammonia?

Refrigeration engineers sought substitutes for ammonia because of its significant safety drawbacks. While ammonia is an effective coolant due to its ability to liquefy at low temperatures and absorb substantial heat, it poses a severe risk if it leaks, as it is both unpleasant and toxic.12

To address these safety concerns, engineers searched for alternatives until the 1920s, when synthetic refrigerants such as Freon were developed. These new substances were preferred because they were odourless and nontoxic in most conditions. However, it is important to note that while these synthetic replacements solved the immediate toxicity issues of ammonia, they were later discovered to cause significant environmental harm, specifically contributing to the depletion of the ozone layer.13