The Mobile Air Conditioning Society (MACS) has issued an urgent warning regarding R134A supplies.
The warning pertains to the possible contamination of R134 refrigerant cylinders. They recommend testing all cylinders with a reliable tester that are expected to be pure R134 to confirm that it is. According to several reputable sources, many cylinders have been found to be contaminated with and have counterfeit labeling.
This can be more serious than just a case of the refrigerant not working. There have been fatalities reported due to this issue. Most reports of contamination come from refrigerants coming from overseas. The most frequent contaminant has been found to be R-40 (Methyl Chloride). This is the worst possible contaminant. This compound is very flammable, toxic, and highly reactive when it is combined with aluminum. This is where the safety concern occurs. Any system that contains aluminum could lead to catastrophic consequences.
Some 30 lb. R134A containers have also been found to contain some R-12 and R-22 as well. All cylinders must read 100% on any approved refrigerant tester. Some contaminated cylinders were found to contain up to 40% of non R134A contaminants.