Acceptable Refrigerant Contamination Levels

I recently sent out an R-114 refrigerant sample for analysis, and the vendor replied that we had excessive acid, moisture, and high boiling point impurities (HBI) (4.9 ppm acid, 169 ppm water, and 1.70% HBI). They recommended that we recycle the refrigerant, and change all filters/driers/desiccants. The current maintenance strategy for this chiller would not have us performing these activities for another year (last done January 2016), so I am trying to determine if the vendor is being overly conservative. Are there any standards/documents that discuss acceptable refrigerant contamination levels? All I can find is AHRI Standard 700 which gives acceptable levels for new/reclaimed R-114 (1 ppm acid, 10 ppm water, and 0.01% HBI). I saw ASHRAE Standard 63.2 talking about a "standard contaminated refrigerant sample" which, for R-114, contained 85 ppm water, 200 ppm acid, and 20% HBI; this standard centers around filtration capacity though, so I'm not sure how "standard" their numbers would be for actual equipment. This post is specifically about a 30+ year old 230 ton Carrier 19EA semi-hermetic centrifugal chiller using 2400 pounds of R-114, but I have R-11 and R-134a chillers running with contaminants above AHRI 700 purity standards too.

So where do you folks get your acceptance criteria for refrigerant samples, and how strictly do you obey them? Would you be shutting your chiller down early to recycle the refrigerant and/or change the filters if your sample didn't meet AHRI 700 standards, or do you follow other guidelines?

I would say change filters as a minimum and re-evaluate after 3 months. I was recently at a IOR technical presentation about refrigerant quality/contamination and to a seasoned veteran it was eye opening. If I was you I would take a sample of the vendors new and or cleaned refrigerant and send it away for independent evaluation. Beware though of inducing your own contaminants into the sample/s