Compressed Air Testing – Microbial and Contaminant Limits

Hello All,

I am just having some trouble finding information. What would be the max limit for microbes in a compressed air test? Also, the limits for oil, water, and particulates? We are a dry, NRTE facility and compressed air is used for daily cleaning as well as rejection of defective products. Any help would be appreciated.

Thanks!

I would look up ISO 8573-1:2010, e.g., here: https://webstore.ans...saAqOoEALw_wcB 

It looks like there is a British Standard version but it looks like you are in the United States. As far as I can tell, it looks like the standard has not been updated since 2010.

Anyway, you have some choices to make:

Particles: Table 1 in the document is compressed air purity classes for particles. You need to choose a purity class, presumably based on risk. It will assign a maximum number of particles per cubic meter as a function of particle size.

Humidity and liquid water: Table 2 in the document is compressed air purity classes for humidity and liquid water. You need to choose a class, and it will assign the pressure dewpoint that the air must be equal to or below.

Oil: Table 3 in the document is compressed air purity classes. You choose the class, and from that it assigns a concentration of total oil that the air must be equal to or below.

So, therefore, it all comes down to risk, and the purity class that you assign based on that risk. The risk will be based on factors such as whether the compressed air contacts product or product-contact surfaces or other high-risk surfaces. I hope that helps.