Hello. My company has just purchased an air compressor and a nitrox maker so we can fill our own tanks. Until now we have been getting our tanks filled by another local shop. The air compressor is Coltri and the nitrox maker is from Nuvair. My questions are, what are the requirements for testing the air quality coming from the compressor? How often does this need to be done? I've seen once every 6 months and I've also seen people say once every quarter. What body does the requirement come from? OSHA? CGA? I've read that PADI used to require it but no longer does (we are a PADI Dive Center). OSHA has a thread on their website but it was dated from the 70's and 80's so I was hoping to find some updated information. I've emailed Trace Analytics and asked them, but have not heard back from anyone. I was hoping someone here would be able to help me with getting some solid answers or help point me in the right direction to find them. Thank you!!