Control Sample?

I have a customer who I did some air samples for a couple of months ago who had abatement completed. Know he wants me to come back and re-test. Question, can I re-use the exterior control sample as my baseline or do I need to take a new one? I was not sure how to answer this. To me it seems that it should be OK. Your thoughts.

Take a new one

New, ALWAYS… Especially as your “control” is from (dry) Summer, and we are now in transition to (wet & cold) Autumn.

Gotcha, Customer was trying to be conservative.

Completely understand, but there are Professional Protocols involved that we must (should) always adhere to.

The purpose of the outdoor (control/baseline) sample is so that you can identify the difference between what you find inside to outside. Since the mold spors in the outside sample vary all the time using an older outdoor sample is not the way to go.

yes, a new control sample is a must, agree with above posters.

Yes an new control, most of the time. IIRC Alberta guidelines state that an older control can be used if it is within 30 days of prior testing, anything past that needs a new sample.

Follow the SOP for whomever you are certified from. Most require 2 exterior samples per visit to be collected(1 on each side of the home) and that is what you will judged on if you ever have to stand in front of the man. Trust me on that one. You need to always collect a new exterior sample per visit.

On another note, its gotta be too cold to sample in Minisotta at this time of the year. Recheck your sop’s. No sampling below 33 degrees.

It wasn’t on Oct. 2nd when Ron originally posted.

Did the abatement contractor do any sampling after they were done?

Jeff Wicklander