Biological contaminants are unwanted materials of biological origin, such as microorganisms or material from animals and plants, in a particular environment.
What this means at your property
After a plumbing backup, an assessor needs to understand the source and affected surfaces before proposing cleanup. The general label does not identify every organism present, and visible cleanliness does not establish the absence of contamination.
Should every concern lead to the same laboratory test?
No. Ask what specific question sampling would answer and how the result would change the work. Describe the event and affected locations rather than assuming that a single test represents the entire building.