While experts can sometimes determine which type of mold is growing on a surface by its appearance, they turn to laboratory testing to make the final determination. Most people recommend calling experts to inspect the mold, but homeowners can also collect their own samples to send to a laboratory.
While black mold is perhaps the best-known type of toxic mold, it's not the only dangerous mold. As a result, homeowners who look for signs of black mold generally can't know for sure whether a particular mold is dangerous or not without training and experience.
Home testing kits come with instructions on how to collect mold, and they come with appropriate packaging to ship samples to a lab. It's important to collect the mold safely; masks can block mold spores that may be released while the mold is agitated. Gloves can also prevent contaminating other parts of the home and the sample itself.
Homeowners also need to make sure they've found all the mold that has infected their home, and most homeowners don't know everywhere mold can grow. Hiring an expert allows homeowners to know that there is no dangerous mold left undetected and untreated after removal of the visible patch.