Who conducts clearance testing or post remediation verification?

The correct choice is that a third-party indoor environmental professional conducts clearance testing or post-remediation verification. This role is critical in the remediation process because these professionals provide an unbiased assessment of whether the area has been properly cleaned and is safe for reoccupation. They are trained to evaluate the remediation effectiveness and ensure that contaminants have been adequately reduced to safe levels.

Engaging a third-party professional helps to minimize potential conflicts of interest that could arise if the original cleaning crew were to evaluate their own work. This independent verification is essential, especially in scenarios involving hazardous materials, to promote trust and ensure compliance with health and safety standards.

While the other options might be involved in the remediation process at different stages, they do not possess the same level of impartiality and specialized training as a third-party indoor environmental professional, making them less suitable for conducting clearance testing.