The IICRC WRT body of knowledge mandates that EPA-registered antimicrobials (biocides) must be used strictly in accordance with the product label directions. Under U.S. law, the label is considered a legal document, and deviation from label instructions constitutes misuse of a pesticide.
Label directions specify approved application methods, dilution ratios, dwell times, PPE requirements, ventilation needs, and occupant restrictions. The WRT manual emphasizes that technicians are not permitted to alter concentrations, combine products, or improvise application techniques, regardless of perceived effectiveness.
Estimating dilution or increasing concentration does not improve efficacy and may create safety hazards, damage materials, or expose occupants and workers to chemical risks. Combining products can produce toxic reactions, while under-dilution or over-dilution may render the antimicrobial ineffective or unsafe.
The WRT curriculum reinforces that antimicrobials are supplemental tools, not replacements for removal of unsalvageable materials or proper drying. Proper use ensures regulatory compliance, protects health, and limits liability for the restorer.
