TIH stands for Toxic Inhalation Hazard.

• A. Toxic Inhalation Hazard
• B. Transported Industrial Hazard
• C. Temporary Inhalation Hazard
• D. Toxic Industrial Hazard

Answer: (A)

TIH is used to describe hazards that are deadly or highly toxic when inhaled, so the correct expansion is Toxic Inhalation Hazard. This phrasing highlights the route of exposure—the danger is the toxic vapor or gas being breathed in—which is what responders must protect against with proper detection, ventilation, and respiratory PPE. In hazmat practice, TIH is used to label substances like chlorine or phosgene that can cause rapid harm through the air, guiding urgent actions such as evacuation, air monitoring, and prompt decontamination.

The other options don’t align with the established usage: they either omit the inhalation route or use nonstandard terminology, which would not communicate the specific inhalation danger the acronym is meant to convey.