Toxicology, Human Exposure, and Personal Protective Equipment
Toxicology, Human Exposure, and Personal Protective Equipment
This domain tests basic toxicology and how to select and use PPE from the label, not from habit.
Core rules
- Acute toxicity is measured by LD50 (dose) or LC50 (air concentration); lower values mean more toxic.
- Routes of exposure: dermal, inhalation, oral, ocular. Dermal is often the largest workplace route.
- Signal words: DANGER-POISON with skull and crossbones for highly toxic; DANGER for corrosive/skin or eye damage; WARNING; CAUTION.
- Chronic effects can include cancer, reproductive harm, and cholinesterase inhibition.
- PPE is product-specific: gloves, coveralls, footwear, eye/face protection, respirator. Chemical-resistant gloves are not automatically any glove.
- Fit-test respirators; wash hands before eating, drinking, smoking, or using the toilet.
- Remove PPE without touching contaminated surfaces; wash outside PPE before removing.
Worked example
A label says "DANGER" with corrosive hazard, requires chemical-resistant gloves, goggles, and a respirator. A worker arrives with cotton gloves and safety glasses. Reasoning: cotton absorbs and holds liquid; safety glasses do not seal. The label requires the specified protection. Stop, get the correct gloves and goggles/respirator, fit-check the respirator, and document training.
Traps
- Assuming more PPE is always safer; heat stress matters.
- Reusing disposable gloves.
- Wearing leather boots with an EC that soaks in.
- Skipping handwashing before a break.
- Using a dust/mist mask for a vapor.