This document provides questions, answers, and summaries related to NEBOSH Unit-IB on chemical control, toxicology, and epidemiology. It includes:
1. Questions on human epidemiology and animal studies for investigating carcinogenic substances.
2. A question calculating the respirable crystalline silica exposure from sampling data.
3. Questions on the structure of skin, contact dermatitis, and advice for preventing dermatitis in a hair salon.
4. A question identifying where different grades of an industrial chemical powder may deposit in the respiratory tract.
5. Questions on how the body defends against inhaled dusts and controlling powder exposure during mixing.
6.