Hygiene and Sanitation
This domain tests how to prevent contamination through personal hygiene, cleaning, sanitation, pest control, water quality and waste management. Expect practical cleaning sequences and concentration calculations.
Core concepts
- GMP and GHP: good manufacturing and hygiene practices cover premises, personnel, equipment, water, pest control and waste.
- Cleaning cycle: dry cleaning, pre-rinse, detergent wash, rinse, sanitising and drying. Sanitisers work poorly on dirty surfaces.
- Personal hygiene: clean uniform, hand washing, head covering, no jewellery, no eating in production areas and exclusion of ill workers.
- Pest control: proofing, inspection, baiting and waste removal; chemicals must not contact food.
- Water and waste: potable water for food contact; segregate wet and dry waste and prevent cross-contamination.
Worked example
To prepare 200 L of 200 ppm chlorine solution from 5% bleach: 5% = 50,000 ppm. Required bleach volume = (200 L × 200 ppm) ÷ 50,000 ppm = 0.8 L. Add 0.8 L bleach to about 199.2 L water and mix. The reasoning is a dilution balance: concentration × volume before equals concentration × volume after.
Traps
Sanitising before cleaning; mixing chlorine with acid; using unpotable water; storing chemicals near food; assuming a strong smell means effective cleaning; ignoring hand-contact surfaces and drains.