Waste disposal and pest control
Segregate, store and remove solid waste daily, trap grease before liquid waste leaves the drain, and keep pests out by integrated pest management.
Types of waste in a food unit
| Waste | Examples | Disposal |
|---|---|---|
| Wet (biodegradable) solid waste | Vegetable peels, plate waste, tea leaves, eggshells, spoiled food | Composting, vermicomposting or biogas, or daily handover to the local body's wet-waste collection |
| Dry solid waste | Cardboard, paper, tins, glass, plastic packets and bottles | Clean, sort and send to authorised recyclers |
| Hazardous waste | Empty chemical and pesticide containers, batteries | Keep separate; return to the supplier or give to an authorised handler; never reuse for food |
| Used cooking oil | Oil left after repeated frying | Never pour into drains; give to authorised collectors who make biodiesel (FSSAI's RUCO, Repurpose Used Cooking Oil) |
| Liquid waste | Dishwash and floor-wash water, water carrying fat, oil and grease (FOG), cleaning chemicals | Screens and gratings, grease trap, then the sewer; large factories treat it in an effluent treatment plant before discharge |
Rules for handling solid waste
- Segregate at source into wet, dry, sanitary and special-care (hazardous) waste, often green for wet and blue for dry, as the local body directs.
- Use lidded, foot-operated, lined bins that are easy to clean, and keep the lids closed.
- Empty bins at least daily and before they overflow.
- Keep a separate, covered waste area away from food stores, preparation and service areas, so pests are not attracted.
- Wash and sanitise bins after emptying; do not carry waste through areas where food is open.
- Reduce waste: plan quantities, rotate stock first-in first-out (FIFO), and donate safe surplus food through food-recovery groups.
- Keep records of waste removal and contracts with collectors.
Liquid waste and drains
Liquid waste from washing, cooking and cleaning carries fat, oil and grease (FOG), food bits and chemicals. Kitchen drains should slope away from food areas, have gratings or covers, and be cleaned daily; open, dirty drains invite flies, rats and cockroaches. A grease trap (fat trap) holds greasy water so the fat cools, floats and is held back; it must be emptied regularly or it overflows and smells. Toilet sewage must never join kitchen drains, and there must be no backflow into sinks. Large units such as dairies and meat plants run an effluent treatment plant: primary treatment (screening, settling, oil skimming), secondary treatment (biological, e.g. activated sludge) and tertiary treatment (filtration, disinfection), and must meet the State Pollution Control Board's conditions before discharge.
Common pests: signs and harm
| Pest | Signs | Harm |
|---|---|---|
| Rats and mice | Droppings, gnawed sacks and wires, grease smears along walls, burrows | Contaminate food with urine and droppings; spread leptospirosis and Salmonella; eat and spoil stores |
| Cockroaches | Live or dead insects, egg cases, pepper-like droppings, musty smell | Carry germs from drains to food; trigger allergies |
| Houseflies | Flies around waste and food; maggots in bins | Carry germs of typhoid, cholera and dysentery on their legs and bodies |
| Stored-grain insects (rice weevil, khapra beetle, flour beetles, grain moths) | Holes in grain, webbing, powdery residue, insects in flour | Loss of weight and nutrients, heating and mould, insect fragments (a physical hazard) |
| Birds | Droppings, feathers, nests in roofs and vents | Salmonella and other germs; physical contamination |
Integrated pest management (IPM)
IPM combines several methods. Chemicals are used only when needed, and only by trained people.
- 1Deny entry: wire mesh on windows and vents, self-closing doors, air or strip curtains, sealed cracks and pipe holes, rat guards.
- 2Deny food and water: cover food, clean spills at once, store grains in sealed bins, fix leaks, keep waste covered.
- 3Deny shelter: store goods on racks or pallets off the floor and away from walls; remove clutter and old cartons; rotate stock FIFO.
- 4Inspect incoming goods and reject torn, wet or infested sacks and cartons.
- 5Monitor: regular checks, sticky traps, rodent bait stations marked on a site map; UV fly-killers placed away from open food.
- 6★Control: physical methods first (traps, glue boards); then registered pesticides and gel baits applied by a licensed pest control operator, with food removed or covered.fumigation of grain stores only by trained, licensed persons
- 7Record and review: keep service reports, trap counts and corrective actions.
★ one-way, controls the pace
In a hostel or hospital food store, sacks of rice and dal kept on pallets away from walls, FIFO rotation and a regular service by a licensed pest control operator keep out weevils and rats. Empty chemical containers are never reused to store food.
2 marks: “What is a grease trap?” A chamber in the kitchen drain line that holds greasy water so the fat cools, floats and is held back, preventing blocked and smelly drains; it must be emptied regularly.
5 marks: “Explain the disposal of solid and liquid waste in a food establishment.” Types of waste; segregate at source; lidded bins, daily removal, separate waste area; composting, biogas, recycling, used oil to biodiesel; liquid: sloped covered drains, screens, grease trap, effluent treatment plant.
10 marks: “What is integrated pest management? Explain the methods of pest control in a food unit.” Define IPM; common pests with signs and harm; deny entry, food and shelter; inspect goods; monitor; physical then chemical control by a licensed operator; records.
IPM is keep out, starve out, check, then treat: deny entry, deny food and shelter, monitor, and only then use chemicals. Waste is segregate, cover, clear daily.