FOOD-GALLEY-2.2.1

The Four Routes of Contamination and How to Break Them

Contamination is microbiological, chemical, physical or allergenic, and cross-contamination usually runs from raw to ready-to-eat via hands, equipment, cloths and surfaces. It is broken by separation, sequence, colour coding and cleaning.

The galley is two metres wide. The chef is boning a chicken at one end of the bench; you need to plate a caprese at the other. There is one board free, one sink, and eight minutes. Everything that can go wrong in food safety is about to be decided by what you do next.

The four types of contamination

Type Examples Prevention
Microbiological Bacteria, viruses, moulds from raw food, hands, cloths, pests Separation, temperature control, hygiene, cleaning
Chemical Cleaning chemicals, sanitiser residue, pesticides, machine oil, fuel, descaler Store chemicals away from and below food, correct dilution, rinse, never decant into food containers
Physical Glass, metal, bone, packaging, plasters, hair, fingernails, jewellery, pest bodies Cover food, no glass near the galley, blue detectable plasters, tidy work, check equipment
Allergenic Traces of nuts, milk, gluten and the other regulated allergens in a dish declared free of them Separate storage and equipment, dedicated preparation, truthful information

Cross-contamination is the transfer of hazards from one place to another - usually from raw to ready-to-eat. It is the single largest controllable cause of food poisoning.

The vehicles that carry it

  • Hands - the number one route.
  • Equipment: boards, knives, tongs, slicers, vac-pack machines, mixers.
  • Cloths and sponges - a warm, wet, food-soiled cloth is a bacterial incubator. Use disposable or laundered colour-coded cloths.
  • Surfaces: benches, sinks, fridge shelves, handles, taps, tablet screens.
  • Food touching food: raw meat dripping onto salad; that is why raw sits below ready-to-eat.
  • Pests, waste and dirty packaging brought aboard with provisions.

The four defences

  1. Separation - physically separate raw and ready-to-eat food at every stage: storage, preparation, cooking, service. Raw meat and fish always on the bottom shelf of the fridge, in sealed containers, below anything ready to eat.
  2. Sequence - if you cannot separate in space, separate in time. Do all ready-to-eat work first, on a clean bench, then all raw work, then a full clean-down. Never the reverse.
  3. Colour coding - the widely used catering scheme for boards, knives and cloths:
Colour Use
Red Raw meat
Blue Raw fish
Yellow Cooked meat
Green Salad, fruit and vegetables
Brown Vegetables (root/dirty)
White Bakery and dairy
  1. Cleaning and disinfection - the correct process between tasks, with contact time respected, plus handwashing at every change of task.

The chemical trap

Never store cleaning chemicals above food, never keep them in unlabelled bottles, and never leave a sanitiser to pool on a surface that food will touch without observing the product instruction for rinsing. Sanitiser in a soup ruins a charter as surely as Salmonella does.

Onboard Notes

Space forces short cuts, so decide the sequence before you start: on a small yacht the two-bench rule becomes a two-time rule. Keep a strict rule that provisioning boxes and outer cardboard never come into the galley - cardboard carries pests, dust and dock filth; decant into clean crates at the passerelle. Watch for the yacht-specific physical hazards too: stainless swarf, broken glassware in a seaway, engine-room rags, and hair from a crew member who has been on deck all morning.

Scope note: xplor is not an approved centre or an accredited training provider. This lesson is preparatory study only - no certificate and no regulated qualification is awarded here, and the Level 2 food safety award must be sat and assessed with an approved centre of a regulated awarding organisation.

Practice questions

5 questions
recallcore

recall · core

Name the four types of contamination and give an example of each.

recallcore

recall · core

List the standard catering colour codes for boards and knives.

recallcore

recall · core

What are the main vehicles of cross-contamination in a galley?

scenariostretch

scenario · stretch

The galley is two metres wide, the chef is boning chicken at one end, and you must plate a caprese salad at the other. There is one free board and eight minutes. What do you do?

oralstretch

oral · stretch

Talk me through how chemical contamination happens onboard and how you prevent it.

Independent study. xplor is not an Ofqual-regulated awarding organisation or an approved centre, and awards no qualification. Covers the ground assessed at Level 2 food safety in catering; the regulated award itself must be sat with an approved centre.

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