L3 Contamination

Hazards & cross contamination
Hazard, Risk & Severity
Physical Hazards

In this chapter
Even the cleanest of kitchens and best ingredients sourced from the most reputable suppliers still contain levels of bacteria. Bacteria are a fact of life and, as we have discovered, they exist in and around every one of us. This chapter introduces you to cross contamination and how this phenomenon can spread bacteria across potentially hundreds of surfaces, people and foods in just a few hours.

Hazard, risk & severity
Your objective is to limit the potential sources of a range of contaminants, hazards, coming into contact with the food. By doing this you dramatically reduce the likelihood of a food poisoning incident occurring.

In the food safety industry, we talk a lot about hazards, risk, and severity. Substances or actions potentially hazardous to health are called ‘Hazards’. The likelihood of it entering or affecting food is called the ‘Risk’. The danger that the hazard can cause is called the ‘Severity’.

Issues to consider at this point:

The variety of hazards that can result in contamination of food
The implications of contamination occurring in your kitchen
How we assess the risk of these hazards contaminating food
What are the practical steps to control hazards and reduce risk
How best to train and supervise your team on these issues
Sources of Contamination
Contamination occurs when ‘an unwanted body enters the food’. Sources of contamination are Physical, Chemical or Biological. Let’s look at the hazards individually:

Physical hazards
Physical contamination occurs when an object falls into or otherwise enters the food. Some physical hazards offer little threat to health low severity but may cause significant customer dissatisfaction. Hair is a physical hazard that also is a bacterial hazard as well.

Unlike most forms of chemical and microbial contamination, physical contamination can usually be seen.

Physical hazards can be classified as being caused by one of the 6Ps:

Product
People
Packaging
Plant
Premises
Pests
Physical hazard 1 – The Product
The actual food ingredients

Examples:
Bone, teeth, shells, dirt, stones, and leaves.

Controls:
Sources ingredients from reputable suppliers with proven supply channels
Check all deliveries for physical hazards immediately they arrive
Visually check, wash food as the first stage of all preparation
Physical hazard 2 – People
Hazards associated with the food handlers including prep, cooking and service

Examples:
Plasters, hairs, fingernails, parts of clothing and various pocket items

Controls:
Appropriate clothing and hair coverings
No eating, drinking or smoking in food preparation areas
Good processes, monitored and enforced by supervisors
Physical hazard 3 – Packaging
Physical hazards entering food from packing

Examples:
Cardboard, staples, polythene wrapping or wood

Controls:
Have separate areas for unpacking, food preparation and cooking
Undertake unpacking as a single event and don’t unpack items during food prep/cooking
Visually inspect ingredients immediately before food preparation begins
Physical hazard 4 – Plant
Items from equipment or machinery used in the kitchen environment

Examples:
Oils, screws, nuts, washers and other small components from machinery as well as oil

Controls:
All oils and greases used in kitchen equipment must be food grade/food safe
Regularly check equipment for signs of loose or damaged items
Immediately remove any damaged or loose equipment parts from the food preparation area
Have a scheduled maintenance programme, don’t just respond to breakdowns
Consider policy of banning, or signing in and out any hazards items, tools & other small items
Physical hazard 5 – Premises
Any hazards connected with the building

Examples:
Pins (notice boards), glass, flakes of paint, other items present in or part of the building

Controls:
Have a scheduled maintenance, cleaning and repair programme
Do not have high-risk physical items in the food areas, eg notice boards that use drawing pins
Ensure lighting has a protective covers in case of breakages
Ensure walls, surfaces and floors are smooth and free from defects
Physical hazard 6 – Pests
Physical hazards resulting from animals, birds or insects and pets as well as pests

Examples:
Animal faeces can be physical and biological hazard, feathers, fur and dirt

Controls:
Take preventative approach to pest control, not just reactive
Consider employing a regular pest control subcontractor
Carry out close inspections of the premises regularly, looking for signs of infestation
Use physical prevention measures including fly screens and doors
Click to go to Chapter 5.1
Hazards & Cross-Contamination – continued
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5.1 Hazards & cross contamination
Chemical Hazards
Biological Hazards
Vehicles of Contamination

Chemical hazards
Chemical hazard 1 – Cleaning and pest control agents
Chemicals used in cleaning, sanitising and disinfecting the kitchen and to help keep them pest free.

Examples:
Sanitiser, washing-up liquid, dishwasher detergent, disinfectant and bleach, fly and insect killer, spray air freshener, rat poison

Controls:
Store chemicals separately from food and preparation areas, preferably in locked storeroom/cupboard
Never use cleaning chemicals in area where food is being prepared or awaiting service
Keep chemicals in correctly labelled containers and train staff to use in a safe manner
Follow manufacturer’s instructions carefully
Chemical hazard 2 – Pesticides & preservatives
Some foods may contain legal and illegal levels of pesticides and preservatives

Controls:
Wash food carefully before use, particularly fresh fruit and vegetables
Always use reputable suppliers that can guarantee levels are within safe limits
Chemical hazard 3 – Perfumes & soaps
Many soaps contain chemicals capable of tainting the food

Controls:
Use un-perfumed soaps for hand washing
Do not allow staff to use strong aftershaves or perfumes
Chemical hazard 4 – Veterinary drugs
Some non-organic meat contains traces of veterinary drugs

Examples:
Antibiotics, growth enhancers

Controls:
Use only reputable suppliers, those where drugs are using sparingly and considerately
Consider sourcing meat from herds that guarantee animal treatment & welfare
Chemical hazard 5 – Metals & chemical reaction
Certain acidic foods and metal pans or mercury thermometers may react and cause metal to contaminate. Ensure there are no lead pipes in your plumbing system.

Controls:
Ensure that utensils and containers are suitable for use with food
Ensure correct pans and utensil are used for each task
Avoid the use of mercury & glass thermometers
Biological hazards
Many physical hazards can be relatively straightforward to identify. Bacterial hazards are more complex and problematic. It may not surprise you to hear that they represent the most likely threats to food safety. And as we have already discovered you cannot fully eliminate bacteria, they are present to some degree even in and on the best ingredients, cleanest kitchens and most professional staff.

Your task therefore is to ‘reduce’ and ‘control’ bacterial hazards to an acceptable level. Reducing bacterial levels reduces the chances of multiplication or cross contamination. You control the risks through appropriate processes, careful supervision, and good decision making.

Bacterial cross contamination
Cross contamination is by far the most common culprit in food poisoning.
Understanding this is one of the most important themes of this course and will play a major factor in controlling food poisoning.

Common causes of bacterial cross contamination:

Personal Hygiene – Poor or inconsistent hand washing and personal hygiene practices
Packaging – Contaminated packaging coming into contact with ingredients
Cleaning – Food preparation areas and equipment not clean and disinfected properly
Practices – Cooked food touching uncooked high-risk foods (or via handling)
Premises – Poor workflow and contact with pests, pest droppings or kitchen waste
Vehicles of contamination
As the name suggests, a vehicle of contamination is the vehicle bacteria uses to move from one contaminated point to another. Bacteria can’t travel, they need a mistake by someone for them to travel, and unfortunately, unknowingly we make these mistakes very often.
Food handlers hands are a very common cause of transfer of bacteria as are utensils, cloths and mobile phones.

The franchise factor
So what should you do? You need to break the chain of contamination. Let’s find out how one of the best QSRs (Quick Service Restaurants) do it:

McDonald’s serves 3.5 million meals a day in the UK. An impressive number of people served. Yet how many food poisoning outbreaks are connected with the McDonald’s brand?
The answer is hardly any. So what is the secret?

Good systems and procedures including a food safety management system
Staff consistently following good practices all of the time
Good cleaning and personal hygiene regimes consistently applied
Creating every dish and doing every task in the same consistent manner, stick to the plan
It is not rocket science, McDonald’s simply never does anything that hasn’t been carefully considered and that has a well-proven process behind it. Whether you supervise in your own restaurant, or in a deli, or works canteen, your mission is to take the lesson of the McDonalds’ operational model and apply it to your own workplace.

10 Essentials of contamination control:
Implement a sound documented food safety management based on HACCP principles
Keep high-risk foods out of the danger zone, 5°C to 63°C
Keep raw and high-risk foods separate every process from prep, through cooking to service
Be obsessive in demanding high standards of personal hygiene
Have a good cleaning schedule and stick to it cleaning and disinfection
Store, chill, freeze and defrost foods properly
Cook to at least 75°C for 2 minutes at the core use a probe thermometer every time. Remember it’s 82°C in Scotland
Use reputable suppliers, test chilled/frozen food temperatures at goods-in
Train your staff so they understand the risks and what’s expected of them
Be a hands-on supervisor; observe, guide, encourage, and police the important stuff
Remember: Think before you act to reduce the risk of cross contamination and if in doubt, wash your hands!