Hazards and hazard analysis

A hazard is anything in food that could make it unsafe and cause harm to the person who eats it. That is the whole definition, and the test it gives you is simple: if it could hurt the customer, it is a hazard. This is deliberately broad, because the point of hazard analysis is to catch everything that could go wrong before deciding what to do about it. A hazard does not have to be dramatic or unusual. The bacteria on a raw chicken, a fragment of glass from a broken jar, a splash of sanitiser left on a surface, and a trace of peanut in a dish sold as nut free are all hazards, and all of them are ordinary things that turn up in real food businesses every day.

Every hazard you will meet falls into one of four types, and you already know them from Level 1. Biological hazards are living things, meaning bacteria, viruses and moulds, and they are the most common cause of food poisoning. Chemical hazards are substances that should not be in food, such as cleaning products, sanitiser, machine lubricant and pest treatments, and they usually reach food because chemicals were stored or used near it. Physical hazards are solid objects, such as glass, metal, plastic, bone, packaging debris and hair. Allergenic hazards are allergens appearing where a customer does not expect them, and for a person with a serious allergy a trace can be life threatening, which is why allergens are treated as a hazard in their own right. In a hazard analysis these four become a checklist. At every step of the process you ask, one type at a time, could a hazard of this kind appear here.

This is the distinction that most people blur, and getting it right is worth real effort because Level 2 tests it directly. A hazard is the potential to cause harm. A risk is how likely that harm is to happen. Take raw chicken. The salmonella it may carry is the hazard, and that potential is present the moment the chicken arrives, whether or not anyone ever falls ill. The risk is the chance that the harm occurs, and that is something you can change. Cooking the chicken to a 75 degree core drives the risk down close to zero, even though the hazard was there all along. This is exactly how HACCP works: you cannot usually remove a hazard from existence, but you can control it by driving its risk down to a safe level. A hazard analysis lists every hazard and then judges the risk of each, so that the most likely and most serious ones get the tightest control, and effort is not wasted equally on things that matter and things that barely do.

The heart of a hazard analysis is that it examines the process one step at a time, instead of looking at the finished food and forming a general impression. The reason is shown in this lesson's central diagram: different hazards arrive at different steps. At delivery, the hazards are bacteria arriving on raw ingredients and physical contamination from packaging. In storage, the main hazard is bacteria multiplying if the temperature is wrong. In preparation, cross-contamination and allergen transfer become the concern. At cooking, the hazard is undercooking that lets bacteria survive. At service, it is bacteria regrowing if food is held warm too long, or chemical residue from a surface cleaned badly. No single check at the end could catch all of these, because they are different problems at different moments. That is why the process is mapped step by step, and why hazard analysis is done on the flow of the food and not on the food alone.

A hazard analysis comes down to three moves. First, list the steps, mapping the whole process the food goes through from delivery to the customer. Second, find the hazards, going to each step and asking which biological, chemical, physical or allergenic hazards could appear there. Third, judge the risk, deciding how likely and how serious each hazard is so that the important ones get the tightest control. This is Principle 1 of HACCP, the principle every other one depends on, because a hazard you never identified is a hazard you can never control. It is worth noticing that the food handler contributes to this without necessarily writing the plan. The people who know a step best are usually the people who work it, so their knowledge of what goes wrong on the floor is what makes a hazard analysis realistic instead of theoretical.

A hazard analysis walks the process one step at a time and asks the same question at each step, which of the four types could appear here. On the process in this exercise the answers are these. Delivery brings biological hazards on raw meat and physical hazards from packaging and delivery boxes. Storage brings biological hazards, because bacteria multiply if the temperature is wrong. Preparation brings biological hazards through cross-contamination and allergenic hazards through allergen transfer between foods and surfaces. Cooking brings biological hazards, because undercooking lets bacteria survive the step that was supposed to destroy them. Service brings biological hazards through regrowth if food is held badly, and chemical hazards from sanitiser residue on surfaces and equipment. Notice that biological appears at every step while the other three appear at some and not others. That is the reason the analysis is done step by step. Judging the process as a whole would miss the steps where a particular type is the one that matters.

The scenario asks you to name what the bacteria on the raw prawns are, and the answer is a hazard, because a hazard is the potential to cause harm and that potential exists the moment the prawns arrive. Calling it a risk is the common slip, because the two words are used loosely in everyday speech, but in HACCP they are precise: the risk is how likely the harm is, which depends on what happens next. Saying it is neither, because the prawns will be cooked, confuses control with absence. Cooking does not mean there was never a hazard, it is the very thing that controls the hazard by lowering the risk. Holding these three apart, the hazard that is present, the risk that can change, and the control that changes it, is the mental model the rest of Level 2 relies on.

The lesson in five lines. A hazard is anything in food that could make it unsafe and cause harm. There are four types of hazard: biological, chemical, physical and allergenic. A hazard is the potential to cause harm, while a risk is how likely that harm is to happen. A hazard analysis examines the process step by step to find the hazards present at each step. And different hazards arise at different steps, which is exactly why the whole process is mapped instead of the finished food being judged as a whole.

This is the second of seven lessons in Level 2, and every lesson is free to watch for as long as you need. When you are ready, the quiz proves what you know and earns a certificate recognised by TrustBite, an independent food safety recognition body. One payment covers the quiz and certificate for all three levels, so whichever level you buy first, the other two are included at no extra cost, and each certificate is valid for three years with renewal at 5 euros. No registration is needed to keep learning, and you only pay when you decide you are ready to be tested. If you are training a team, group options are available for both hospitality and production sites.

You have finished the second lesson of Level 2 and you can now do the first thing HACCP asks, which is find the hazards. You know what a hazard is, the four types it comes in, how a hazard differs from a risk, and how a hazard analysis walks a process step by step. The next lesson pulls back to show the seven principles of HACCP as a whole, and you will see that the hazard analysis you have just learned is Principle 1, the foundation the other six are built on. Every lesson stays free and you can rewatch any of them. When you are ready, the quiz earns a certificate recognised by TrustBite, and one payment covers all three levels.