FACT SHEET #19 Biological Hazards Biological hazards are organisms, or substances produced by organisms, that pose a threat to human health. They are a major concern in food processing because they cause most food borne illness outbreaks.

Risk Major biological hazards

These organisms can affect human health, including • Bacteria ex: Salmonella spp., Enterohaemorrhagic infection, intoxication and even death. Infection Escherichia coli, Campylobacter jejuni, Yersinia occurs when organisms invade the host and multiply enterocolitica, Listeria monocytogenes, Bacillus in the body. Intoxication occurs when bacteria anthracis, Bacillus cereus, Staphlococcus aureus, produce toxins that affect the body. Clostridium botulinum, Clostridium perfringens, Vibrio vulnificus, Vibrio parahaemolyticus Infection can be prevented by properly processing • Virus ex: hepatitis A virus, Norwalk viruses, and handling food products because pathogens Rotavirus are easily destroyed by heat. However, some bacteria that produce spores can survive cooking • Parasites ex: Toxoplasma gondii, Cryptosporidia, temperatures. Giardia spp., Trichinella spiralis, Taenia solium, Anisakis spp. For example, steam cooking significantly reduces non-spore-forming food borne pathogens, but only Sources inactivates spores. Examples of spore forming bacteria include Bacillus cereus, Clostridium The major sources of biological contaminants in food botulinum and Clostridium perfringens. are: • animal guts: faecal contamination Toxins are produced when toxin producing bacteria are present in high numbers. Bacteria must first grow • soil and water contaminated by non-treated in the food before producing toxins. These toxins manure are very difficult to eliminate. They survive normal • cross contamination: cooking temperatures and even temperatures higher ––human contamination due to poor personal than 80°C (176°F). hygiene, faecal contamination, failure in infection The risk of intoxication is prevented by controlling control (illness not reported) the growth of toxin producing bacteria. These ––cross-contamination of food products spread from include: Clostridium botulinum, Bacillus cereus, and processing environment due to poor/improper Staphylococcus aureus. sanitation

Aussi disponible en français. Factors affecting the growth of Control and prevention microorganisms in foods The most effective way to control biological hazards • The temperature values for microbial growth is by prevention. The implementation of Good depend on the type of microorganism. For Manufacturing Practices (GMPs) and Hazard Analysis example, psychrotrophs such as Listeria and Critical Control Point (HACCP) will help prevent monocytogenes grow at refrigeration temperature biological hazards in your facility. (4°C or 39°F), while thermotrophs can grow at higher temperatures (45°C or 113°F). GMPs ensure hazards associated with personnel and environment are controlled during food production. • The pH of a product is related to the acidity or HACCP controls hazards that may be present in alkalinity of the product. The pH of products affects ingredients and packaging materials and also those the growth of bacteria. Most bacteria grow in a pH that occur during food processing, packaging and range between 5 and 9. storage. • The Water Activity (aw) refers to the water available in the product. The more water available, Processing strategies to control biological hazards: the better bacteria will grow. Table 1 shows the • effective thermal processing used as a kill step (ex: impact of water activity on bacterial spoilage. cooking, pasteurization) • use of appropriate process controls: aw of Bacterial Examples product Spoilage ––storage temperatures (ex: cooler, freezer) >0.90 spoils easily fresh vegetables, ––processing parameters (ex: temperature and time fresh meat, processed for cooking, water activity during dehydration) meat, milk, fish ––adequate cooling system 0.78-0.90 susceptible to dry cheeses, flour, • effective cleaning and sanitizing procedures (ex: spoilage cakes, beans, cereals SSOPs) <0.78 little bacterial rolled oats, dried • use of food technologies to prevent the growth of spoilage but fruits, caramels, bacteria or other biological hazards: mould may dehydrated foods ––packaging techniques (ex: use of vacuum grow packaging, modified atmosphere packaging) Each of these factors is important for the control of ––preservatives microbial growth. It is the interaction among these ––processing techniques (ex: dehydration) factors that determines the growth or control of micro- organisms.

For information on the Food Safety Program contact the CVO/Food Safety Knowledge Centre. For technical information, call 204-795-7968 or 204-795-8418 in Winnipeg; or e-mail [email protected]. For general information, contact your local GO Centre.

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