1. Food Safety Hazards

2. Objectives Review principles of microbiological growth & survival.
Give examples of chemical, physical, and biological hazards found in food.
Discuss control measures used at retail to prevent bacterial, viral, and protozoan foodborne illness.

3. Hazard
A biological, chemical, or physical property that may cause an unacceptable consumer health risk.

4. Chemical Hazards
Natural - mycotoxins, scombroid and ciguatera toxin, toxic mushrooms, shellfish toxins, allergens
Added - medicines, food or color additives, pesticides, cleaners, sanitizers

5. Naturally Occurring Chemical Hazards
Finfish (e.g., tuna, mahi mahi, grouper, snapper) often implicated
Can cause neurological, cardiovascular, and gastrointestinal symptoms
Examples:
Scombrotoxin
Ciguatera
Please see pg. 67, Operators Guide – Seafood References

6. Control of Chemical Hazards
Natural occurring chemicals
Approved sources of food
Added chemicals- Standard Operating Procedures (SOPs)
Proper storage of chemicals
Labeling of chemicals
Restriction of chemicals in facility

7. Physical Hazards Poor handling procedures in the food flow
Examples: plastic, bones, wood, glass, metal fragments,

8. Control of Physical Hazards
Standard Operating Procedures
Buyer specifications
Equipment- light shields
Facility- maintenance of physical surroundings
Buyer specifications- no bones in fish
Equipment-
Facility- floors, walls, ceilings maintained to prevent paint, etc from getting in food

9. Biological Hazards
Include bacterial, viral, and parasitic organisms

10. Bacteria, Viruses, and Parasites – What’s the Difference?
Bacteria grow in food and in the body
Bacterial Infection vs. Intoxication
Viruses and parasites cannot grow in food, only in the body.

11. Key Factors that affect Bacterial Growth
Food – Nutrients
Acidity
Time
Temperature
Oxygen
Moisture

12. Factors for Growth: Food - Nutrients
Protein
Carbohydrates (sugars)
Fats
Vitamins
Minerals

13. Factors for Growth: Acidity of a Product - pH
pH is the measure of the H+ concentration of a product.
pH scale is 0-14; below 7 is acidic, 7 is neutral, above 7 is basic
Most bacteria prefer to grow in a relatively neutral environment.
What common foods and ingredients may be used to lower the pH of the final product?
Below what pH are bacteria unable to grow (but may survive)?
pH 4.6

14. Approximate pH Values of Some Foods

15. Factors for Growth: Moisture – Water Activity
Amount of water available for bacteria to “live” or “grow”
Generally, the lower the water activity, the lower the growth rate of organisms
Bacteria can’t grow (but may survive) in an environment with aw of 0.85 or less

16. Water Activity of Some Foods
0.85

17. Factors for Growth: Time and Temperature

18. Time and Temperature
Key control measures of biological hazards in FDA Food Code
Used to control almost all potential biological hazards except viruses
Easily monitored and food quality minimally affected

19. Time and Temperature (2001 Food Code)
Danger Zone
41F- 140F
Cooking raw animal foods
145F 15 sec- fish, meat, game, eggs
155F 15 sec-pork, ratites, injected and comminuted meats, pooled eggs
165F 15 sec- poultry, stuffed fish, meat, pasta, poultry

20. Time and Temperature (2001 Food Code)
Cooling of PHF (potentially hazardous food)
From 140F to 70F within 2 hours and
From 70F to 41F, or below within 4 hours

21. Time and Temperature (2001 Food Code)
Hot holding of PHF
140F
Cold holding of PHF
41F
Time as a Public Health Control
4 hours

22. Potentially Hazardous Food (PHF) 2001 Definition
A food that requires temperature control because it
supports the . . .
Rapid & Progressive Growth of pathogens;
Growth & Toxin Production of C. botulinum; and/or
Growth of S. Enteritidis in Shell Eggs.
INCLUDED: Animal Foods, Heat Treated Plant Food, Raw Seed Sprouts, Cut Melons, Garlic in Oil
Refer to Definition of Potentially Hazardous Food in Chapter 1. (Page 12)
Rapid Growth - multiplication in Hours Vs. Days
Progressive Growth - Exponential growth leading to numbers that may cause illness.
C. bot toxin is of concern. Consider the outbreaks relating to baked potatoes back in the 70’s. Garlic in oil is also a concern with regards to growth and toxin production of C. bot.

23. Food that is NOT a PHF (based on 2001 Food Code)
aw of 0.85 or less
pH of 4.6 or less
Hermetically sealed container
Lab evidence
A food that can cause illness but does not support growth of pathogens (contaminated or otherwise adulterated food)
An air-cooled hard-boiled egg with shell intact
Water activity and pH have long been determining factors in decision making of whether or not a food is potentially hazardous.
Food in hermetically sealed containers that have not been opened is not PHF.
Laboratory evidence may be used to determine if a food will support the growth of pathogens in a food. Example, some pies have been deemed non-PHF although the water activity and pH are above the critical limits.
An example of a food that can cause illness but does not support growth of pathogens is apple juice. E. coli O157:H7 has been implicated in outbreaks involving low pH apple juice. The organism may be present in the apple juice, but it will not grow at such a low pH. pH of apple juice may be (See Definition (61)(c)(vi), page 12.)

24. PHF (TCS Food) does not include . . .
Air-cooled, hard boiled egg – shell intact
Shell eggs treated to destroy all salmonellae (pasteurized shell eggs)
A food that does not support the growth of pathogenic microorganisms even though they may be present
Some foods that are refrigerated for quality, not safety

25. PHF/TCS Food or not? Exercise
1) Swiss cheese
2) Raw seed sprouts
3) Pasteurized skim milk
4) Opened canned green beans
5) Cut watermelon
6) Garlic-in-oil mixture
7) Unpasteurized orange juice
8) Pre-washed lettuce salad
9) Sour cream
10) Island Dressing
11) Butter
12) Margarine
13) Pumpkin pie
Instruct student to take a few minutes to determine if foods are PHF or not. They may refer back to slides #16 and #18 (Aw and pH tables)

26. PHF/TCS Food or not? Exercise answers
1) Swiss cheese- yes
2) Raw seed sprouts-yes
3) Pasteurized skim milk-yes
4) Opened canned green beans-yes
5) Cut watermelon-yes
6) Garlic-in-oil mixture-yes
7) Unpasteurized orange juice-no
8) Pre-washed lettuce salad-no
9) Sour cream-no, if commercial
10) Island Dressing-no, if commercial
11) Butter-yes
12) Margarine-no
13) Pumpkin pie-yes

27. Vegetative Bacteria
Found on many raw animal foods (meat, fish, eggs, milk), as well as processed foods
Examples
Salmonella
Campylobacter jejuni
E. coli O157:H7
Listeria monocytogenes
Vibrio spp.
Control Measures
Cooking
No Bare Hand Contact with RTE
Handwashing
Employee Health
Temperature Control
Tell student to see HACCP Operator’s Guide pages for a complete list of pathogens and associated foods
Salmonella and Campylobacter in raw poultry
Salmonella enteriditis in raw eggs
E. Coli 0157:H7 in raw ground beef
Listeria monocytogenes in ready to eat foods such as deli meats

28. Bacterial Spore-Formers
Spore – survival mechanism for certain bacteria
Heat resistance exceeds normal cooking temperatures
Spore-forming organisms
C. perfringens
C. botulinum
B. cereus
Control Measures
Proper Cooling
Hot and Cold Holding
Tell students to see page 65in HACCP Regulators Guide for a complete list of pathogens and associated foods
C. perf in cooked meat and poultry
C. Botulinum in vacuum packaged, ROP foods
B. Cereus in meat, poultry and starchy foods

29. Staphylococcus aureus
High numbers of cells produce heat stable toxin in RTE food
Caused by bare hand contact with RTE food and temperature abuse
Poor competitor on raw foods
Reheating will not destroy toxin

30. Foodborne Viruses Hepatitis A – 83,000 cases (5%)*
Noroviruses (formally known as Norwalk-like viruses) – 23M cases (40%)*
*percent foodborne
Mead et al., 1999

31. Foodborne Viruses Shed primarily in human feces
Viruses in food is evidence of fecal contamination
Key is to prevent fecal contamination of food

32. Viruses and Cooking Viruses display variable resistance to heat
No bare hand contact with RTE, proper handwashing, and implementation of effective employee health policies are important control measures

33. Fungi Yeasts Molds Mushrooms
Yeasts are generally not pathogenic but can cause food spoilage.
Fungi problems are more commonly found outside the body – dermatophytoses (athlete’s foot) and zoonotic fungi (ringworm)
An important exception is the yeast causing candidiasis, a serious mouth infection
Most molds are not pathogenic, some produce mycotoxins such as alflatoxin

34. Parasites Live within another organism or host
Trichinella spiralis
Entamoeba histoytica
Giardia lambia
Cryptosporidium spp.
Control parasites through proper cooking and using safe water supplies
T. spiralis- roundworm in pork and other meats
E. histolytica- amoeba in contaminated water- Montezuma’s revenge, traveler’s diarrhea
G. lambia- protozoan transmitted form infrected food workers and contaminated water
Control parasites via cooking, safe water supplies

35. The Problem – Foodborne Illness
Estimated 76 million illnesses
325,000 hospitalizations annually; hospital stays estimated at more than $3 billion
and 5,000 deaths!
Why are we concerned about pathogens in food? This is why
Mead et al., Emerg. Infect. Dis. 5:

36. Percentage of Foodborne Illness Attributable to Various Pathogens
Mead et al., 1999

37. Salmonella Hepatitis A
Infection –
Salmonella Hepatitis A
Campylobacter Norovirus
Listeria
Trichinella
Anisakis
Shigella
Intoxication-
C. botulinum
B. cereus (Emetic)
Staphylococcus
Other-
Scombrotoxin
Ciguatoxin
Toxin-Mediated Infections
C. perfringens
B. cereus (Diarrheal)
E. Coli 0157:H7
Summary slide of pathogens of concern