Food Safety

What is food poisoning?

Foodborne illness (commonly know as food poisoning) cases happen when people eat food that contains pathogens or toxins. You can’t see, smell or taste them, and between 4°C and 60°C or 40°F and 140°F, they can multiply rapidly to create millions of new bacteria in just a few hours.

raw chicken on a cutting board with vegetables

Eating contaminated food can make you sick. For some people, especially young children, the elderly, pregnant women and people with weakened immune systems, food poisoning can be very dangerous and can lead to long-term health complications and even death. That’s why it’s important to prevent it with safe food handling practices.

Signs and Symptoms

Food poisoning is easily mistaken for other types of illnesses. It is not always easy to tell that your symptoms have been caused by food because you can start feeling sick anywhere from hours to weeks after eating contaminated food.

Food poisoning may cause a variety of symptoms, including:

In serious cases, food poisoning can cause nervous system problems like paralysis, double vision or trouble swallowing or breathing. If severe symptoms or present, or the victim is a young child, elderly, pregnant or already ill, call or visit your doctor right away.

If you have signs or symptoms of food poisoning, contact your doctor.

Back to top

The Illnesses


What is botulism?

Botulism (boch-uh-liz-uhm) is a rare but serious illness caused by bacteria. It’s usually caused by poorly home-canned foods with low acid content (asparagus, green beans, beets, corn) and lightly preserved foods like fermented, salted or smoked fish and meat products. In infants it can be caused by honey and corn syrup. Botulism can be fatal and should be considered a medical emergency.

Symptoms of botulism include :

These are all symptoms of muscle paralysis caused by bacterial toxins. If untreated, these symptoms could progress to paralysis of the neck, arms, respiratory muscles, torso and legs.

Symptoms usually start 12 to 36 hours after eating contaminated food, but they can occur as early as six hours or as late as 10 days.

Find out more


Brucellosis (bru·cel·lo·sis), also known as Undulant Fever, is a rare infectious disease caused by bacteria. People can become infected by consuming contaminated or unpasteurized milk and dairy products.

Symptoms of Brucellosis can vary but they might include :

Symptoms usually appear within 8 weeks of eating contaminated food.

Find out more


Campylobacteriosis (cam·py·lo·bac·teer-ee-o-sis)is the most common kind of food poisoning. It’s caused by bacteria that infect the intestinal tract and sometimes the blood. Usually people get it by eating undercooked meat and meat products or raw, unpasteurized or contaminated milk.

Symptoms of campylobacteriosis include :

Symptoms usually begin two to five days after exposure, but it can also be as little as one day or as long as 10 days. They usually last for three to six days. Some infected people might not have any symptoms but they can pass the disease onto others.

Find out more


Cryptosporidiosis (krip-toh-spo-ri-dee-oh-sus) is caused by microscopic parasites. People can become infected by consuming contaminated water or eating raw or undercooked food that’s been contaminated

Cryptospiridiosis has been associated with camping and travelling. Campers and travellers should be aware if it’s common in the area they will be visiting. Contact a travel medicine clinic to find out.

Symptoms of Cryptosporidiosis include :

Symptoms of cryptosporidiosis usually appear between 1 and 12 days after becoming infected and last for 10 to 14 days, although occasionally they may last longer.Some infected people might not have any symptoms but can still pass the disease onto others. If you think you might have cryptosporidiosis, contact your doctor.

Find out more

E. coli Bacteria

E. coli (ee koh-lahy) are bacteria commonly found in the intestines of humans and animals. There are many different types of E. coli. Some not harmful, but some can cause serious illness. E. coli infections can be spread by many food sources such as undercooked ground beef, unpasteurized apple cider and milk, ham, turkey, roast beef, sandwich meats, raw vegetables, cheese and contaminated water. Once someone has consumed contaminated food or water, the infection can be passed from person to person by hand or mouth contact.

Symptoms of E. coli include :

Find out more


Giardiasis (gee-are-dye-uh-sis) is a diarrheal disease caused by microscopic parasites.

Giardiasis has been associated with camping and travelling. Campers and travellers should be aware if giardiasis is common in the area they will be visiting. For more information, consult a travel medicine clinic to assess personal risk and appropriate preventive measures.

Giardiasis causes a variety symptoms including :

Symptoms usually begin seven to 10 days after exposure, but it can also be as little as three or as long as 25 days. They typically last two to six weeks. If you think you might have giardiasis, contact your doctor.

Find out more


Listeriosis (lis·te·ri·o·sis) is caused by bacteria that are widespread in the environment. It’s found in soil, water, mud, forage and silage. The elderly, newborns, pregnant women and those who have a weakened immune system are most susceptible to developing Listeriosis. Listeriosis is caused by eating food contaminated with Listeria bacteria. Listeria can be found in unpasteurized (raw) dairy products, raw vegetables and uncooked meats. Foods can also be contaminated after processing, such as hot dogs, cold cuts or deli meats.

Symptoms of Listeriosis include :

Find out more


Salmonella (sal-muh-nel-uh) is a bacterium that causes a food-borne infection called Salmonellosis. Salmonellosis is usually caused by eating food contaminated by feces of an infected animal or person or by drinking contaminated water. It can also spread from person-to-person.

Symptoms of salmonellosis include :

Symptoms usually occur within 6 and 72 hours of being infected.

 Find out more


Yersiniosis (yer-sin-ee-o-sis) is a disease caused by bacteria. People usually become infected by eating contaminated food, especially raw or undercooked pork products, by ingesting contaminated water or by consuming unpasteurized milk or milk products. Symptoms vary depending on the age of a person infected.

Symptoms in children include :

In older children and adults, symptoms include :

Find out more

Back to top


Follow these four steps to make sure you’re handling all the food you eat safely and to prevent your family, friends and yourself from getting ill.

1. Clean


2. Separate

3. Cook

4. Chill

Here are some food safety tips that can help keep you and your family prevent food poisoning :

At the store

When you’re grocery shopping, be careful to keep raw meat separate from other products in your shopping cart and bags. Pick out cold food last and always get perishable items into your fridge within 2 hours, especially when it’s warm outside.  If you’re not going home right away, use a cooler with ice and a thermometer to make sure perishable food is kept at safe temperatures of less than 4C.

In the fridge :

Thawing your meat :

Back to top

For More Information

Call ServiceOntario, Infoline at 1-866-532-3161
In Toronto, 416-314-5518
TTY 1-800-387-5559
In Toronto, TTY 416-327-4282
Hours of operation : 8:30am - 5:00pm