OTTAWA, Nov. 15, 2012 /CNW/ - Health Canada would like to remind
Canadians that raw shellfish - such as oysters, clams, scallops,
mussels and cockles - can carry bacteria, viruses and toxins that can
cause foodborne illness if they are not harvested, stored, handled or
Shellfish is a nutritious food choice. As with all foods, it is
important to store, handle and prepare shellfish appropriately to help
prevent illness. In particular, children, pregnant women, seniors and
people with weakened immune systems are more susceptible to foodborne
illness and should avoid eating raw or undercooked shellfish.
Here are some steps you can take to prevent foodborne illness from
Buy shellfish from reputable sources, and keep them cold (below 4°C). A
retailer selling raw shellfish should be able to show you a shellfish
Refrigerate immediately after purchase. Do not put live shellfish in a
closed container or into fresh water. Cover the shells with a damp
cloth and place on the lowest shelf of the refrigerator. Store shucked
(shell removed) shellfish in a closed container. Raw shellfish can be
kept refrigerated for a few days, depending on their freshness and
quality, and can be stored in the freezer for 2-4 months. Shucked
oysters should be frozen if you do not eat them within two days.
Check the packaging on frozen shellfish. Make sure that the packaging is
not torn or open and that there is minimal frost or ice crystal
formation on the packaging. Too much frost could mean that the
shellfish has been frozen for a long time or has been thawed and
refrozen. Place the frozen shellfish in the freezer immediately after
purchase until you are ready to use it. You should never defrost
shellfish at room temperature. Thaw food in the refrigerator, in cold
water, or in the microwave if you will be cooking it immediately. If
thawing in cold water, replace water every 30 minutes. Food should be
cooked immediately after thawing.
Keep raw shellfish separate from cooked foods and follow good hygiene
practices: wash hands before preparing foods, wash hands after handling
raw shellfish, do not use the same plate or utensils for raw and cooked
shellfish, and wash counters and utensils with soap and warm water
Make sure your shellfish is fresh. Fresh oysters, clams, scallops,
mussels and cockles should have tightly closed shells or they should
close their shells when you tap them.
Shucked oysters (usually sold in tubs) are not meant for raw
It is best to cook oysters, clams, scallops, mussels and cockles to
minimize the chances of foodborne illness. Guidelines for cooking
Boil oysters, clams, scallops, mussels and cockles until the shells
open, and then boil for an additional 3-5 minutes. You should also boil
or simmer shucked shellfish for at least 3 minutes or until the edges
Steam for 4-9 minutes and throw out those that did not open.
Fry shucked shellfish for at least 3 minutes at 190°C (375°F)
Bake shucked shellfish for at least 10 minutes at 230°C (450°F).
If you wish to harvest shellfish yourself, make sure you do so in areas
that are open for harvesting. Chemical contaminants or natural toxins
from marine algae could be present in shellfish any time of the year,
and cooking will NOT destroy these toxins. Contact your nearest
Department of Fisheries and Oceans office listed in the blue pages of
your local telephone directory for information on areas currently open
for shellfish harvesting. You may also want to check with your local or
provincial government about harvesting restrictions or consumption
advice for shellfish not purchased from commercial establishments.
It is estimated that there are approximately 11 million cases of
foodborne illnesses in Canada every year. Many of these illnesses
could be prevented by following proper food handling and preparation
If you have any abnormal symptoms or feel ill after eating shellfish,
consult your physician immediately.
More information about shellfish food safety is available from:
Healthy Canadians - Shellfish Food Safety
Canadian Food Inspection Agency - Marine Toxins in Bivalve Shellfish
Canadian Partnership for Consumer Food Safety Education - Be Food Safe
Également disponible en français
SOURCE: Health Canada
For further information: