Health Canada is again warning consumers about garlic-in-oil, which can cause serious health problems if not stored properly.

If homemade garlic-in-oil is stored at room temperature, or if it is kept in the fridge too long, botulism spores could grow.

Garlic-in-oil is a mixture of oil and garlic with the garlic either whole, chopped, or minced. If it is refrigerated on a continuous basis and used within a week it is safe.

Clostridium botulinum are widespread and are usually not a problem because they cannot grow if exposed to oxygen according to Health Canada.

The problem occurs when there is no oxygen present, like with the oil.

There may be no obvious signs that garlic-in-oil is spoiled. It will still look, smell and taste the same.

If you eat garlic-in-oil that is infected with the toxins you can get botulism which is potentially fatal.

Symptoms include dizziness, blurred or double vision, difficulty in swallowing, breathing and speaking and paralysis that gets worse with time.

For more on the warning, go here.