Last week, Leslie helped you clean out your kitchen for spring. This week, she has a quiz to help you assess just how safe your kitchen is for cooking.

Q: True or False? It's unsafe to heat plastic containers in the microwave.

False - as long as they are labelled "microwave safe". There was a widely circulated email warning about the dangers of microwaving food in plastic containers or plastic wrap. The message warned that can leach chemicals out of the plastic and into the food, especially foods with a high fat content like cheese and meats, causing cancer and reproductive problems.

There is some evidence to suggest that certain plasticizers (additives used to make plastic flexible) called phthalates, can leach out and cause cancer and reproductive problems in animals. But the effect isn't clear in humans. Phthalates are commonly found in soft plastics, like the kind meat is wrapped in, and in take out containers.

To ensure safe use of plastic containers or wrap in the microwave:

  • Do not use plastic containers or wrap unless they are labeled "microwave safe". Packaged foods with instructions for microwave heating in the container and storage containers sold for use in microwave ovens are two examples of safe containers. Plastic containers like margarine tubs, yogurt containers, take out containers, whipped topping bowls, and other one-time use containers are not considered safe.
  • Do not let plastic wraps touch the food when heating. Leave one inch between the food and plastic wrap when heating in the microwave. Do not use thin plastic storage bags, plastic grocery bags or aluminum foil in the microwave.
  •  Remove food from the store wrap before thawing or reheating in the microwave, unless the manufacturer has indicated that it's meant for microwave use.

Q: True or False? Teflon pans cause cancer.

False. There's no evidence that using Teflon coated pans, or any other non-stick cookware, causes cancer.

However, one of the chemicals used to make Teflon and other non-stick coatings, called PFOA (perfluorooctanoic acid), is considered to be "likely carcinogenic" in humans since high doses cause liver, pancreatic and testicular cancer in laboratory animals. The health risks of PFOA relate more to the manufacture of nonstick coatings than the use of the cookware made with it.

There is essentially no PFOA left in the cookware after it's manufactured. However, when Teflon is manufactured, some PFOA is released into the environment. And that's what got DuPont, the major supplier of non stick coatings, into trouble. Residents living around the company's plant in West Virginia discovered PFOA in their drinking water. In 2006, the chemical industry voluntarily agreed to reduce and eventually eliminate the release of PFOA into the environment and to reduce and eliminate the use of PFOA content of products.

However, nonstick pans can be risky of they're heated to temperatures greater than 350 C. If you leave an empty nonstick pan on a burner it can get too hot and reach a temperature where toxic fumes re released that cause "polymer fever", a flu-like condition in humans. As long as you have food or liquid in the pan, there's really no risk of overheating the nonstick coating even if you set the burner on high. But it's best to use low or medium heat for nonstick cookware. Do not use nonstick cookware from broiling, which uses higher temperatures. Temperatures used for boiling, baking and frying are safe.

Q: True or False? Raw cookie dough is safe to eat.

False. Cookie dough might seem safe to eat since it doesn't contain raw meat. But if you add eggs to your recipe, you run the risk of salmonella food poisoning. The inside of an egg was once considered almost sterile. But, over recent years, the bacterium Salmonella enteritidis has been found inside a small number of eggs. The likelihood that an egg might contain salmonella is extremely small, but it's still best to play it safe and wait to sample cookies once they're baked. Cooking eggs, or products that contain eggs, to a temperature of at least 71 C kills the bacteria; refrigeration does not.

Q: True or False? Eating microwave popcorn causes health problems.

False. There are two concerns you might have heard about microwave popcorn. The first surfaced in 2004, when exposure to vapors from butter flavouring in microwave popcorn was linked to a rare lung disease in factory workers who made the flavourings. The U.S. National Institute for Occupational Health and Safety linked a chemical used to make the artificial butter, called diacetyl, to the illness. Scientists believe the chemical becomes dangerous when heated and inhaled over an extended period of time. Health officials insist that people who eat use microwave popcorn and eat it at home are not in danger.

Then in 2005, the U.S. FDA found that PFOA, a chemical formed as an impurity in the manufacture of microwave popcorn bags, migrates from the bag into the oil during heating. Later, the FDA declared exposure negligible and not a health hazard.

Bottom line, microwave popcorn is safe to eat however, if the though of eating trace amounts of PFOA concerns you, use an air popper or heat your kernels in a covered pot on the stove.

Q: True or False? You should cool hot leftovers on the countertop before storing in the fridge.

False. When you refrigerate leftovers, it should be cool enough to prevent it from fostering the growth of bacteria that cause food poisoning and warming the food around it to an unsafe temperature. But letting hot food sit on the counter to cool at room temperature make sit a potential breeding ground for bacteria. Disease-causing bacteria multiply rapidly in the danger zone, a temperature range of 4 C and 60 C, leading to food contamination.

You need to refrigerate or freeze leftovers within two hours. Too cool food, put containers of hot food into cold water or ice baths to drop their temperature. Or divide hot food into smaller, shallow containers to ensure safe, rapid cooling. The faster food cools down, the safer it is. And don't overstuff the fridge. Cold air needs to circulate above and beneath food to keep it properly chilled.