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Kitchen Food Safety: Bags, Bottles & Beyond

Alice Henneman, MS, Registered Dietitian & Extension Educator
University of Nebraska Cooperative Extension in Lancaster County
ahenneman1@unl.edu
Joyce Jensen, REHS, Environmental Health Specialist
Lincoln-Lancaster County Health Department logo Lincoln-Lancaster County Health Department
jjensen@ci.lincoln.ne.us

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When we think kitchen food safety, the following seven unsafe practices may not come to mind. They should. Do you avoid them? Please do!

1. Using non-food grade materials

Just because a material looks like a suitable food container doesn't make it safe for food. Four common nonfood grade items we should avoid using include the following.

  • Brown paper bags for cooking. Here's what the U.S. Department of Agriculture (USDA) says about this practice: "Do not use brown paper bags from grocery or other stores for cooking. They are not sanitary, may cause a fire, and can emit toxic fumes. Intense heat may cause a bag to ignite, causing a fire in the oven... . The ink, glue, and recycled materials in paper bags can emit toxic fumes when they are exposed to heat. Instead, use purchased oven cooking bags." <www.fsis.usda.gov/OA/pubs/altroute.htm>
USDA also advises, "These bags may not necessarily be sanitary, particularly since they may be stored under a variety of conditions." <www.fsis.usda.gov/oa/pubs/meatpack.htm>
  • Garbage cans for cooking. Garbage cans weren't developed for cooking. It is especially dangerous cooking in galvanized garbage cans as they contain toxic metals that can leach into food.
  • Film canisters for food storage. If a product isn't sold to hold food, don't use it for this purpose. A commonly used nonfood item is film canisters. Use small food storage containers instead.
  • Plastic trash bags for food storage. The use of plastic trash bags for food storage or cooking is not recommended by USDA "... because they are not food grade plastic and chemicals from them may leach into the food."
    <www.fsis.usda.gov/OA/pubs/meatpack.htm>
2. Reusing one-time-use items

While some items should not be used with foods, others should be used only ONCE, and then for their intended purpose. For example, USDA states: "Plastic wrap, foam meat trays, convenience food dishes, and egg cartons have been approved for a specific use and should be considered one-time-use packaging. Bacteria from foods that these packages once contained may remain on the packaging and thus be able to contaminate foods or even hands if reused." <www.fsis.usda.gov/OA/pubs/meatpack.htm>

Other items that were developed with the intention of single use include these four articles:
  • Single-use plastic water bottles. It is better to buy a reusable water bottle and use that instead of reusing a bottle in which water is sold. The plastic water bottles in which water is sold are intended for single service. They are hard to clean and dry and are not meant for multiple cleanings. They may not hold up under the hot water and cleansing needed to remove lipstick, etc.
  • Disposable plastic utensils, cups and containers. This category includes plastic forks, spoons and knives; plastic cups; and containers from cottage cheese, sour cream, chip dip, margarine, milk, etc. These items are not made of materials designed for repeated use or repeated cleaning with hot soap and water. Cups and containers may have edges that curl over and collect bacteria that cannot be cleaned out. These containers are developed for specific types/temperatures of foods and may not stand up to all foods, such as high acid and/or hot foods.
  • Single-use wooden items. Some wooden food-related items, such as popsicle sticks and shish kabob skewers, are intended for one-time use. If you want to reuse shish kabob sticks, buy the metal ones. Rather than reuse popsicle sticks, purchase one of the containers for making popsicles that comes with reusable handles. Or, use a new purchased popsicle stick every time.
  • Lids with non-cleanable liners. Glass jars can be cleaned and reused; however you must be careful of reusing the lids. Lids with a non-cleanable liner,such as a waxed cardboard liner, should not be re-used.
3. Mis-using materials in the microwave

Microwave your food in safe ways using safe containers. USDA advises:

"Microwave food in packaging materials only if the package directs, and then use only one time. Materials suitable for microwaving include oven bags, wax paper and plastic wrap. Do not let the plastic wrap touch the food, and do not reuse the wrap.

"Foam insulated trays and plastic wraps on fresh meats in grocery stores are not intended by the manufacturer to be heated and may melt when in contact with hot foods, allowing chemical migration into the food. In addition, chemical migration from packaging material to a food does not necessarily require direct contact. Excessive heat applied to a closed container may drive off chemical gases from the container that can contaminate the enclosed food.

"These types of plastic products should not be used in a microwave oven because they are subjected to heat when thawing or reheating. To avoid a chemical migration problem, remove meats from their packaging." <www.fsis.usda.gov/OA/pubs/altroute.htm>

An article on "Plastics and the Microwave" in FDA Consumer magazine states, "... carryout containers from restaurants and margarine tubs should not be used in the microwave, according to the American Plastics Council. Inappropriate containers may melt or warp, which can increase the likelihood of spills and burns. Also, discard containers that hold prepared microwavable meals after you use them because they are meant for one-time use."

The FDA article cautions: "Microwave-safe plastic wrap should be placed loosely over food so that steam can escape, and should not directly touch your food. Some plastic wraps have labels indicating that there should be a one-inch or greater space between the plastic and the food during microwave heating."

"Always read directions," advises FDA, "but generally, microwave-safe plastic wraps, wax paper, cooking bags, parchment paper, and white microwave-safe paper towels are safe to use. Covering food helps protect against contamination, keeps moisture in, and allows food to cook evenly. Never use plastic storage bags, grocery bags, newspapers, or aluminum foil in the microwave."
<www.fda.gov/fdac/features/2002/602_plastic.html>

4. Using mercury thermometers

Get rid of old mercury thermometers, but don't just throw them away. Take them to a household hazardous waste collection site.

Mercury thermometers are identifiable by the silver bulb at the bottom and silver coloring in the temperature indicator area. Thermometers with a red or blue liquid do NOT contain mercury. The danger is if a mercury thermometer breaks, toxic fumes are released and the mercury contaminates the area in which it is spilled. It's very difficult -- and EXPENSIVE -- to effectively clean spilled mercury. Replace these thermometers with non-mercury thermometers.

For more information about choosing and using thermometers, see "Forgotten in the Fridge" at lancaster.unl.edu/food/ftmay04.htm and "Pass the Taste Test ... Use a Thermometer" at lancaster.unl.edu/food/ftfeb04.htm

5. Misusing hard-to-clean items

Today, many families are busy rushing and running. Utensils that once were cleaned thoroughly after each use may get set aside. Cleaning is neglected or delayed. Consider these four items:

  • Whisks. When purchasing a metal whisk, some of the easiest ones to clean are stainless steel whisks with their wires attached to the handle with a watertight seal. They don't rust, and food particles don't get trapped in the handle.

As an aside, a whimsical apron sighted on the Internet identifies the wearer as being involved with "Home Cooked Security" and holding the position of "Director of Whisk Assessment."

  • Pastry and basting brushes. Use food grade pastry and basting brushes rather than paint brushes. Paint brushes may not have been treated to be acceptable for food use and/or their design may not be conducive to thorough cleaning.

Avoid cross contamination when using food brushes. For example, don't baste raw meat and then use the same brush on the cooked meat or another food that will not be cooked. Also, it is a good practice to use a different brush for pastry than the one used for basting meats. Wash brushes in hot soapy water and rinse well after each use or run through the dishwasher if dishwasher-safe.

  • Vegetable brushes. Vegetable brushes are designed for scrubbing hard-surfaced vegetables and fruits, such as melons, cucumbers and acorn squash. Clean them thoroughly after each use. The easiest method is to run them through a dishwasher if they are dishwasher safe. Otherwise, clean them with hot soapy water and rinse with hot water or run through the dishwasher if dishwasher-safe.
  • Sponges. Sponges are hard to keep clean for use on food contact surfaces, such as dishes and countertops. Sponges provide an ideal location for bacteria to grow. Bacteria thrive in the warmth, moisture and food collected on sponges.

Sponges should be cleaned and dried after each use and changed frequently. While the recommendation is sometimes made to heat WET sponges in the microwave, the guidelines are not precise and there is a possibility of fire.

Dishcloths are easier to keep clean than sponges and can be purchased very inexpensively. A clean one can be used every time a person does the dishes or wipes the counter. Launder dishcloths in the washing machine in hot water and dry in a hot dryer. Or, use paper towels. A third possibility is to use a combination of paper towels and dishcloths. Some people find it easier to wipe up small spills and clean small areas with a paper towel and to use a dishcloth for cleaning larger areas.

6. Re-using items that should be laundered

Dishcloths and dish towels should be washed after use. Wet or damp dish towels and cloths are ideal environments for bacterial growth. Allow them to air dry before tossing them into a laundry basket. Have a good supply so it is not necessary to re-use them before laundry day.

7. Using damaged items that can't be cleaned

Cutting boards, whether plastic or wood, should be tossed once they contain deep cuts or grooves that cannot be easily cleaned. Discard damaged wooden and nylon utensils that have cracks or melted surfaces.

Permission to reproduce: You may reproduce these materials for educational purposes but not for sales purposes. You're also welcome to link to "Food Reflections" from your website. Please credit: Food Reflections, University of Nebraska Cooperative Extension (lancaster.unl.edu/food/foodtalk.htm)

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