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It is always great until something blows something up in the office microwave or gets burnt, then it’s the safety lesson

Yes it’s always snack or lunch time until the safety person shows up with incident report form and needs to apply first aid in some case. Why you might ask, well maybe no one ever covered the safety risks! And since you have to do the incident report can I have your butter curried chicken you’ll be busy learning and writing?

·        Rule one on microwave at work READ THE INSTRUCTIONS

·        Rule two always wear and have OVEN MITTS in place before taking stuff out after heating!!!!!!!

·        Rule three if you MAKE A MESS CLEAN IT UP!

And the other CRITICAL 3

·        Do not use aluminum foil or any metal containers, metal utensils, metal objects, or objects with metal or foil trim in the oven. They can cause arcing, damaging the oven and creating a fire or burn hazard.

·        Do not heat objects that are sealed as they may explode, damaging the oven and blowing off the door.

·        Never heat flammable or combustible liquid in the oven. A fire and/or explosion may result.

SAFE TO USE:

·        Any utensil labeled for microwave use.

·        Heatproof glass (such as Pyrex, Anchor Hocking, etc.).

·        Glass-ceramic (such as Corning Ware).

·        Oven cooking bags.

·        Baskets (straw and wood) for quick warm-ups of rolls or bread. Line the basket with napkins to absorb moisture from food.

·        Most paper plates, towels, napkins and bags. For optimal safety use white, unprinted materials.

·        Wax paper, parchment paper, heavy plastic wrap. Do not allow plastic wrap to touch food; vent it to allow a steam escape.

·        Heat-susceptor packaging.

NOT SAFE TO USE:

·        Cold storage containers: margarine tubs, cottage cheese and yogurt cartons, etc. These materials are not approved for cooking and chemicals can migrate into food.

·        Brown paper bags and newspapers.

·        Metal pans.

·        Foam-insulated cups, bowls, plates or trays.

·        China with metallic paint or trim.

·        Chinese “take-out” containers with metal handles.

·        Metal “twist ties” on package wrapping.

·        Food completely wrapped in aluminum foil.

·        Food cooked in any container or packaging that has warped or melted during heating.

In a microwave oven, food is cooked by exposing it to microwave radiation. Microwaves are a form of radiofrequency (RF) electromagnetic energy. When this energy comes in contact with food, the absorbed energy causes the water molecules in the food to rotate. This movement causes friction between the molecules and produces a rapid rise in temperature. Microwave energy generated by the magnetron is transferred to the oven cavity through a waveguide section (2450 MHz (megahertz) for most conventional ovens). A mode stirrer spreads the microwave energy more or less evenly throughout the oven.

What are power levels?

On high power, the food is subjected to the highest amount of microwave energy because the magnetron produces microwaves at full capacity. To produce a power level less than high (100%), the magnetron cycles off and on. For example, medium power (50%) means that the oven produces microwaves 50% of the time and is off 50% of the time.

“Time-to-Boil Test” 

Measure a cup of water in a 2-cup glass measure. Add ice cubes; stir until water is ice cold. Discard ice cubes and pour out any water more than 1 cup. Set the microwave on high 4 minutes, but watch the water through the window to see when it boils.

·        If water boils in less than 2 minutes, it is a very high wattage oven 1000 watts or more.

·        If water boils in 2½ minutes, it is a high wattage oven about 800 watts or more.

·        If water boils in 3 minutes, it is an average wattage oven 650 to 700 watts or more.

·        If water boils in more than 3 minutes or not by 4 minutes, it is a slow oven 300 to 500 watts.

Foods best to cook on high power are basically tender foods and those with a high moisture content such as ground beef, poultry, vegetables and fruits. Eggs, cheese and solid meat can toughen when microwaved on high. They are best cooked on reduced power. Large cuts of meat should be cooked on medium power (50%) for longer periods. This allows heat to reach the center without overcooking outer areas.

What is “arcing”?

Arcing (pronounced “AR-king”) is sparks inside the microwave oven caused when microwaves react to gold paint on dishes, twist ties and other metallic materials. Some foods such as raw carrots and hot dogs can cause arcing while being microwaved. In hot dogs, this can be due to the uneven mixing of salts and additives. In carrots, it can be due to the minerals in the soil in which they were grown. Whatever the cause, turn off the oven immediately to end the sparks. Prolonged arcing can damage the oven and/or the utensil. If caught at once, arcing should not damage the oven. Remove the offending utensil or food from the oven and either substitute a microwave-safe utensil or cook the food by other methods.

What is “erupting”?

Erupting, or violent boiling over, can occur when a liquid (primarily water) heated in a microwave oven becomes hotter than its conventional 212 °F boiling temperature (super-heated). The liquid boils over when instant coffee, tea or gelatin is added to the superheated water. In extremely rare instances, all that is needed to initiate boiling of a superheated liquid is motion. Thus, a superheated cup of water could theoretically erupt violently when it is removed from a microwave oven.

Superheating usually occurs when microwaving water in a very clean vessel — usually just taken from a dishwasher — or when microwaving room temperature water. It also happens because liquids heat with internal “hot spots” so that a temperature higher than 212 °F (the boiling point of water) builds up an inch or two below the surface.

Thus, even though it is extremely unlikely for an eruption to occur in a microwave oven, several precautions can be taken to lessen the potential for a problem:

·        Use a vessel with sloping walls, such as a measuring cup.

·        Leave a microwavable spoon in the vessel while heating.

·        Stir occasionally while heating.

·        Add a pinch of instant coffee, a tea bag, or gelatin at the beginning or halfway through heating.

Do microwaves cook food from the inside out?

No. Microwaves penetrate the food to a depth of 1 to 1½ inches. In thicker pieces of food, the microwaves don’t reach the center. That area would cook by conduction of heat from the outer areas of the food into the middle.

In a microwave oven, the air in the oven is at room temperature so the temperature of the food surface is cooler than food in a conventional oven where the food is heated by hot air. Therefore, food cooked in a microwave oven doesn’t normally become brown and crispy.

Microwave radiation is measured as ‘power density’ in units of milliwatts per square centimetre (mW/cm2) which is essentially the rate of energy present in one square centimetre. Special equipment is needed to detect and measure the leakage. http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/radio_guide-lignes_direct/index-eng.php

Have a heart!

Most models today are not affected by being near a microwave oven, as long as the leakage is within the limits specified by Health Canada’s regulation. Anyone with a pacemaker who gets dizzy or experiences discomfort around a microwave oven should move away from the oven immediately and consult a health care professional.”

Do microwaves cook food safely?

Bacteria will be destroyed during microwave cooking just as in other types of ovens, so food is safe cooked in a microwave oven. However the food can cook less evenly than in a conventional oven. Microwave cooking can be uneven just as with frying and grilling.

For that reason, it is important to use a food thermometer and test food in several places to be sure it has reached the recommended temperature to destroy bacteria and other pathogens that could cause foodborne illness.

To promote uniform cooking, arrange food items evenly in a covered dish and add some liquid if needed. Where possible, debone large pieces of meat; bone can shield meat from thorough cooking.

Cover the dish with a lid or plastic wrap. Allow enough space between the food and the top of the dish so that plastic wrap does not touch the food. Loosen or vent the lid or wrap to allow steam to vent. The moist heat that is created will help destroy harmful bacteria and ensure uniform cooking. Cooking bags also provide safe, even cooking.

Stir, rotate, or turn foods upside down (where possible) midway through the microwaving time to even the cooking and eliminate cold spots where harmful bacteria can survive. Even if the microwave oven has a turntable, it’s still helpful to stir and turn food top to bottom.

Follow cooking instructions on product label (or recipe instructions). If a range of time is given, start with the fewest minutes recommended. Add cooking time if necessary to reach a safe internal temperature.

Observe the “standing time.” Cooking continues and is completed during standing time. Most importantly, follow the manufacturer’s instructions. Microwave Ovens and Food Safety

The microwave oven is one of the great inventions of the 20th century; over 90% of homes in America have at least one. Microwave ovens can play an important role at mealtime, but special care must be taken when cooking or reheating meat, poultry, fish, and eggs to make sure they are prepared safely. Microwave ovens can cook unevenly and leave “cold spots” where harmful bacteria can survive. For this reason, it is important to use a food thermometer and test food in several places to be sure it has reached the recommended safe temperature to destroy bacteria and other pathogens that could cause foodborne illness.

How do microwaves cook food?

The magnetron inside the oven converts ordinary electric power from a wall socket into very short radio waves (around 4 inches from crest to crest). They are transmitted by the oven’s magnetron at a frequency of about 2450 Megahertz. At that frequency, power is readily absorbed by water, fats and sugars, resulting in very fast vibration and high temperatures that cook the food.

What are power levels?

On high power, the food is subjected to the highest amount of microwave energy because the magnetron produces microwaves at full capacity. To produce a power level less than high (100%), the magnetron cycles off and on. For example, medium power (50%) means that the oven produces microwaves 50% of the time and is off 50% of the time.

Foods best to cook on high power are basically tender foods and those with a high moisture content such as ground beef, poultry, vegetables and fruits. Eggs, cheese and solid meat can toughen when microwaved on high. They are best cooked on reduced power. Large cuts of meat should be cooked on medium power (50%) for longer periods. This allows heat to reach the center without overcooking outer areas.

Do microwaves cook food from the inside out?

No. Microwaves penetrate the food to a depth of 1 to 1½ inches. In thicker pieces of food, the microwaves don’t reach the center. That area would cook by conduction of heat from the outer areas of the food into the middle.

In a microwave oven, the air in the oven is at room temperature so the temperature of the food surface is cooler than food in a conventional oven where the food is heated by hot air. Therefore, food cooked in a microwave oven doesn’t normally become brown and crispy.

Do microwaves cook food safely?

Bacteria will be destroyed during microwave cooking just as in other types of ovens, so food is safe cooked in a microwave oven. However the food can cook less evenly than in a conventional oven. Microwave cooking can be uneven just as with frying and grilling.

For that reason, it is important to use a food thermometer and test food in several places to be sure it has reached the recommended temperature to destroy bacteria and other pathogens that could cause foodborne illness.

To promote uniform cooking, arrange food items evenly in a covered dish and add some liquid if needed. Where possible, debone large pieces of meat; bone can shield meat from thorough cooking.

Cover the dish with a lid or plastic wrap. Allow enough space between the food and the top of the dish so that plastic wrap does not touch the food. Loosen or vent the lid or wrap to allow steam to vent. The moist heat that is created will help destroy harmful bacteria and ensure uniform cooking. Cooking bags also provide safe, even cooking.

Stir, rotate, or turn foods upside down (where possible) midway through the microwaving time to even the cooking and eliminate cold spots where harmful bacteria can survive. Even if the microwave oven has a turntable, it’s still helpful to stir and turn food top to bottom.

Follow cooking instructions on product label (or recipe instructions). If a range of time is given, start with the fewest minutes recommended. Add cooking time if necessary to reach a safe internal temperature.

Observe the “standing time.” Cooking continues and is completed during standing time. Most importantly, follow the manufacturer’s instructions.

What is “standing time”?

Microwaves cause water, fat, and sugar molecules to vibrate 2.5 million times per second, producing heat. After the oven is off or food is removed from the oven, the molecules continue to generate heat as they come to a standstill. This additional cooking after microwaving stops is called “carryover cooking time,” “resting time,” or “standing time.” It occurs for a longer time in dense foods such as a whole turkey or beef roast than in less-dense foods like breads, small vegetables and fruits. During this time, the temperature of a food can increase several degrees. For that reason, directions may advise to let a food “rest” for a few minutes after turning off the oven or removing food from the oven.

Use a food thermometer or the oven’s temperature probe to verify the food has reached a safe internal temperature. Unless the food thermometer is labeled safe for microwave cooking, do not leave the thermometer in the food during microwaving. Instead, use an instant read food thermometer to test the temperature of the food after removing it from the microwave oven.

Safety tips for the operation of microwave ovens:

  • Follow the manufacturer’s instructions for operating procedures and safety precautions. Any misuse of the oven may result in personal injury.
  • As mentioned above, persons with modern pacemakers should not experience difficulty when near a microwave that is in good working condition. However, if you have concerns or notice symptoms (e.g., dizziness or discomfort), move away from the microwave immediately and consult with your doctor.
  • Check to see that door seal and inside surfaces of door and oven cavity are clean after each use.
  • Repair or replace any microwave that is not in good working condition.
  • Repairs should only be done by a qualified service person.
  • Do not use the microwave if the door does not close (e.g., is bent, warped or damaged in any way).
  • Do not disable or by-pass any safety locks.
  • Do not insert an object through an opening or around the door seal.

Safety tips for the maintenance of microwave ovens include:

  • Take special care to ensure that no damage occurs to the part of the oven making contact with the door or door seals.
  • Repairs should only be done by a qualified service person.
  • Do not by-pass the door interlocks.

Safety tips for the repair and testing of microwave ovens and their components include:

  • Only qualified service personnel should attempt repairs and/or testing of microwave ovens and their components.
  • Service personnel should be aware of any risk associated with exposure to microwave energy when performing tests or repairs.

Ensure that the adjustment of applied voltages, replacement of the microwave power generating component, dismantling of oven components, and refitting of waveguides are done only by persons who have been specifically trained for such tasks. Do not test a microwave power generating component without an appropriate load connected to its output. The power generated must never be allowed to radiate freely into occupied areas.

Microwave ovens are used every day, both at home and in the workplace. When used properly, the microwave is safe and convenient for heating a variety of foods in a short time. When you become complacent about microwave safety, however, your appliance can cause painful burns and become a potential fire hazard.

The following tips will help make the use of your microwave oven a safe method of food preparation.

  • Before using a new microwave oven, always read the manufacturers operating procedures and safety precautions first.
  • To minimize risk of fire, never attempt to heat articles that are not approved for use in microwave ovens.
  • Remove food from packaging before defrosting in a microwave oven. Do not use plastic storage containers, foam trays and plastic wraps in microwave ovens because they are not heat stable at high temperatures. Melting or warping can occur which may cause harmful chemicals to migrate into the food.
  • Never use recycled paper products in microwave ovens unless they are specifically approved for microwave use. Some recycled products including paper towels and even waxed paper may contain minute metal flecks. When a microwave oven is operating, the interaction between microwaves and the metal can cause sparks and even flames.
  • Do not leave a microwave oven unattended when microwaving popcorn, since the heat buildup can cause fires. Heat the popcorn according to the written instructions, but begin with the minimum time specified because some microwaves can scorch popcorn in as little as two minutes.
  • If you have a fire in your microwave oven, turn it off immediately. This will stop the fan so it won’t feed oxygen to the flames. Then simply wait until the fire suffocates. Never open the oven door until you are absolutely certain that the fire is out. If in doubt, call the fire department.
  • Use only microwave-safe utensils. The instructions that come with each microwave oven specify what kinds of containers are safe to use and how to test the suitability of materials before use.
  • Always use oven mitts to remove items from the microwave oven after cooking. Be careful when removing a wrapping or covering from a hot item. Hot steam escaping from the container, as the covering is lifted, can cause painful burns.
  • Be careful when heating liquids in the microwave oven. Since the containers may only feel warm, rather than hot, they are sometimes handled with less caution. This can easily result in the splashing or spilling of a scalding liquid.
  • Before allowing children to operate a microwave oven, make sure that they are instructed in the proper use, and that they are tall enough to reach the oven and handle foods safely. Over 500f those burned using microwave ovens are under 5 years of age.

Microwave Oven Cooking Instructions · Use the microwave only for food or beverages, or other standardized uses. · Do not use metal edged bowls, metal plates or cups, tin foil, or metal twist ties in the oven. The metal can spark, damage the unit, and lead to a fire. Use only microwave safe materials. · Is it safe to microwave food only until partially done?

Never partially cook food and store it for later use because any bacteria present wouldn’t have been destroyed. When partially cooking food in the microwave oven to finish cooking on the grill or in a conventional oven, it is important to transfer the microwaved food to the other heat source immediately.

Read the cooking instructions on the package. · Puncture cooking pouches and foods that have tight skins to release steam as they cook. · Never use a brown paper bag for popping popcorn. It can catch fire.

That is the best way to thaw frozen food in a microwave oven?

Remove food from its packaging before defrosting. Do not use foam trays and plastic wraps because they are not heat stable at high temperatures. Melting or warping from the heat of the food may cause harmful chemicals to migrate into it.

Select the “defrost” setting or 30% power. During microwave defrosting, rotate and turn food upside down where possible. For individual pieces such as chicken parts, break them apart when possible, rotate and turn upside down several times during defrosting. When thawing ground meats, scrape the thawed portion off as it softens; remove it from the oven. Continue to microwave defrost the remaining portion.

How do you safely reheat cooked food in a microwave oven?

·        Cover foods with a lid or a microwave-safe plastic wrap to hold in moisture and provide safe, even heating. Turn back a corner for the steam to vent.

·        Heat ready-to-eat foods such as hot dogs, luncheon meats, fully cooked ham, and leftovers until steaming hot.

·        After reheating foods in the microwave oven, allow standing time. Then, use a clean food thermometer to check that food has reached 165 °F.

Microwave Oven Cleaning Instructions · Clean the door and oven cavity with water and mild detergent. · Do not use abrasives such as scouring pads.

P bar Y Safety Consultants
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