What You Need to Know When the Power Goes Out Unexpectedly

CDC offers these tips to help you prepare for and cope with sudden loss of power.

Food Safety

If the power is out for less than 2 hours, then the food in your refrigerator and freezer will be safe to consume. While the power is out, keep the refrigerator and freezer doors closed as much as possible to keep food cold for longer.

If the power is out for longer than 2 hours, follow the guidelines below:

• For the Freezer section: A freezer that is half full will hold food safely for up to 24 hours. A full freezer will hold food safely for 48 hours. Do not open the freezer door if you can avoid it.
• For the Refrigerated section: Pack milk, other dairy products, meat, fish, eggs, gravy, and spoilable leftovers into a cooler surrounded by ice. Inexpensive Styrofoam coolers are fine for this purpose.
• Use a digital quick-response thermometer to check the temperature of your food right before you cook or eat it. Throw away any food that has a temperature of more than 40 degrees Fahrenheit.

The following resources provide additional information on preparing for emergencies and determining if your food is safe after a power outage: 

• Food Safety After a Power Outage - American Red Cross (Provides tips on safely storing your food and a chart to help you determine if your food is still safe.)
• Food Safety Office - CDC (Comprehensive food safety information.)

Safe Drinking Water

When power goes out, water purification systems may not be functioning fully. Safe water for drinking, cooking, and personal hygiene includes bottled, boiled, or treated water. Your state or local health department can make specific recommendations for boiling or treating water in your area. Here are some general rules concerning water for drinking, cooking, and personal hygiene. Remember:

• Do not use contaminated water to wash dishes, brush your teeth, wash and prepare food, wash your hands, make ice, or make baby formula. If possible, use baby formula that does not need to have water added. You can use an alcohol-based hand sanitizer to wash your hands.
• If you use bottled water, be sure it came from a safe source. If you do not know that the water came from a safe source, you should boil or treat it before you use it. Use only bottled, boiled, or treated water until your supply is tested and found safe.
• Boiling water, when practical, is the preferred way to kill harmful bacteria and parasites. Bringing water to a rolling boil for 1 minute will kill most organisms.
• When boiling water is not practical, you can treat water with chlorine tablets, iodine tablets, or unscented household chlorine bleach (5.25% sodium hypochlorite):
• • If you use chlorine tablets or iodine tablets, follow the directions that come with the tablets.
  • If you use household chlorine bleach, add 1/8 teaspoon (~0.75 mL) of bleach per gallon of water if the water is clear. For cloudy water, add 1/4 teaspoon (~1.50 mL) of bleach per gallon. Mix the solution thoroughly and let it stand for about 30 minutes before using it.
  • Note: Treating water with chlorine tablets, iodine tablets, or liquid bleach will not kill
    parasitic organisms.  

Use a bleach solution to rinse water containers before reusing them. Use water storage tanks and other types of containers with caution. For example, fire truck storage tanks and previously used cans or bottles may be contaminated with microbes or chemicals. Do not rely on untested devices for decontaminating water.

First Aid for Electrical Shock

If you believe someone has been electrocuted take the following steps:

1.  Look first. Don’t touch. The person may still be in contact with the electrical source. Touching the person may pass the current through you.  
2.  Call or have someone else call 911 or emergency medical help.    
3. Turn off the source of electricity if possible. If not, move the source away from you and the affected person using a nonconducting object made of cardboard, plastic or wood.     
4. Once the person is free of the source of electricity, check the person's breathing and pulse. If either has stopped or seems dangerously slow or shallow, begin cardiopulmonary resuscitation (CPR) immediately.    
5.  If the person is faint or pale or shows other signs of shock, lay the person down with the head slightly lower than the trunk of his or her body and the legs elevated.   
6. Don’t touch burns, break blisters, or remove burned clothing. Electrical shock may cause burns inside the body, so be sure the person is taken to a doctor.

Do not try to help someone else from the car while you are standing on the ground.  

Avoid Carbon Monoxide

For important information about the risk of carbon monoxide poisoning during a power outage:

• CDC Emergency Preparedness and Response - Carbon Monoxide Poisoning After a Disaster
• CDC Caron Monoxide Poisoning Fact Sheet

As power returns after an outage, people at work may be at risk of electrical or traumatic injuries as power lines are reenergized and equipment is reactivated. CDC recommends that employers and employees be aware of those risks and take protective steps if they are in contact with or in proximity to power lines, electrical components, and the moving parts of heavy machinery. More information on electrical safety is available “Worker Safety in Power Outages”

CDC recommends that people make an emergency plan that includes a disaster supply kit. This kit should include enough water, dried and canned food, and emergency supplies (flashlights, batteries, first-aid supplies, prescription medicines, and a digital thermometer) to last at least 3 days. Use battery-powered flashlights and lanterns, rather than candles, gas lanterns, or torches (to minimize the risk of fire). You can find more information on emergency plans and supply kits at Ready America.

Impact of Power Outage on Vaccine Storage

This outage has significant implications for vaccine storage. The following information from CDC’s National Immunization Program should provide some guidance regarding vaccine storage issues.