How can severe weather conditions affect the viability of biological products? Extreme weather can result in an interrupted cold chain. Weather conditions can play a major role in the effectiveness of sensitive and expensive medicines and vaccines. Conditions such as power outages or flooding during a hurricane can affect the cold chain delivery of products to the end-users, the patients.

It is imperative that these biologics remain in perfect condition to save lives. The lives of patients cannot be put at risk when medicines are rendered toxic due to the severe weather conditions. Short term power failures do not necessarily result in the spoilage of stored medical materials.

If biologics are exposed to floodwaters or subjected to temperatures beyond prescribed readings, the chances of contamination are significant. Biologics in those cases should be disposed of safely.  

Most biological products have specific storage conditions, shown in the product labeling, to preserve their safety, purity, and potency. Bacterial and viral vaccines, allergenic extracts, plasma derivatives, and other medical products need to be stored in refrigerators or reefers. Other products may also need to be stored at controlled room temperatures (i.e., not exceptionally cold or hot).

If there is a power failure, whether due to accident, equipment malfunction, or disruption in the electrical power grid, temperature control systems for product storage may fail.

As well as power failures, there are other possible issues regarding storage. Internal mechanical or electrical problems in the refrigeration or freezer unit on a transport vehicle may also happen while in transit.

Here are some guidelines to follow in the event of a power failure:

Vaccines needing refrigeration or in a reefer storage

Most vaccines are viable at room temperature for a little while, even if some of them are temperature-sensitive. Medicines and vaccines stored in a sealed freezer during a power outage can still be effective unless the power outage duration allows the refrigerator’s (or freezer’s) internal temperature to rise dramatically. The best manner to detect possible spoilage is to install recording thermometers in the refrigerator or freezer section so the temperatures can be read when the power comes back online. The recording will allow workers to see if there were deviations from the recommended temperatures.

Most pharma companies file data with the Center for Biologics Evaluation and Research (CBER) to document the condition of products that were subjected to a rise in temperature, and the length of time subjected to the rise. Companies can then ask for advice from CBER about the effect of temperature/time duration on product integrity.

If the power goes offline

Previously, people in charge of storing refrigerated or frozen biological products took the following steps to safeguard cold storage temperature during a power outage:

They recorded the time of the power failure and refrained from opening freezer doors until the power came back on. This helped to keep internal temperatures low for an extended period of time.

When power returns

The temperature in the refrigerator or freezer was recorded again, once the power returned but before the temperature dropped again. The temperature was then recorded at regular intervals until it reached the range required on the product labeling for cold storage.

The duration of time the products experienced increased temperature exposure was recorded. For example, the temperature of the freezer was   -17 C° (0° F) at noon on the first day when the power failed; -9°C (15° F) at 6 p.m. on the second day, when the power was back online; -12°C (10° F) at 10 p.m. also on the second day 2; and -17°C (0° F) at 7 a.m. on the third day. The data on time/temperature duration allows calculations to be made by the pharma manufacturer, in assistance with FDA as necessary, about the sustained efficacy of the involved products.

If a flood is anticipated

When a flood is expected, the following protocols are enforced to keep the medical products away from the upcoming floods.

For example:

Raise the biological products off the warehouse floors (e.g., on pallets). For those on shelves, secure the items to prevent them from shaking, while keeping the products dry.

For products inside the refrigerators at floor level, rise the units on wheels or platforms to the highest point of the cart.

If flooding happens

Blood products and plasma units

Blood banks and plasma centers have back-up generators and emergency procedures for the storage of these products in case of power outages.

Establishments that collect and store blood and blood components have printed protocols to follow in case of emergency situations. Circumstances affecting the blood supply should be alerted to the FDA.

Advice on protecting medicines after Severe Weather and/or Power Outages

Patients taking medication should be able to rely on proper storage procedures for their medicines, especially during extreme situations. This is especially important for medical products requiring refrigeration.

Medications that are exposed to water, heat, humidity, or other damaging factors can reduce their effectiveness and safety. A power outage could compromise certain medications and, in effect, render them unsafe.

Biologicals that need refrigeration shouldn’t be removed from cold storage if they will be exposed to outside temperatures other than those prescribed by the pharma companies. Temperature-sensitive drugs that are not effective anymore must be replaced with a new supply immediately.

If storage companies need additional clarity on the procedures in protecting their medications, they should contact the pharmacist.

Drugs that have been exposed to the outside environment are considered useable and must be discarded. Tablets or capsules that do not need refrigeration, but were subjected to water, excess heat or humidity, may be adulterated. This includes both prescription and non-prescription drugs. Storage guidelines for over-the-counter medications is written on the package label.

To know the full instructions, FDA’s Center for Biologics Evaluation and Research (CBER) issued the information about the storage and use of temperature-sensitive medical products that were affected by the temporary electrical power failure or flooding.

Power outages caused by severe weather conditions and stalled transportation can delay the deliveries of medicines and supplies, so storage and transport companies should have contingency plans to anticipate these scenarios. Consumers of medicines and other medical products should also be aware of the potential challenges during supply difficulties. Consumers should purchase required items before anticipated problems occur, to ensure that deliveries arrive before their supplies run out.

People who need to evacuate their homes and stay in alternative locations should notify their medical suppliers of the address where they will be temporarily staying so that medications can be delivered accurately.

How do extreme temperatures affect medications?

If medications are placed in excessively hot or cold temperatures, they can degrade quickly. Not all medications are the same. The effect of temperatures beyond the range prescribed by the manufacturer differs by each drug and dosage. Incorrectly storing medication at the correct temperature may cause it lose potency, resulting in a loss of its effectiveness.

What are the concerns about temperature with over the counter (OTC) medications?

Traditionally, powdered or liquid medical components of “pills” were mixed and rolled up like dough or clay. The resulting mixture was then cut or pressed into compacted pills, or encapsulated in digestible hollow shells. It takes little imagination to see how those pills might be affected during a hot summer day or a cold winter night. Modern commercial pharmaceuticals and industrial methods have eliminated many of those worries.

Usually, tablets and hard-shell capsules are resistant to temperature deviations. Liquid and injectable medications are more susceptible to temperature extremes even over short exposure times. Once exposed to very cold or warm temperatures, the medical integrity of the drug can be destroyed.

For example, prescription medicines such as monoclonal antibodies, are the most vulnerable to temperature extremes. Insulin is another common medication that can be affected by temperature, quickly destroying its effectiveness. Light exposure, humidity, and even the container itself can sometimes be the cause of spoiled medications.

Chemical properties of specific drug content determine how vulnerable the product may be. OTC medications can also be affected by temperature extremes. The good news is that most of these products are in dosage forms that are less impacted by temperatures fluctuations.

What are safe locations for storing medicines at home?

There are three important aspects of selecting a good storage location:

  • Access – a place where only adults can reach the medications with ease. The place must prevent access by children or pets.
  • Climate – storage medications away from any heat or cold spots in the house.
  • Habitual routine – Sometimes finding medications can be a struggle. Choose a location habitually used during the day. Medications should be placed were they can be easily found at the prescribed times.

Due to their sensitivity to temperature, light, and humidity, it’s best to store non-refrigerated medications in a cool, dry place, such as a cabinet away from heat sources. Despite being a common location, a bathroom medicine cabinet, is not the best place to store medications. The humidity from bathroom fixtures can affect the medicines.

What to do when traveling with medications

Road trips can be exhilarating and fun, but for those with medications, it can be a harrowing experience. Some medications don’t survive changes in the weather. Keeping them in an air-tight hand-carried bag may reduce potential damage and changes to the medications.

Never leave medications in the checked luggage or anywhere else where temperature conditions are not ideal.

Prescribed medicines must remain in their original packaging to ensure maximum protection from climate changes. For travel abroad, original prescription documents may be required.

What if my medications are shipped to me?

Sometimes medications are not found in the local pharmacy when it’s time to refill. Fortunately, specialty pharmacies and insurers allow their clients to use mail-order services. While it is convenient to deliver the medications to customers’ doors, it can mean more time in transit, increasing the chances of being compromised by the weather.

Mail-order companies, however, don’t always package medications properly to protect them. Temperature protection may be a challenge. A friend or neighbor may need to be authorized to collect delivery packages and store at a safe temperature, if customers will be away from home.

If delivered medications look damaged, or if there is a hint of compromise in the medication, contact a pharmacist to see if it’s safe and effective to use.


As with any vulnerable product, medications cannot do their work if they were exposed to temperature and humidity outside their recommended limits. Not much can be done when extreme weather conditions strike. The best procedure is to take preventive measures such as back-up power supplies, storing medications in secured, sealed containers, and hoping for the best. 


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