After a woman’s eggs are frozen in a lab, they’re kept in a cryogenic storage facility, preserved at the low temperature of -196ºC, until she’s ready to use them. At that temperature, all biological processes—including aging—stop, effectively freezing the eggs in time.

As natural disasters, like hurricanes, dominate the news, many of our patients want to know: Will my eggs be safe in the case of a prolonged electrical outage?

The short answer: yes—as long as they’re in a high-quality storage facility, like our storage partner New England Cryogenic Center. Here’s why:

Nitrogen storage does not require electricity.

The good news: liquid nitrogen is the best, most reliable type of long-term cryostorage specifically because it doesn’t need electricity to maintain its low temperature.

There are two types of liquid nitrogen tanks. In the first, called immersion storage, frozen materials are stored in a tank filled with liquid nitrogen. In the second, called vapor storage, frozen tissues are stored in the nitrogen vapors above a shallow reservoir of liquid nitrogen; because nitrogen’s boiling point is so low (-195.79 °C or -320 °F), it’s constantly vaporizing, and the vapors are cold enough to keep tissues frozen.

Both tanks can keep human cells, like oocytes, frozen at very low temperatures for a few weeks or more, depending on their size and design. Eventually, the nitrogen will completely vaporize, and the tanks will need to be refilled.

A “gravity-feed” nitrogen system can refill tanks in the case of a power outage.

Once again, there are two methods to keep liquid nitrogen storage tanks at the proper nitrogen levels: automatic fill, or gravity feed. Auto-fill uses electronic sensors to monitor the nitrogen level inside and dispense liquid nitrogen from storage “dewars” (containers) as necessary. This requires electricity or battery backup, and is not reliable in the case of a natural disaster.

Gravity-feed dewars, on the other hand, supply liquid nitrogen without electricity. Here’s how it works: the gravity feeder is positioned above the nitrogen tank(s), and a seal is made between the two devices. Nitrogen is dripped through tubes from the bottom of the gravity feeder—as the liquid level in the lower tank(s) drops, it’s replenished from above.

New England Cryogenic Center, our long-term storage partner, has a 9,000-gallon gravity-fed liquid nitrogen tank on premises for use in case of a prolonged power outage.

Electricity required for monitoring and security can be provided by generators.

Your frozen eggs are invaluable—so it’s extra important that they’re kept secure.

Our partner facility NECC is monitored 24/7 with video surveillance, alarm systems, and motion detectors. Additionally, each storage tank has its own separate monitor—and multiple monitoring systems—in place to ensure proper tank temperature and liquid nitrogen levels.

All of these systems require electricity, which is why NECC has backup generators on premises that can power these systems in the case of an outage.

“On-site storage” at many clinics is insufficiently safe.

The unfortunate truth is that not every clinic that provides fertility preservation services implements the safeguards we’ve outlined here. At many clinics, “on-site storage” is the norm, meaning frozen eggs and other materials are stored at the clinic itself, often in a small space like a converted closet. The result is a bunch of liquid nitrogen tanks crammed together without the benefit of surveillance, security, or backup nitrogen refill systems—which could put valuable frozen materials at risk, especially in the case of a natural disaster.

Extend Fertility’s storage partner NECC is an industry leader in safe, secure cryostorage.

Eggs frozen at Extend Fertility are placed in off-site storage at NECC, which offers a highly tested, failsafe system. At NECC, frozen eggs are protected in three ways: one, the liquid nitrogen inside the storage tanks will keep the eggs frozen without power; two, gravity-feed dewars will refill those storage tanks, no electricity required; and three, powerful backup generators will fuel security and lab monitoring systems.

It’s important to fully understand the security and emergency measures put into place by your frozen tissue storage facility. For more information about New England Cryogenic Center—and why Extend Fertility chose to partner with them—feel free to contact us.