By Megan Hickey

CHICAGO (CBS) — It is absolutely vital that Pfizer’s COVID-19 vaccine is kept at 70 degrees below zero. For that to happen, the Federal Aviation Administration had to make some changes for how much dry ice is allowed on planes to allow more of the vaccine to be shipped at once.

The typical load has been about 3,000 pounds, but the FAA says it is now allowing up to 15,000 pounds of dry ice for COVID-19 vaccine flights. CBS News has confirmed that Chicago-based United Airlines has already flown vaccines from Brussels to Chicago. This change will allow them to fly much more of the vaccine.

READ MORE: LIVE UPDATES: 130 Homes Damaged In Tornado In West, Southwest Suburbs As Dangerous Storms Hit Chicago Area Sunday Night

The 3,000 pound limit was in place because there are some hazards associated with large quantities of dry ice. When dry ice melts it does not pool on the ground or form a puddle. It instead changes into a gas, so in poorly ventilated, enclosed spaces, it can cause carbon dioxide overexposure. The other obvious issue is frostbite if there is direct contact with skin.

READ MORE: Chicago Weather: Second Sunday Night Tornado Confirmed; Cool And Clear Monday Night

The FAA has provided further safety protocols to carriers who are transporting these large quantities on ice. The FAA said it has supported several COVID-19 vaccine flights already, and there will surely be more to come.

MORE NEWS: Assessing The Damage: Tornado That Ripped Through DuPage County Classified As EF-3

Also From CBS Chicago:

Megan Hickey