Earthquakes, hurricanes, tsunamis, these disasters can wipe out a power grid and compromise the delicate samples and expensive reagents that need to be stored below freezing. The most well-prepared labs, with redundant systems and back-up generators, still have only a finite time before they go dark and their freezers fail. For labs with fewer resources, even short, local power outages can compromise their cold storage.
What do you do when the grid goes down, the lights go out, and the temperature in the deep freezer begins to rise? If you’re lucky, you might have access to dry ice, the workhorse of emergency freezer management, but, in disaster scenarios, dry ice may not be readily available. Fortunately, there is another option if you need to drop the temperature to -20C in a hurry and your resources are limited:
Make ice cream.
Ice cream is made by mixing large-granule rock salt (sodium chloride) with ice. Ice requires energy to melt, and by adding salt, you’re lowering the freezing point and increasing the amount of energy needed to trigger a phase change. Give the mixture a vigorous stir and you’ll see some ice phase into water, than back into ice. Drop a thermometer in, and you’ll see the temperature drop quickly. Practically, you’ve just made ice colder.
How much colder? Mixing 30% rock salt to 70% ice will lower the temperature to between -20 and -30C, cold enough to keep most samples safe, at least for a while. A 50-lb bag of rock salt costs less than $10, so grab a couple, stick them somewhere out of the way, and hope you never need to use them.
It’s not just natural disasters that can knock out your freezer. A blown motor or other mechanical failure can take your critical systems offline. A HappiLabs Lab Consultant can help you pick the best, most reliable equipment for your laboratory.