Cold Storage Safety the Topic for January 2018 Meeting
by Renee Witherspoon, CSP, CIH, CHMM, Past President (2012-2015)
On January 16 the ASSE South plains Chapter welcomed Rose Christina, Cold Storage Specialist with ThermoFisher Scientific. Kate McKee, Territory Sales Representative with ThermoFisher, coordinated Rose’s visit to Lubbock.
Rose was able to conduct two presentations, the first was a Lunch-and-Learn at TTUHSC; the second, an evening presentation for the South Plains Chapter.
She began her presentation by explaining that although cold storage refrigerators and freezers are not the most exciting piece of equipment in a lab or clinic, purchasing laboratory-grade equipment will come with piece of mind knowing that critical samples and vaccines will not be destroyed because of temperature fluctuations which are common in home-use models.
Some of the most common types in research labs are the ultra-low-temperature (ULT) freezers (called minus 80 freezers). These freezers are specifically designed to protect samples. Although called the -80°C freezer, the typically temperature range is –86 °C to –45 °C.
If these freezers are not properly maintained or become full of ice it can result in sample loss, which has the potential to wipe out years of research or valuable inventory.
She reviewed some best practices that include:
- Be organized so you can get in and out as quickly as possible
- Care should be taken when breaking hard ice from a freezer. Never tear ice from a freezer. Look for snowy ice as this is not hard on the freezer.
- To remove ice is use an ordinary wet-dry vac.
- Keep the vacuum relief port free and clear because you might not be able to get into the freezer. If you are unable to get into the freezer, use a thin flat knife that can break the vacuum seal.
- Don’t store stuff on top of a freezer.
- Autoclaves and freezers should not be in the same areas. Vents from an autoclave should be away from any freezer.
- Consider back-up power for ULT freezers with critical samples that may thaw due to power outages or mechanical failure.
At the evening meeting she went into more detail on the different types of refrigerators/freezers and proper selection, including those used for blood banks, flammable materials, explosion-proof, pharmacy, and for general laboratory use.
Key for safety professionals is that low-temperature storage in freezers or use of Liquid Nitrogen present unique hazards to personnel because of the extremely cold conditions. Liquid nitrogen is a cryogenic liquid. Cryogenic liquids are liquefied gases that have a normal boiling point below –90°C or –130°F.
Use of insulated gloves and lab coats that protect the skin from exposure should be required to prevent “cold burns.” If working with a liquid nitrogen freezer and retrieving vials, it is also important to wear a face shield to prevent splashes to the face.
Improperly sealed glass ampoules can also be a significant safety hazard when being retrieved from liquid nitrogen because they may explode. She recommended storage in the vapor phase, but if vials must be retrieved from the liquid phase of the freezer in the vapor phase of the same freezer for a minimum of 24-hours. Remember to thaw and open vials containing hazardous biological materials inside a biological safety cabinet. Broken or leaking ampoules are a potential source of contamination and may survive even with the extremely cold temperatures.
Items requiring a laboratory-grade refrigerator or freezer include:
Antibodies, APIs, Bacteria/Viruses, Biologicals, Blood Products, BOD Protocols, Cell Culture Media, Chromatography Apparatus, Chromatography Instrumentation, Clinical Samples, Control Materials, Cytokines, Derived Cells, Enzymes, Laboratory Reagents, Microbiology Cultures, Patient Medication, Patient Specimens, Plasma/Serum, Proteins, Reagent Test Kits, Solvents, Tissue Blocks/Slides, Tissue Cultures, and Vaccines.
Rose finished up her presentation with some examples of personal protective equipment, cryopreservation accessories and what she called a Smart-Tracker that monitors cold storage in transit. It is some of the latest technology available where a smart phone can be used to check temperature readings during transit.
A copy of her presentation will be made available soon on our website.
On behalf of the South Plains Chapter and TTUHSC, we would like to thank Thermo Fisher’s Rose Christina and Kate McKee for making the excellent presentations. We would also like to thank Kate for providing a nice lunch for our attendees at the Lunch and Learn.