Cryo Box (PP)

Quick Answer: The Cryo Box (PP) is a cryovial storage box moulded from polypropylene, a translucent plastic with broad chemical resistance that can generally be autoclaved. A polypropylene cryo box is a reusable way to store vials in −20 °C and −80 °C freezers and, where its rating allows, in liquid nitrogen storage.

Polypropylene as a Box Material

Polypropylene is the everyday plastic of the life-science lab: pipette tips, microtubes and many racks are made from it. For a vial box, that means a material resisting most acids, alkalis, alcohols and disinfectants that can generally go through a 121 °C steam cycle, so boxes can be decontaminated after a spill or between projects and put back into service.

PP boxes are usually translucent rather than clear, so vial caps show through the lid as shapes and colours, but labels are read with the lid open. Many designs have a hinged or push-fit lid, a numbered grid moulded into the base, and holes to drain liquid nitrogen. Polypropylene becomes stiffer as it cools, so frozen boxes should be handled without dropping or flexing.

Compared with the Cryo Box (PC), the polypropylene box gives up some clarity and low-temperature toughness in exchange for easier autoclaving and wider chemical resistance. The Cryo Box (Cardboard) is the disposable alternative. Grid layout, height and minimum temperature rating for this box are not listed in the title.

Applications

• Storing glycerol stocks of bacteria and yeast at −80 °C
• Keeping aliquots of serum, antibodies or enzymes in cryovials
• Boxes that must be autoclaved after holding infectious material
• Shared teaching freezers where boxes are cleaned between batches of students

Care & Handling

• Autoclave or disinfect boxes after any leak of biological material
• Let frozen boxes warm up before bending hinges or forcing lids
• Label the lid and front with freezer-grade labels, and keep a grid map
• Check the rating before placing a PP box in liquid nitrogen

Specifications

Why Choose LabEquip

Microbiology, virology and cell culture labs that need boxes they can decontaminate and put back into use many times are the main buyers of the PP version. LabEquip lists it in Biology Lab Products with PC and cardboard options; send your vial size and freezer type via our contact page.

Frequently Asked Questions

Can a PP cryo box be autoclaved?

Polypropylene boxes can generally be autoclaved at 121 °C, which makes them easy to decontaminate after a spill. Check the box’s rating and avoid stacking heavy loads on it in the autoclave, as warm plastic can distort.

Is polypropylene suitable for liquid nitrogen?

Some polypropylene cryo boxes are rated for liquid nitrogen vapour phase, but polypropylene becomes stiffer and more brittle at very low temperatures than polycarbonate. Check the rating, and handle frozen boxes carefully.

What chemicals does polypropylene resist?

It resists most aqueous acids and alkalis, alcohols and common lab disinfectants. Strong oxidising agents and some chlorinated solvents can attack it, so avoid those when cleaning.

Why are the lids translucent rather than clear?

Polypropylene is naturally translucent. Cap colours and vial outlines show through the lid, but labels are easier to read with the lid open or from the grid map.

How is the PP box different from the PC box?

The polypropylene box is easier to autoclave and resists a wider range of chemicals. The polycarbonate box is clearer and tougher at very low temperatures, which suits long-term liquid nitrogen storage.

How should boxes be organised in a shared freezer?

Give each box a unique number, label the lid and front, and keep a shared record of box contents and positions. Assign rack shelves to groups so boxes always go back to the same place.

Last Updated: September 2026