Working in a lab, you may have had the responsibility at one point or another of procuring various bottles, containers, and other storage mediums for your team. While searching through endless variations of plastic lab supplies, you may see a myriad of acronyms, like HDPE and PET. With these options, it may be confusing trying to find the right container that will work for your lab’s applications. Trying to pronounce some of these plastics’ names is tough enough, let alone trying to understand their different properties. We’re here to help clear up some of the differences between two of the most common plastic bottle resins in our mashup of High Density Polyethylene vs Polyethylene Terephthalate.

High Density Polyethylene

High Density Polyethylene, also identified as HDPE, is a thermoplastic polymer commonly used to manufacture plastic laboratory supplies like beakers, bottles, flasks, specimen containers, test tubes, and many others. HDPE is exceptionally strong thanks to its linear structure. With its light weight, durability, and malleability, HDPE is a perfect material for injection molding. HDPE’s strength and chemical resistant properties makes it an ideal candidate for vacuum bottles. HDPE bottles are frequently used in the biotechnology field for cell harvesting, degasification, and liquid aspiration.

HDPE can withstand short periods of heating with its melting point ranging from 259°F - 267°F (126°C - 131°C) but starts weakening at 160°F. HDPE Bottles and laboratory supplies made from HDPE should not be used in applications that require autoclaving.

RELATED READ: Lab Plastic’s Guide

Polyethylene Terephthalates

Polyethylene terephthalate, or PET, is a shatterproof, light weight, and inert material derived from ethylene glycol and terephthalic (try saying that 10 times fast) acid. You may also know it as polyester and it is the world’s most common synthetic fiber. It’s used for food packaging and personal care products due to its non-reactive properties. PET bottles are transparent, but color may be added to make them opaque. PET bottles are temperature resistant up to 145°F.

Both HDPE and PET are great for various applications both inside and outside the laboratory as they are inert and have good chemical resistance. If you need a container that’s more durable and temperature resistant, HDPE is the plastic of choice. If you require a crystal-clear container and can't use glass, reach for the PET container. Just try not getting tongue-tied while asking for it by name.

RELATED READ: Polypropylene vs Polystyrene

Updated January 8th, 2020