PET vs HDPE: understanding two common packaging plastics

Read the code in context

Check the base and lower edges for the number and letters. A close-up makes shallow moulded markings easier to read, while a wider photo keeps the container and its purpose in view.

Treat the body, cap and sleeve as components. A marking or instruction may describe one part rather than the entire package, so note which piece it belongs to.

Make a simple comparison

For each object, record its use, marking and any manufacturer information. “Drink bottle, marked 1 PET” gives you a specific entry you can compare with “container body, marked 2 HDPE.”

A material identifier app adds another way to explore the surface. Materium uses visible features and object context to build an assessment, which you can read alongside the product’s marking.

Find the relevant collection route

Once you have identified the resin, check the accepted-item guidance for your own collection service. EPA guidance in the US and Recycle Now’s UK symbol guide offer useful background; your provider supplies the local answer.

Save the scan and keep the marking and collection reference in your notes. For product care or suitability for a particular use, refer to the manufacturer’s instructions. This gives your packaging comparison a clear material identity and a practical context.

Material reference

• PET: properties and identification clues
• HDPE: properties and identification clues
• Polypropylene: properties and identification clues

Keep exploring

• Plastic recycling numbers: a guide to resin codes
• Is polypropylene recyclable? Understanding PP collection routes
• How to identify materials from a photo with Materium