The Difference Between PET and HDPE — Which Plastic Should You Choose?

The fundamental difference lies in their physical properties: PET (polyethylene terephthalate) is a rigid, transparent and glossy plastic, ideal for bottles where visibility of the contents is important. HDPE (high-density polyethylene) is semi-rigid, naturally opaque or translucent, and offers superior chemical resistance to solvents, bases and diluted acids. In terms of applications, PET dominates in cosmetics and premium food products, whilst HDPE is preferred for chemicals, industrial applications and aggressive products.

Both are highly recyclable, but PET has the most developed recycling network in France and Europe, with a collection and recycling rate of over 58%. HDPE (code 2) is also widely recycled, particularly for milk bottles and detergent bottles. For eco-friendly packaging, PET allows for the incorporation of up to 100% rPET (post-consumer recycled PET) whilst maintaining transparency. Recycled HDPE, on the other hand, is mainly used for non-food applications.

PET offers good chemical resistance to aqueous solutions, essential oils, diluted alcohols and standard cosmetic solutions. However, it is less resistant to strong organic solvents, concentrated alkalis and undiluted essential oils. For aggressive chemicals (disinfectants, solvents, strong acids), HDPE is clearly preferable due to its broader chemical resistance. PP is also an alternative for certain pharmaceutical and chemical applications.

HDPE is generally slightly cheaper than PET for the same volume, as it is one of the most widely produced plastics in the world. However, the final price of a bottle depends mainly on its shape, volume, the moulding tools available and the quantities ordered. At LABOPICHOT, both materials are available from 5,000 units, with an identical lead time of three weeks.

Yes, both materials are suitable for food contact in accordance with Regulation (EC) No 1935/2004. PET is particularly popular for pill boxes and dietary supplement bottles due to its transparency (allowing the product to be seen). HDPE is preferred for powdered products, water-based liquids and UV-sensitive formulations (thanks to its natural opacity). For capsules and tablets, both our PET and HDPE pill boxes comply with regulatory requirements.

Ask yourself these questions: 1) Does my product need to be visible? → Transparent PET. 2) Does my product contain solvents or corrosive substances? → HDPE. 3) Do I need UV protection? → Opaque HDPE or tinted PET. 4) Do I have specific regulatory requirements (pharmaceutical, food)? → Both are suitable depending on the grade. 5) Do I want eco-friendly packaging made from recycled material? → PET made from rPET. Our technical team is available to advise you free of charge on the best material for your product.