All plastics that are used outdoor will eventually suffer from UV and sunlight exposure and will thus “UV degrade”.

A plastics that (bio)degrades or decomposes will create microplastics, and the microplastics will become nanoplastics, etc.

OXO are additives added to plastics to accelerate the UV degradation.

What was the problem that the EU wanted to solve with the EU SUPD: “UV degradation” or “microplastics”?

To solve “UV degradation”, you impose UV protection additives on all outdoor plastics (including plastic packaging because they are littered). Here’s a good example, BASF creates additives against UV degradation: https://www.basf.com/global/en/media/news-releases/2025/10/p-25-204

To solve “microplastics”, (1) you ban all plastic (bio)degrading technologies including all biodegradable and compostable plastics not just OXO (UV), and (2) you impose “UV, heat, friction, moisture, bacterial digestion, etc.” protective additives to plastics.

Why (1)? All biodegradable plastic technologies will release microplastics in the open environment (water and land). And all compostable pastics technologies will release microplastics in the soil and in the food chain through the compost circuit.

Why (2)? All regular plastics that are used or end up outdoor will eventually degrade due to “UV, heat, friction, moisture, bacterial digestion, etc” and create microplastics and nanoplastics.

Is there a hierarchy between biodegradable vs compostable plastics?

The compostable plastics has an additional danger to it: it gets into the food-chain and will disrupt your hormonal system and will eventually create cancers etc.

The most famous compostable plastics are PBAT, PLA and starch based plastics

The most famous biodegradable plastics are OXO and PHA.

In reality, the EU SUPD (EU Single Use Plastics Directive) didn’t want to solve UV degradation or microplastics. The EU SUPD was the result of the lobbying activities of the compostable plastics industry who wanted to get rif of one particular biodegradable technology called OXO. And they were successful.

Did EU SUPD solve UV degradation or microplastics? Nope.

Do you see any difference in the amount of littered plastic waste since EU SUPD? Nope … same amount of plastic waste in the open and marine environment …if not more.

In fact, I would say the plastic waste problem has even increased since EU SUPD.