With the uproar over plastic waste, somebody at Mercadona has decided to change from cartons to plastic bottles for all fresh milk. 
We need to realise that that not all plastic is bad. The recent hoo-hah is wrongly giving the whole plastic production and their uses a bad name.
High Density Polyethylene (HDPE) plastic bottles are a popular packaging choice for the milk and fresh juice markets.
Firstly, it’s the only plastic bottle type that can be used as a monolayer bottle for sterilized milk, or as a bottle with barrier layers for UHT.
HDPE is also one of the easiest plastic polymers to recycle. The plastic can be easily sorted and cleaned.
Cartons however are made by 7 layers of different materials (75% of cardboard, 20% of plastic, and 5% of aluminium).
To recycle cartons, different processes are needed to separate all the individual layers and some municipalities are reluctant to pay the costs needed to do this.
However, this biggest problem with recycling carton waste for countries like Spain is the amount water involved in the process. It takes a tremendous amount of water to recycle the 7 layers and so is not always an option for some countries where water is a problem.
The only option then is for the carton to be either incinerated or sent to landfill, both of which come with added problems.
So, it might just be that Mercadona has in fact made the best decision.
