Carrefour Plastic Bag

Honestly, I'm curious to find out if anyone knows what does biogredable actually means... I've never read or heard such word until today when I went shopping and they've put the stuff in the plastic bags even before I get to say 'No need plastic'...

.:The plastic bag:.

I tried to google and went to dictionary.com and those sites were quite helpless. If it's a typo error that Carrefour Malaysia has made. I'm very surprised. O_o