Are the materials said to be oxobiodegradable actually biodegradable

They do not comply with any current biodegradabihty norm. However, after their oxidative phase (which can only occur when there is sufficient oxygen, heat and light), they may show some biodegradability, slow, although faster than those with added polyolefins. 

The norm NF EN 13432 is strictly restricted to packaging as defined by the European directive 94/62/CE. However, compliance can be obtained with NF EN 14995, a certified copy of NF EN 13432, but it is restricted to all materials except packaging. Failure to observe this regulation could lead to prosecution for false 

---