Renewable materials are materials obtained from agricultural or marine resources. Renewable resources are all the resources from animal, microorganisms, and vegetal production.
The environmental impacts of packaging are mainly related to the impacts of their constituent materials. Shifting from fossil to renewable resources can then be positive regarding the environmental indicator significantly affected by the use of fossil resources.
Check the environmental impacts (vs the material substituted).
Renewable does not mean sustainable if there are many industrial steps from resource to usable material.
Check the functional properties (vs the material substituted).
If the properties are not the same, is there any negative consequence on environmental impacts?
Improve the properties if the material is not adapted to its technical functional specifications.
e.g. surface treatments and insert of barrier layers if the initial material barrier level is not adapted to the targeted application.