On the other hand, the big problem of fossil plastic is its accumulation[5] . For example, if we suppose a constant production of the same amount of PLA and PET (a fossil plastic), after 5 years, higher amounts of PET would b expected to be found because a percentage of PLA should be degraded in the first two years[5] . But if PLA had a short degradation time, we guess people would replace it more frequently by buying more PA products, so higher amounts of PLA could be thrown away and the accumulation rate would increase. We think the trade off between replacing fossil plastics and avoiding an overproduction of PLA should need further analysis to evaluate the real impact of the PLA production process.
According to the previous reflection, we recommend to use PLA for products which will have a short life-time (<2 years), for example plastic cups or bags. On the contrary, for long life-time products such as pipes, chairs or big structures, it would be appropriate to keep using fossil plastics. On the particular case of medical use, we think PLA should be used like suture, because sutures need to be degraded in a short time. Moreover, the degradation would have no nefast consequences on the organism as PLA is a biocompatible material.[6]