Biocompatibility hints  

Commercial SLA, DLP & LCD 3D resins as sold are photoreactive liquid resins, which may cause at least skin, eye and mucosa irritation. Consequently, any photoreactive liquid resin cannot be considered safe biomedical devices, nor safe food packaging, despite some 3D resins suppliers advertise and market their 3D resins as certified biomedical devices, or food packaging. This misleading marketing exercise creates confusion giving a false sense of legal coverage.   

There is always some unreacted monomer, resin, reaction byproducts and catalyst residuals trapped in the solid printed polymer material (leachable or extractable), which elimination is beyond the control and competence of any 3D resin supplier, which should not be used as raw materials, and if used need to be replaced by safer alternative ingredients.

Any potential residual unreacted monomer needs to be cured, extractables and leachables residuals and by products need to be removed and cleaned properly by the device manufacturer to avoid their later extraction by eg the saliva and their absorption by the skin and/or mucosa of the mouth.

Final users of biomedical devices and food packaging should not be at potential risk of absorbing any toxic products.

In practice, existing certifications of biomedical devices sometimes ignore the importance of using safe raw materials. As example, there is a bunch of "certified" resins in the market which contain substances suspected of e.g. damaging fertility of  the unborn child. A basic analysis of the Material Safety Data Sheets MSDS of few commercial 3D resins can verify this concern. This sort of toxic ingredients are prone to being absorbed by the body despite being used in "certified" resins.