Both Diethylhexyl-phthalate (DEHP) and Dibutyl Phthalate (DBP) are phthalates. Phthalates are plasticizers that are added to plastic materials to make them softer and more flexible.

Because phthalates are not chemically bound to the material they are added to, they can be released from the products that contain them, for instance into water and air. The emission of phthalates occurs during all the stages of the lifecycle of a product from production, through use, to disposal.

There is public concern about phthalates because of their widespread use and occurrence in the environment as well as their potential effects on human health. The US FDA is asking manufacturers to reformulate products containing DBP and DEHP excipients to cut the risk of toxicity.

There are more information in FDA’s article: Guidance for Industry; Limiting the Use of Certain Phthalates as Excipients in CDER-Regulated Products.

 

Why phthalates can not be added to 3D printer filament materials?

Since PLA is brittle and vulnerable to humidity, some filament manufacturers added phthalates to PLA material as an easy approach to reducing the fracture. We considered it extremely dangerous since the printer hot end heat the filament to melt during printing and the process also vaporizes phthalates into the air. Therefore, the risk can be largely increased.

To deal with fracture issues , we add non-phthalates based additives to improve the performance and lifespan of PLA filament. Due to the biodegradable nature of PLA material, it is recommended to store filament in a sealed plastic bag or box after each print. In case the filament got damp, you can bake it in an oven with 50-degree celsius for about an hour to restore its dryness.