Polylactic Acid (PLA) is a widely used bioplastic found in various daily products. As its use expands, questions about its safety and potential toxicity arise. This article explores PLA’s properties and its interactions with human health across applications, providing clarity on its safety profile.
What is Polylactic Acid (PLA)?
Polylactic Acid (PLA) is a thermoplastic derived from renewable, organic resources. Unlike most traditional plastics produced from fossil fuels, PLA originates from fermented plant starches such as corn, sugarcane, or cassava. This process involves converting the sugars in these plants into lactic acid, which then undergoes polymerization to form polylactic acid.
PLA is characterized by its biodegradable nature and thermoplastic properties, meaning it can be molded and reshaped when heated and solidifies upon cooling. Its versatility has led to its adoption in numerous applications, including packaging materials, disposable cutlery, textiles, 3D printing filaments, and medical devices.
PLA and Human Health: Key Considerations
Understanding how PLA interacts with the human body is central to assessing its safety. Its widespread use necessitates a detailed examination of its safety profile across applications.
PLA is widely used in food packaging due to its recognized safety for food contact. Regulatory bodies consider it safe because of its inert nature, which means it has a low likelihood of leaching harmful chemicals into food under normal conditions. Minimal migration from PLA typically consists of lactic acid, a substance naturally present in the human body and considered safe. However, PLA has a lower heat resistance than some other plastics, making it less suitable for very hot foods or liquids, as high temperatures could lead to deformation or increased migration.
PLA’s use in medical applications further supports its safety for human interaction. It is employed in biomedical contexts such as dissolvable stitches, drug delivery systems, and temporary implants. PLA’s biocompatibility, meaning it can safely exist within biological systems without causing an adverse response, and its biodegradability are primary reasons for its selection in these sensitive applications. These medical-grade PLA products break down harmlessly within the body over time, eliminating the need for surgical removal.
Fumes during 3D printing with PLA are a common consideration. When PLA is heated for 3D printing, it can release volatile organic compounds (VOCs) and ultrafine particles (UFPs). Compared to other common 3D printing filaments like ABS, PLA generally produces fewer and less toxic emissions, with lactide as the primary VOC. While PLA emissions are less hazardous than those from materials like ABS (which can release styrene), good ventilation practices are recommended to minimize exposure.
When PLA degrades, it breaks down into lactic acid, water, and carbon dioxide. Lactic acid is a natural metabolic product in the human body, eliminated through normal physiological processes. This contributes to PLA’s favorable safety profile, as its degradation products are non-toxic and easily processed by the body.
Regulatory Standards and Safety Assurance
The safety of Polylactic Acid for various applications is substantiated by regulatory bodies worldwide. In the United States, the Food and Drug Administration (FDA) has approved PLA for food packaging, particularly under specific temperature and food type conditions. The FDA has recognized PLA as “Generally Recognized As Safe” (GRAS) for its intended uses in food-contact articles, following migration studies showing minimal risk.
Similarly, the European Food Safety Authority (EFSA) has deemed PLA safe for food contact materials under certain conditions. These regulatory approvals indicate PLA undergoes rigorous scrutiny and meets high safety standards for human contact applications, including food and medical uses. Regulatory oversight dictates purity standards and acceptable use conditions, ensuring PLA materials comply with established safety benchmarks.