The U.S. Environmental Protection Agency (EPA) has released a draft environmental exposure assessment for Diisononyl Phthalate (DINP), a widely used plasticizer. This assessment, released in August 2024, evaluates the environmental and health risks associated with DINP under the Toxic Substances Control Act (TSCA). The draft focuses on the chemical's potential impacts on aquatic and terrestrial species and is part of the EPA's ongoing efforts to regulate chemicals under TSCA.
What is DINP and Why is it Important?
DINP is a type of phthalate used to make plastics more flexible and durable. It is commonly found in consumer products such as adhesives, coatings, synthetic rubbers, and various plastic materials. Given its widespread use, understanding DINP’s environmental risks is crucial. The EPA’s assessment aims to determine how DINP exposure affects both ecosystems and potentially human health, guiding regulatory actions under TSCA.
Key Findings of the EPA's DINP Assessment
The EPA’s draft assessment identifies multiple pathways through which DINP can enter the environment, posing risks to wildlife and potentially humans. The assessment highlights the following key points:
- Risks to Aquatic Ecosystems:
- Exposure and Concentrations: The EPA’s models indicate that DINP can significantly impact aquatic species, especially in areas near industrial activities where DINP is released into water bodies. Notably, high concentrations of DINP were found in sediments from locations like Kaohsiung Harbor in Taiwan and urban areas in Sweden and Germany.
- Bioaccumulation and Trophic Transfer: Although DINP is not considered highly bioaccumulative, the chemical can still enter the food chain. DINP can accumulate in lower trophic organisms like mussels and fish, which are then consumed by higher trophic levels, including fish-eating mammals such as the American mink. This trophic transfer can increase DINP levels in predators, potentially causing long-term ecological harm.
- Health Impacts on Aquatic Life: DINP exposure poses risks such as reproductive toxicity and endocrine disruption in aquatic organisms. These health effects could reduce fish populations and affect predator species, leading to broader ecological consequences.
- Risks to Terrestrial Ecosystems:
- Soil Contamination: The assessment also indicates that DINP can affect terrestrial species through soil contamination. This contamination primarily occurs through air deposition, which can lead to DINP accumulating in soils, particularly near industrial sites. Small mammals like the short-tailed shrew, which feed on soil-dwelling organisms, are at risk of DINP exposure.
- Potential Health Effects on Land Animals: DINP exposure may lead to adverse health effects in terrestrial animals, including liver and kidney damage, reproductive toxicity, and endocrine disruption. The risks are higher in areas with elevated DINP soil concentrations due to industrial emissions.
- Implications for Human Health:
- Indirect Human Risks: While the assessment mainly focuses on environmental impacts, it also notes potential indirect risks to human health. These risks include consuming contaminated fish or other wildlife with high DINP levels, especially in communities relying on local wildlife for food. Additionally, DINP contamination in drinking water sources could pose further risks.
Next Steps and Public Involvement
The draft assessment concludes that DINP poses significant environmental risks, particularly to aquatic and terrestrial ecosystems. These findings will guide the EPA’s regulatory decisions under TSCA. The EPA encourages public participation in reviewing the draft and submitting comments during the 60-day public comment period. A virtual public meeting will also be held to discuss the findings and gather feedback.
Get Involved and Learn More
To access the full draft assessment and participate in the public comment period, visit the EPA’s official website. The agency urges all stakeholders, including environmental groups, industry representatives, researchers, and the general public, to engage in this process to ensure comprehensive evaluation and regulation of DINP under TSCA.
By staying informed and participating, the public can play a crucial role in shaping how the EPA manages the risks associated with DINP, ensuring the protection of both the environment and public health under TSCA.
