You probably use products with DINA every single day without knowing it. That flexible phone charger cable, the soft plastic tubing in your medical equipment, even the clear film wrapping your food—many of these contain a chemical called Diisononyl Adipate, or DINA.
Here’s what makes DINA interesting: it’s a plasticizer that keeps plastic soft and bendable without the health concerns associated with older plasticizers like phthalates. As companies work to eliminate harmful chemicals from products, DINA has become one of the most popular alternatives.
What Is Diisononyl Adipate (DINA)?
Definition and Basic Chemical Structure
DINA is a clear, colorless liquid that works as a plasticizer—essentially a chemical additive that makes rigid plastics flexible. Think of it as a lubricant between plastic polymer chains. Without it, PVC (polyvinyl chloride, a common plastic) would be stiff and brittle.
Chemically, DINA is a mixture of esters made from adipic acid (a compound with a six-carbon backbone) combined with branched alcohols containing nine carbon atoms. The exact formula is C26H50O4, though the variations in how those atoms arrange create slightly different versions of DINA in the mixture.
In its pure form, DINA is practically insoluble in water—meaning it won’t dissolve if you drop it in a glass of water. It’s much more compatible with oils and solvents, which is why it works so well inside plastic materials.
How Does DINA Make Plastics Flexible?
The magic happens at the molecular level. PVC is made of long chains of atoms locked together tightly. These tight chains make the material stiff and prone to cracking.
When you add DINA, its molecules squeeze between these polymer chains. They act like tiny wedges, pushing the chains apart just enough to create room for movement. The polymer chains can now slide past each other more easily—exactly what you need for flexibility.
Here’s the key difference between different plasticizers: how well they fit between those chains and how strongly they stick around. DINA’s molecular structure means it stays put (low volatility) while still providing excellent flexibility, even at cold temperatures. This makes it ideal for products that need to be both flexible and durable.
The process happens during manufacturing when DINA is mixed into melted PVC. As the mixture cools, DINA becomes trapped within the plastic matrix, continuing to do its job of keeping the material flexible for years.
How Does DINA Compare to Other Plasticizers?
DINA vs. Phthalate Plasticizers
For decades, phthalate plasticizers dominated the market. The most common was DEHP (diethylhexyl phthalate). But in recent years, concerns about health effects—particularly reproductive and developmental issues—led regulators worldwide to restrict or ban phthalates.
Here’s how DINA stacks up against the old phthalate standard:
| Feature | DINA (Adipate) | DEHP (Phthalate) |
|---|---|---|
| Chemical Base | Adipic acid ester | Phthalic acid ester |
| Regulatory Status | Fewer restrictions, considered safer | Heavily restricted/banned in many countries |
| Low-Temperature Flexibility | Superior—works well in cold | Good, but not as effective |
| Health Profile | Lower toxicity concerns | Endocrine disruptor concerns |
| Application in Food Packaging | Approved for food contact | Banned for direct food contact in most regions |
| Volatility | Very low (stays in product) | Moderate (can migrate and evaporate) |
The big shift happened because phthalates can leach out of products and into food, drinking water, and the environment. They’ve also been linked to reproductive issues in animal studies, which prompted regulators to act. DINA, by contrast, is far less volatile and hasn’t shown the same concerning health patterns.
That said, DINA is still relatively new compared to phthalates, so ongoing research continues to monitor its long-term effects.
DINA vs. Citrate Plasticizers
Another alternative to phthalates is citrate plasticizers (derived from citric acid). On paper, they sound great—they’re natural and biodegradable. But they have a major drawback: they’re highly volatile, meaning they evaporate or leach out of plastic over time.
This volatility is actually a problem for most industrial applications. If your cable insulation loses its plasticizer after a few months, it becomes brittle and cracks. Same with flooring or roofing materials. Citrate plasticizers work fine for temporary applications like shower curtains, but they’re not suitable for products that need permanence.
DINA’s low volatility makes it far superior for anything requiring long-term flexibility: industrial cables, automotive hoses, flexible tubing in medical devices, and durable consumer goods.