Phthalates are everywhere in modern life. You can probably find them in the shampoo you use to wash your hair or the soap you use to wash your hands. Being so commonplace, you might reasonably assume (and you would certainly hope) that they don’t have any undesirable effects on our health. However, a growing body of evidence suggests that this may not be the case.
As such, DINCH – a lesser-studied alternative – has been hailed as a safer option and is becoming an increasingly common replacement for phthalates in our everyday products. But what is this surrogate substance? And, more importantly, is it actually safer for us than the phthalates it’s intended to replace?
What are phthalates?
First things first, let's talk phthalates. Phthalates are a group of chemicals known as plasticizers. They are intended to soften plastics, making them less brittle and more durable.
“They are used to provide flexibility in plastics. Think of a rubber ducky and how squishy it is. That’s because of phthalates in vinyl,” explained National Institutes of Standards and Technology researcher John Kucklick in a statement.
To achieve this, they worm their way between the polymer chains that make up the plastic, increasing the space between them. Essentially, they act as a lubricant, allowing the chains more freedom of movement and providing a buffer between one chain and the next.
What products contain phthalates?
Their use isn't limited to plastics: Phthalates can be found enhancing the consistency of all manner of common household items, from paints, nail polish, and hairspray to detergents and household cleaning products.
They can also be found in vinyl flooring, garden hoses, food packaging, and kid’s toys.
Why are phthalates “bad”?
Unfortunately, these virtually ubiquitous chemicals don’t have the cleanest of reputations.
“Some types of phthalates have affected the reproductive system in animals,” state the Centers for Disease Control and Prevention (CDC). Although, the “human health effects from exposure to low levels of phthalates are not as clear,” they add.
But what we do know doesn’t exactly paint phthalates in the best light. They are known endocrine-disrupting compounds, meaning they can interfere with hormone systems. Because of this, they have been associated with various reproductive and fertility issues.
One 2018 study, for example, found that phthalates can disrupt the placenta during the first trimester, which may help explain why they have previously been linked to pregnancy loss and difficulties during childbirth.
Other research has suggested that phthalates could affect testosterone levels and testicular function in adult men.
One study from last year linked the chemicals to 100,000 annual early deaths in the US, particularly due to heart disease. They have also been associated with a whole host of other conditions in the past, including asthma, breast cancer, and autism.
Exactly how much risk phthalates pose is not clear. “More research is needed to assess the human health effects of exposure to phthalates,” the CDC conclude.
Still, there are calls for phthalates to be replaced by other chemicals, such as DINCH. So, how does this substitute compare?
What is DINCH?
Like phthalates, DINCH, or di(isononyl)cyclohexane-1,2-dicarboxylate, is a plasticizer. Its function is similar: to improve the flexibility, durability, and longevity of plastics. It looks similar too – both are colorless oily, liquids.
Unlike phthalates, which were first introduced in the 1920s, DINCH is relatively new on the scene having been used commercially since 2002. In the 20 years since then, it has become a common replacement for phthalates in all sorts of products, including medical devices, food packaging, and toys.
Is DINCH safer than phthalates?
One recent study found that a metabolite of DINCH – a substance produced when the chemical is broken down – was present in 98 percent of urine samples tested. While this may suggest exposure to DINCH is high, the concentration was 275 times less than that of the most prevalent phthalate metabolite.
As for what this exposure might mean for our health, the study did not find that DINCH interfered with estrogen or progesterone – two hormones important in maintaining a healthy pregnancy – in keeping with previous research in human cells that suggests that DINCH and its metabolites do not affect the endocrine system. However, this doesn’t prove that it doesn’t have an effect, the authors are keen to add. As was the party line with phthalates, more research is needed into DINCH’s effect on human health.
Not all studies have come to such positive conclusions on DINCH. One, from back in 2015, found that one of DINCH’s metabolites can disrupt metabolic processes in animal tissues and “may interfere with the endocrine system in mammals”.
Again, the researchers advised their findings be taken with caution: “It is currently difficult to assess whether DINCH exposure represents a risk to human health before we conduct more research on in vivo models,” said study lead author Dr. Vassilios Papadopoulos in a statement.
Another study found that DINCH exposure “likely [caused] premature aging of the testes and impaired liver metabolic capacity” in the male offspring of exposed pregnant rats.
Of course, these studies are in animals not humans. However, very little research has been done into the potential effects of DINCH on human health, especially when compared to the expansive literature on phthalates.
For now, DINCH continues to be used as a phthalate replacement, but research is ongoing into its potential impact on our hormones and health. Unfortunately, it is simply too early to say whether or not DINCH is “safer” than its ill-reputed counterpart just yet. But with its growing prevalence in plastics, let’s hope we don’t have to wait too long to find out.