Phthalates – not great?

Diethyl phthalate (DEP), the most common phthalate in cosmetic and personal care products in Australia, is not an endocrine disruptor. This is widely accepted and even acknowledged by anti-phthalate campaigners.

‘DEP is not generally characterised as an endocrine active compound’
Silent Spring Institute, 2012⁴

DEP also has low toxicity and low irritancy.

It is unhelpful that many studies, websites, news articles etc, assert that phthalates are classified as endocrine-disrupting chemicals when DEP, a phthalate, is not. This kind of blanket statement can cause unnecessary alarm.

Australia’s industrial chemicals regulator comprehensively assessed diethyl phthalate (DEP) and eight other phthalates in 2011.⁵ This was to determine the potential health risks to adults and children from these phthalates in toys, child care articles and cosmetics, especially when used repeatedly or for long periods. As a result, a limit of 0.5% DEP for sunscreens, personal insect repellents and body lotions was set. This was because these products are applied to large areas of the body, for long periods. The regulator noted that this was ‘a cautious approach’ that ‘would be protective for the public, particularly young children’. It was due to uncertainty on whether higher levels could have adverse effects in infants or young children and applied on large areas of the body. 

In March 2007, the Scientific Committee on Consumer Products (SCCP), an independent committee providing scientific advice to the European Commission, reviewed the safety of DEP.⁶ It concluded that ‘new studies on DEP…did not provide sufficient new information to change the conclusions’. That is, that use of DEP in cosmetic products is safe. This Committee also evaluated the safety of other phthalates found in cosmetics and concluded that all of these at the levels present posed ‘no measurable risk for the consumer’ or did ‘not seem to be a concern for human health’.⁶ 

Different phthalates have different properties. The health and environmental effects of phthalates have been extensively researched due to their widespread use. The data on phthalates continues to be reviewed by regulatory agencies around the world.

Several phthalates, including dibutyl phthalate (DBP), diethylhexyl phthalate, diisobutyl phthalate and di(methyloxyhexyl)phthalate are banned in cosmetics in Australia. This was based on potential health risks associated with these phthalates, mainly reproductive toxicity. Australia’s industrial chemicals regulator noted that a DBP ban was ‘a cautious approach…given the level of uncertainty regarding both the health effects and levels of exposure for different population groups’.⁷  

European regulations also ban seven phthalates in cosmetics (not DEP) due to concerns that they have endocrine-disrupting properties.⁸

The US FDA has taken a different approach. As it ‘does not have evidence that phthalates as used in cosmetics pose a safety risk’,⁹ no restrictions are imposed.

Why this difference? It’s because of fundamental differences in the EU and USA’s approaches to chemical regulation. The USA has a risk-based approach, allowing substances until there is clear scientific proof of harm. Kind of like ‘innocent until proven guilty’. The EU’s approach is based on the Precautionary Principle, which bans or restricts substances before harm is fully proven if there is reasonable concern. Kind of like, ‘presumed guilty until proven innocent’. With phthalates, Australia is taking more of an EU-type approach. 

Yes it’s true.

Let’s look at dibutyl phthalate (DBP) as an example, remembering that it’s banned in cosmetics in Australia and the EU. DBP was used in nail polish, at a maximum concentration of around 15% (or approximately 2,250 milligrams of DBP per 15 mL bottle).

According to AICIS, the Australian industrial chemicals regulator, the level below which DBP has no adverse effect is 10 milligrams per kilogram bodyweight.¹⁰

So, a 70 kg person could consume (literally eat) 700 mg of DBP per day every day – a third of a bottle – without any problems. And this is assuming that every phthalate molecule gets into the body, which is not realistic for a nail product. 

But DBP is banned! Yes. Because DBP was not proven safe, not because it was proven unsafe. This is the Precautionary Principle in action. Could anything can be banned if there is a suggestion of risk? Potentially.

Let’s look at that 2024 headline again, ‘Kids using lotions have higher levels of hormone-disrupting toxins...Children using personal care products had more phthalates, which are linked to reproductive and metabolic diseases’.³

What parent, grandparent, aunt or uncle wouldn’t be worried? But it’s not a helpful or indeed very accurate headline, it turns out. Let’s have a look at why.

First, there is that incorrect generalisation again – DEP is a phthalate but is not linked to reproductive and metabolic diseases.

Second, ‘toxins’? A toxin is a poison from a natural (plant or animal) source. Phthalates in cosmetics and personal care products are synthetic. (OK, perhaps this is being overly critical…)

Third, the study results did not support a direct link between personal care products and urinary phthalate concentrations. For example, ‘girls tended to use more skin care products than boys’¹¹  but ‘boys tended to have higher [phthalate] levels than girls’.³ And, ‘the study found no difference in the levels of the chemical in the urine of those who used “phthalate-free” products compared with those who did not’.³  Yep – phthalates must have been from other sources, not just as ingredients in personal care products. Not what the headline suggests.

Numerous studies have found phthalates in the human body. According to Dr Joe Schwartz, ‘It comes as no surprise that with phthalates being ubiquitous, they can be detected in our bloodstream and urine. The question is whether this has any significant health consequences.’¹²

And that question is still to be definitively answered for many phthalates. No proven link between different phthalates in cosmetics and various health concerns exists.

A 2012 study found an association between urinary levels of four phthalates and increased risk of diabetes in women.¹³ Cue headlines such as ‘Skin cream: killing you softly?’¹⁴ and other similar anti-cosmetic sentiments. 

Should women be worried? No.

According to the American Council on Science and Health, the study upon which this myth is based was ‘flawed beyond any semblance of scientific validity’.¹⁵ 

Most significantly, the four phthalates weren’t even the types found in cosmetics. Not only was no link between diabetes and the phthalates in personal care products proven, but no evidence that these four phthalates caused diabetes was provided.  

What about reverse causation? It’s likely that diabetic women had higher levels of specific phthalates in their urine because they were regularly taking medications or exposed to medical devices containing phthalates.