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    Controversial Phthalate Plasticizer Found Safe For Children’s Toys, Confounding Activists
    By Jon Entine | October 9th 2012 01:00 PM | 16 comments | Print | E-mail | Track Comments

    Bumbling coverage on phthalates underscores how activist journalism endangers ‘public science’

    Last year, campaigning journalist Susan Freinkel noted that she wrote her anti-chemical book, Plastics: A Toxic Love Story, because she was shocked about how much modern society relied on plastics. In her mind, “synthetic materials” equated with poor health, pollution and western gluttony. 

    Freinkel’s perspective reflects a familiar and distressing trope in science journalism. Rather than contextualize an issue, activist reporters often dramatize it. Costs are rarely weighed with benefits. The risks of not using a substance are almost never balanced against the risks of using it. Like many reporters, Freinkel started out with a premise—plastics=toxic=bad—and then loaded the dice to hammer home that simplism.

    What brings Freinkel’s book to mind is the recent news that Australia’s premier science risk assessment agency comprehensively assessed a common phthalate, DINP (diisononyl phthalate), used in toys and child care products and found that it poses no serious health concerns. That determination, which corresponds with reviews by major science bodies around the world, stands in contrast to the perspective on phthalates and most chemicals advocated by Freinkel and other activist journalists and NGOs.

    Phthalates are plasticizers used to increase the flexibility and durability of a product. There are dozens of different types, but nine major ones, used in thousands of consumer and industrial applications including, cosmetics, cables, flooring, medical devices and children’s backpacks and toys. DINP is one type of phthalate.

    According to the new review by the Australian government’s National Industrial Chemicals Notification and Assessment Scheme (NICNA), “Current risk estimates do not indicate a health concern from exposure of children to DINP in toys and child care articles even at the highest (reasonable worst-case) exposure scenario considered. The scientists concluded: “No recommendations to public health risk management for the use of DINP in toys and child care articles are required based on the findings of this assessment.”

    The finding revoked the categorization of DINP as a “priority existing chemical,” meaning that manufacturers and importers wishing to use it in a product need no longer apply for yet another assessment. Australia’s study is the latest in a long line of international government reviews affirming that DINP is safe for current uses.

    Few chemicals on the market today have undergone as much scientific scrutiny as phthalate plasticizers. Environmentalists and industry groups can draw upon a plethora of studies, human and animal, in a hopeless attempt to definitively prove phthalates are dangerous or harmless. As in most reviews of chemical substances, science rarely yields perfect clarity. But in this debate, clarity is not the goal of phthalate critics who hold a distinct if perverse advantage. They are not trying to reach a “weight of evidence”conclusion (if they were, there would be few if any restrictions on phthalates); rather, their goal is to stir just enough concern that politicians will ban or heavily restrict the chemical based on precautionary fears.

    Phthalates, Freinkel breezily writes in her book that phthalates “play havoc with the body’s endocrine system”—yet no scientific oversight body in the US, Europe or elsewhere has determined that plasticizers adversely impact humans in this way. According to last year’s report from the Centers for Disease Control and Prevention, “[p]hthalates are metabolized and excreted quickly and do not accumulate in the body.” That report echoed the findings in 2004 and 2010 by the Children’s National Medical Center and George Washington University School of Medicine showing no adverse effects in organ or sexual functioning in adolescent children exposed to phthalates as neonates. Another recent study has found that even high exposure levels have shown no effect on the genital development of marmosets—let alone humans.

    That said, because of other, more ambiguous studies of rodents exposed to doses hundreds or even thousands of times higher than what humans encounter, some political bodies have instituted bans or restrictions on some types of phthalates. Regulators have long noted that plasticizers are not all alike. So-called low phthalates—DEHP, BBP, DBP and DIBP—are less stable and release out gasses. Although major science bodies in the US, like CDC, have found low phthalates that are taken into the body are safely metabolized, precautionary fears abound. In the US, current law bans the sale of toys intended for children 12 or younger, or child-care articles for children 3 and under, when they contain more than 0.1 percent of DEHP, DBP and BBP.

    The long-term regulatory fate of what are known as high phthalates such as DINP, DIDP and DPHP is less sure. They have been widely tested. From a chemical perspective, they are tightly bound, more stable and more resilient than low phthalates. Pending the results of an ongoing review at the Consumer Product Safety Commission (CPSC), there now exists a temporary ban on any child-care article that contains more than 0.1 percent of DINP, DIDP or DPHP

    European Union scientists and the Danish Environmental Protection Agency have classified low phthalates as reproductive toxicants based on rodent studies, but have concluded DINP, DIDP, and DPHP are safe as used. Frank Jensen, chief adviser to the Danish EPA's chemical unit, has concluded that DINP is a cost effective, quality substitute for the low molecular weight ones.

    Such distinctions between high and low phthalates are critical for scientists and public health officials but an anathema for activists who brandish a broad, anti-chemical bias. Despite writing an entire chapter on plasticizers in her book, Freinkel demonstrated she did not have even a passing knowledge of the different risk profiles of phthalate plasticizers. Her goal was demonization and not enlightenment, and her unbalanced writing does not encourage more effective, scientifically balanced public policy decisions.

    Restricting specific types of phthalates may yet prove appropriate, but regulators need to assess the chemical that could be used in its place.  Often a substitute chemical has only one virtue—it’s been less studied than the chemical being targeted and therefore is less likely to be publicly vilified by activists. A ban may serve the short-term interests of campaigners, but it may not serve children’s safety or other public health interests. It’s often a vanity victory. Real life goes on, choices are made and consumers are often victimized by politicized reactions to complex science controversies.

    Will the comprehensive Australian review resonate with other regulatory bodies around the world which are facing pressures to institute wholesale bans of industrial chemicals, many with safe risk profiles? The CPSC is currently considering its options. This is a great opportunity to let science drive regulation—and maybe science journalists can discuss this issue with context that such critical decisions warrant.

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    Jon Entine, founding director of the Genetic Literacy Project, is senior fellow at the Center for Health&Risk Communication at George Mason University, and a senior fellow at the Statistical Assessment Service (STATS).

    Comments

    There are links on this same page to two Science2.0 articles on studies that did find risks from phthalates:

    http://www.science20.com/news_articles/phthalates_risk_factor_low_birth_...
    http://www.science20.com/news_releases/common_household_chemical_butyl_b...

    So, glad that's been straightened out!

    I haven't exactly followed the science, but I'm sure I've seen other studies, since at least 2006, that showed phthalates were risky - endocrine analogues, I believe was the issue. I say this because the article above makes it seem like the 'anti-phthalate frenzy' is just a bunch of Playboy Bunnies with homespun, new-age theories.

    (I remember the year because a certain acquaintance of mine objected to a certain longish, rubbery object, which was made with phthalates, and it made me curious enough, the next day, to look it up.)

    (For the record, I'm not claiming they're harmful or otherwise. How would I know?)

    JonEntine
    Actually, I said clearly that there are studies that can be used to reaffirm whatever bias you start with.

    As for the two studies that you cited, it looks like you didn't read them (as they are two dated, marginal studies that do little to challenge the conclusions based on a review of hundreds of studies in the latest Australian determination, or recent reviews of the research literature done by the EU and the Danish EPA.

    As for the two you cited:

    (1) both evaluated low phthalates, which I made a point of saying are more controversial than high ones.
    (2) the first study is an association study evaluating low phthalates--of very little use to scientists. More stringent studies have not shown anything more than a loose association at best
    (3) the second study was on rodents. Researchers have consistently found that the impact on rodents does not translate to humans because of the unique way phthalates are metabolized in humans.

    Again, it's key that scientists stick to the data. And reporters--or random readers--should be cautious about cherry picking individual studies to conform to a predetermined prejudice.
    I freely confess I didn't read the two studies - I only skimmed them enough (10 seconds each) to see whether they suggested risks.

    I am indeed a random reader. But I didn't cherry pick anything - I cited every article I knew of that mentioned phthalates! I gave you the whole cherry tree! I just thought it was amusing to find them on the same page as your article.

    I positively claim I know nothing whatsoever about phthalates, except what some girl told me, which I weight accordingly, and what I've forgotten from something I read (on wikipedia probably) 6 years ago!

    As for prejudices, I admit to being prejudiced against "chemicals," in that all it takes is a bit of a rumor about one to make me doubt it's safe. I think if you have to have a simple instinctive response, that's more adaptive than its opposite. But I'm not so prejudiced that I can't be soothed by a little evidence.

    Gerhard Adam
    According to last year’s report from the Centers for Disease Control and Prevention, “[p]hthalates are metabolized and excreted quickly and do not accumulate in the body.”
    True enough, but the same report also says [in the next paragraph]
    In chronic rodent studies, several of the phthalates produced testicular injury, liver injury, liver cancer, and teratogenicity, but these effects either have not been demonstrated when tested in non-human primates or are yet to be studied.

    ...but in vivo studies did not support phthalates having estrogenic effects (Milligan et al., 1998; Okubo et al., 2003; Parks et al., 2000; Zacharewski et al., 1998); however, not all phthalates and metabolites have been tested.
    I don't know whether phthalates are problematic or not, but according to this report, neither does anyone else with absolute certainty.
    Mundus vult decipi
    JonEntine
    Gerhard,

    I totally agree with you, in principle. No one should give phthalates a pass as an appropriate subject for continued research. My point is the opposite--let's not demonize chemicals based on incomplete research, especially when the research on humans (as the studies I linked in my report and dozens more reviewed by the Australian government) seem to suggest that the key issues found in rodent studies have not been confirmed in human studies. BTW, the quote you use saying "not all phthalates and metabolites have been tested" is based on older summaries of phthalates. All the 9 major phthalates have since been tested, and the concerns are just not there for the high pthalates--which is one of my key points. Different types of phthalates have different effects. While scientists and regulators recognize this and are incorporating it into their regulatory schemes, journalists just don't make those distinctions. They seem to want to pre-decide whether they are pro or anti, which is stupid. Let the evidence drive their analyses, not their biases.
    Gerhard Adam
    Fair enough. 
    Mundus vult decipi
    Why would it be wrong to demonize (or, be wary of) all (especially novel, organic) chemicals until they've been scientifically un-demonized?

    JonEntine
    A bit argumentative are you? Why would anyone want to demonize anything that's been in common use for decades with no persuasive evidence that it creates any problems. You can't ever "prove" something is not harmful. Heck, people die from allergic reactions to common foods all the time. Should we demonize them? What kind of world would live in if we chose to demonize--again your over-heated word--any and everything. Vaccines? Let's ban them because they haven't been scientifically "un-demonized" by some elements of the science community (are you listening Dr. Oz?

    You miss the entire point of the story. We need journalists to approach science issues, like chemical toxicity, with a degree of sophistication--or we will have precautionary freaks trying to demonize their pet peeves--which is what happens when it comes to things like chemicals, shale gas, GM foods, etc. That said, we should always keep an open mind when it comes to any controversial product or substance. Wariness though? I think that's way too paranoid unless there is persuasive scientific evidence to back it up.
    Not argumentative - I meant it as a serious question.

    I didn't specifically mean demonize phthalates. I meant what I said: novel, organic chemicals. All I meant was, why shouldn't we we should err on the side of caution, and not take risks until we know what the risks are? (Thus I'm glad someone's doing these studies. Although, they tend to come a bit after the fact, especially in the realm of chemistry.)

    Wariness though? I think that's way too paranoid unless there is persuasive scientific evidence to back it up.

    I would reverse that. We should be wary until there's scientific evidence that it's "safe." (Safe enough, whatever that means in context.) I think wariness is a perfectly legitimate response to the unknown, even if it isn't the only legitimate response. Society and its institutions need to be wary. (Employing scientists to test stuff is one mechanism for society being wary.) Not shun the new, but look before we leap.

    if we chose to demonize--again your over-heated word--any and everything

    Demonize was your word!

    I didn't actually miss the point of your story. Maybe this would be a good spot to say I agree with your thesis? Yes, so-called science journalists should have a better grip on science generally, and mob rule shouldn't decide what gets shelved or implemented (gawd forbid). But my (mostly snarky) comment didn't address any of that. Really I just thought it was an amusing irony to find those two links on the same page. (Blame the webmaster!) I'm sure I wouldn't have commented at all otherwise.

    This is a well-written piece, Jon, and you make an important point. The "anti-" brigade rarely care about the facts/science, preferring to rely on emotive rhetoric ('Frankenfoods', to point out another important case). When this bleeds over into what masquerades as serious 'science' journalism, we start to have a real problem.

    I work in the plasticizerindustry and I am used to the fight of NGO's against our products. Some not so scientific facts often are ignored:
    * Phthalates are used for more than 50 years now, not 1 incident was reported where a human being was harmed by a phthalate.
    * Even at those humans getting administered the highest dosesof phthalates (blood receivers) no adverse effect have been reported ever.
    Usually my arguments are criticized for being inhumane (for considering humans a kind of guinee pig), but they are true.
    My question to anybody attacking the Phthalates would be: Show me 1 incident where a human being was harmed by the Phthalate. (and please do not argue with the weight increase, usually with kids coming out of a fast food restaurant with a Hamburgerin each hand)

    car2nwallaby
    The effects from endocrine disruptors are most pronounced during critical periods of early development.  In that light, it's interesting that the Australian report notes lower (rat) birth weight due to prenatal DINP exposure.  Combine that with the observational study mentioned above that low birth weight was correlated with higher pthalate levels in humans too, and perhaps there is still some cause for concern, if not demonization.
    Consider the wording of the Australian conclusion: "Current risk estimates do not indicate a health concern from exposure of children to DINP in toys and child-care articles".  That means they don't see cause for concern once children are born, but that does not say anything about the effects on a developing fetus in utero.  It is somewhat strange that prenatal exposure was not addressed in the conclusions, given that they do reference those studies in the body of the report.

    Let's remember both sides can fall into the activism trap.  Just as reports of toxicity can be over-sensationalized, reports of no adverse effects can be over-interpreted as well.

    JonEntine
    ...except there are no studies that suggest that "endocrine disruption" occurs in the development stage. An endocrine EFFECT does not mean that normal functions are disturbed in a way that retards development. That theory has been around for two decades and it just hasn't proved out in studies, except when chemicals are fed to rodents in ways that bypass the liver, which renders DINP (and I would even bet more controversial phthalates) harmless. So...we have evidence of incredibly minor effects but as yet no evidence of adverse effects. There have literally been hundreds of tests in this area. There is no new science here. You can try to twist the Australian review to mean something that it doesn't, but it's clear that this review (and similar reviews in the EU) do not suggest adverse effects from DINP. To suggest anything different is irresponsibly playing the "precautionary" card outside of what the evidence suggests.
    car2nwallaby
    I would call reduced birth weight an adverse effect.  You're absolutely correct that the review does not suggest toxicity.  But nor does it confirm the complete absence of adverse effects, particularly for fetal exposure.  Toxicology studies look for obvious physical abnormalities or sickness, but there can be more subtle effects that would not show up in the studies.  For example, obesogenicity might not be detected until later, and subtle cognitive effects might not be evident in lab animals.
    If your argument is that there is not enough evidence to ban DINP, I think I would agree with you.  What I'm suggesting is that there isn't yet enough evidence to say it's completely harmless, either.

    JonEntine
    Agreed.