Why Didn’t the EPA Ban Clothianidin?

The EPA recently rejected an emergency petition to ban clothianidin due to colony collapse disorder (CCD). The tone of posts and stories about this are that it’s just amazing that the EPA wouldn’t ban clothianidin — it’s a bee-killing pesticide after all! There’s even a petition to ask the EPA to reconsider. An excerpt to give an idea of tone:

Last month, for the second time, the EPA refused to intervene to stop the use of the pesticide clothianidin, which scientists believe is at least partially to blame for the alarming rise in bee colony collapse — the sudden bee die-off which has claimed about 30% of the U.S. honey bee population each year since 2006.

To read this, you would think the EPA are just arbitrarily rejecting good science and public policy, but as usual there’s a bit more to it. I’ll be posting more on this as I read more, but I think a few excerpts from the actual documents the EPA released in the most recent petition rejection are useful. The main response letter is readable, even by non-experts, and makes it clear why an emergency petition was inappropriate.

When can the EPA ban a pesticide before going thru normal cancellation and review procedures?

The EPA response gives their authority here as being an imminent hazard:

The EPA may commence proceedings to suspend the registration of a pesticide during the period necessary to complete cancellation proceedings if it determines that an “imminent hazard” exists from the use of the pesticide.

But what really is an imminent hazard?

Courts addressing the suspension provisions have held that an imminent hazard exists if there is “a substantial likelihood that serious harm will be experienced during the year or two required in any realistic projection of the administrative process”.

Thus, to show imminent hazard, the petitioners would have to show that the harm would very likely occur within two years. The letter goes on to note that other courts have said the harm would have to occur within three or four months.

Why does the EPA reject the petitioners finding of imminent hazard?

The EPA response goes on to note that they do not believe imminent hazard has been demonstrated, saying:

As set forth in the legal background section of this response, and as explained by the federal courts, the imminent hazard standard includes the concept that the harm is imminent; that is, that it must be occurring or likely to occur within the one to two years necessary to complete cancellation proceedings — or in the case of an emergency suspension, within the three to four months necessary to complete suspension proceedings. However, nowhere in the petition do the petitioners explain whether the serious agriculture and ecological harm alleged on page 36 of the petition is likely to occur during these time periods.

So the petitioners failed to provide evidence for one of the conditions the EPA must follow to grant their petition. Worse:

Further the imminent hazard standard also incorporates FIFRA‘s unreasonable adverse effects standard, which is a “risk-benefit” standard. Because petitioners only address the potential harm from the use of clothianidin without addressing whether the harm is unreasonable when weighed against clothianidin’s benefits, the petition also fails to address this threshold matter as well.

The petitioners basically failed to give the EPA what they needed to even try to grant their request. That said, the EPA says they are going to look at it anyway:

Despite the facial inadequacy of petitioners’ imminent hazard claim, given the nature of the harm asserted, the EPA examined the evidence cited by petitioners to determine whether that information demonstrates that there is nonetheless a substantial likelihood of serious imminent harm. Based on the data, literature, and incidents cited in the petition and otherwise available to the Office of Pesticide Programs, the EPA does not find there currently is evidence adequate to demonstrate an imminent and substantial likelihood of serious harm occurring to bees and other pollinators from the use of clothianidin.

The paragraph continues noting:

  • Scientific literature clearly shows clothianidin is acutely toxic
  • Literature shows foraging bees are occasionally harmed by clothianidin
  • Evidence does not suggest severe economic or ecological harm from clothianidin in the next two years.
  • The adverse reactions from clothianidin that do exist should be mitigated.

But is clothianidin strongly linked with bee deaths?

This is a much harder question than it seems. As noted in a previous post there are a lot of questions we have to answer. We can’t just say “kills bees, therefore ban” because by that standard we’d have to ban pretty much all insecticides. The question is whether clothianidin specifically is more harmful or excessively harmful compared to its benefits to human beings. I don’t want to try to answer that here (I have an incredibly long list of posts I want to do if only I have the energy) but let’s see what the EPA said in their response letter1.

The petitioners claim that research indicates that honey bee colonies are in decline recently and that this decline appears to correlate with the registration of clothianidin and other neonicotinoid pesticides.

The EPA then continues noting:

  • Bee colonies have been registered for 20 years but a steady decline has existed for 60 years. In other words, if pesticides are implicated, neonics and clothianidin don’t seem to be uniquely harmful (and pesticides likely are involved in bee declines — as are bee diseases and pests, climate change and habitat loss).
  • More recently, colony losses have declined even though neonics continue to be used at levels at or above how they were used when CCD began in the United States. The EPA notes that this doesn’t mean neonics aren’t involved, just that it suggests it isn’t the primary cause.
  • Much of the literature petitioners cite have unaccounted confounding effects in their experiments, are actually for imidacloprid (also a neonicotinoid) or show effects on individual bees more than effects on colonies.

A major issue that should be determined is how widespread clothianidin use is and whether that itself increases its harmful effects. The EPA discusses this and notes that 90% of corn seed is treated with some neonicotinoid pesticide (I had no idea it was that high!) The petitioners note that clothianidin is persistent, however the EPA counters there is no evidence it persists more than year following planting and that more studies are being done.

While clothianidin is clearly acutely toxic to bees, it is not generally used in a way that causes acute issues. The more relevant question is whether the levels in corn plants and in the environment, as consumed by bees, are similar to those show in sub-lethal dose studies to affect bees. The EPA states:

The levels of clothianidin in pollen and nectar typically seen in the field are, however, generally below the levels at which sublethal effects reportedly happen, and lethal effects occur. Thus, the data do not suggest that bees are being regularly exposed to levels of clothianidin in pollen and nectar that could result in the sort of imminent, population level impacts necessary to support an imminent hazard finding.

But is clothianidin causing colony collapse disorder? That is the fear that many have and if you search the internet, you would think the case is certain. The EPA notes that the cited studies show that in a lab setting imidacloprid seems to show the effects needed for CCD. But the EPA notes:

However, the studies cited do not address whether these effects are permanent or transitory or whether such effects would be likely for other neoniotinoid insecticides. Additionally, the petitioners did not provide any evidence that the laboratory results are reflective of what would occur in the field and if so, whether the degree to which they occur would occur would effect populations of honey bees. For example, the minimum concentrations at which significant biological effects occurred in the majority of the cited studies are not typically present in the field or in chronic concentrations present in nectar and pollen from the most widespread use patterns of clothianidin. In addition, the pesticide residue analyses from national surveys of commercial honey bee colonies indicate that colonies that were eventually determined to have succumbed to CCD did not contain elevated levels of neonicotinoids including clothianidin, nor do colonies in the areas of the U.S. where the most treated corn seed is planted apppear to succumb to CCD at a higher rate than other colonies.

The EPA’s response continues answering various concerns including synergistic effects (the most likely in my mind, but apparently not that cut and dry), specific poisoning incidents (these are almost all acute cases and only total 20 in the united states and weirdly 120 in Canada), and general agricultural losses and ecologic effects. I really recommend reading it. It will only take you twenty minutes and provides good perspective on the limits of action for a regulatory body and how scientific evidence is used by regulators.

So now what?

The EPA has denied this emergency petition, but they are continuing to investigate. Senator Gillibrand has called for an expedited review. All registered pesticides are required to undergo regular re-review to determine if they have excess negative effects as compared to benefits. Obviously there are a lot of pesticides registered, so the EPA does this on a schedule. Since clothianidin isn’t up for re-review until 2018, Senator Gillibrand’s request for an expedited review seems reasonable to me. In fact, the EPA is already doing this review as you’ll note on the EPA’s webpage in the section “Next Regulatory Steps for Clothianidin:

Given the concern about clothianidin and other neonicotinoid pesticides and the EPA’s dedication to pollinator protection, the agency has accelerated the comprehensive re-evaluation of these pesticides in the registration review program. We are coordinating this re-evaluation with California’s Department of Pesticide Regulation and Canada’s Pest Management Regulatory Authority. This extensive review will determine if any restrictions are necessary to protect people, the environment, or pollinators. The EPA’s registration review docket for clothianidin opened in December 2011 (Docket ID: EPA EPA-HQ-OPP-2011-0865). In September 2012, the agency will seek independent scientific peer review on how to better assess the risks of pesticides to pollinators. This effort will improve our understanding and strengthen the scientific and regulatory process to protect honey bees and other pollinators.

Given how much attention is being given to clothianidin and bees, it doesn’t seem like the EPA is acting in a corrupt or incorrect manner. The EPA is obligated by law to make certain determinations based on best evidence before they can act. Asking or requiring them to do otherwise would not be good governance.


  1. Despite the belief of some, regulators working in organizations like the EPA are in general trying to do the right thing. They make mistakes and are sometimes subject to undue pressures, but it’s not like they are cackling viciously in their chairs in Washington thinking up new ways to screw over the environment to the benefit of pesticide makers.

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