Last week, California Environmental Protection Agency (CalEPA) and the Department of Pesticide Regulation (DPR) published its Air Monitoring Network Results for 2017 and found that chlorpyrifos monitored at four different sites throughout California never exceeded any screening level or regulatory target.  However, CalEPA and DPR are currently allowing the Scientific Review Panel on Toxic Air Contaminants (a group of appointed professionals) to finalize its Toxic Air Contaminant Evaluation of Chlorpyrifos which relies solely on scenarios based on devised assumptions that when plugged into models produce potentially unacceptable risk which then requires further mitigation.

Assumptions, Assumptions…

In 2013, DPR contracted with the National Academy of Sciences (NAS) to conduct an independent peer review of DPR’s risk assessment practices.  The National Research Council (NRC) of the NAS completed its review and issued a report in April 2015 with recommendations to improve DPR’s risk assessment process.  One of the findings was that “DPR makes a number of conservative assumptions and decisions in the performance of its risk assessments.  The conflation of a series of conservative assumptions and estimates regarding health effects thresholds and exposure and the application of uncertainty factors can result in scenarios that are well in excess of worst-case exposure…There appears to be a tendency for that to occur in the DPR assessments…”  As a result of that finding, DPR concurred with the NRC’s recommendation to require a relevance review in areas of the risk assessments that are vulnerable to assumption strings.  However, in the case of the Toxic Air Contaminant Evaluation of Chlorpyrifos, there does not seem to be any kind of relevance review here.  Indeed, the report relies on several unrealistic and extreme exposure scenarios – such as a child directly downwind of an application of chlorpyrifos every day for 21 days.  This type of scenario has absolutely no chance of occurring.  California has the most restrictive environmental regulations in the world and existing safety limits already ensure safe use of chlorpyrifos (as well as many other pesticides).

Sound Science

Extensive studies show that current uses of chlorpyrifos meet the U.S. regulatory standard of a reasonable certainty of no harm for humans, including children.

  • Using new and more credible science, the Environmental Protection Agency revised its risk assessment and confirmed that there is no causal link between chlorpyrifos and health problems;
  • Based on safety assurances, chlorpyrifos has been approved for use in more than 100 countries around the globe to protect more than 50 different crops;

Save Our Citrus

California citrus is an extremely valuable commodity currently threatened by an insect-vectored bacterial disease huanglongbing (HLB) or also known as citrus greening.  HLB is vectored by the Asian citrus psyllid (ACP).  Chlorpyrifos has been an important insecticide in the Integrated Pest Management (IPM) systems for ACP due to its efficacy, value as resistance management tool, established international registration status (MRLs), and as a tool against invasive pests and endemic pest outbreaks.

Chlorpyrifos is a critical tool for growers of over 50 different types of crops in the United States and is one of the most widely used active ingredients in insecticides in the world.  Since it was first registered in the United States in 1965, chlorpyrifos has played a key role in pest management efforts, protecting crops against damage caused by a wide range of insect pests in the United States and around the world.

We are confident that authorized uses of chlorpyrifos products, when used as directed, offer wide margins of protection for human health and safety.

DPR is setting a dangerous precedent by ignoring the overwhelming body of scientific evidence and pandering to activist demands.  Chlorpyrifos is the target today and if activists are successful, what will the next target be?