Nathan Rhodes-Zambrana, MPH
Logistics and Safety Coordinator
Before eating a snack, taking medication, or applying bug repellent, most of us check the label. It’s human nature to want to know what we’re putting into or onto our bodies. So, when a plane makes a low pass in our neighborhood performing a mosquito control treatment, we often wonder “What is being sprayed?” That question often leads us straight to Google, searching for the product’s chemical name, its label, and the Safety Data Sheet (SDS). We approach this information with the same mindset we use when checking nutrition facts on a bag of chips, looking for clarity and reassurance. But there’s an important distinction. Reading a chip label tells us exactly what we’ll be ingesting. Reading a pesticide label or SDS, however, doesn’t mean that the public will experience the same level of exposure or risk as someone who handles and applies the product. Yet, it’s easy for our minds to treat those two scenarios as equal, even when they are not.
What is a Chemical Label, and Who Is It For?
Every mosquito control product used by Collier Mosquito Control District (CMCD) comes with an Environmental Protection Agency (EPA)-registered label. This label is a legal document that all pesticide applicators are required to follow. Although written for licensed professionals, the label is publicly available for anyone to read (EPA, 2015). They include important information such as how much of the product to use, where and when it can be applied, what protective equipment is required, and under what conditions it should be handled. At CMCD, we adhere to these instructions precisely. They are not simply guidelines, they are the law, designed to protect our applicators, the environment, and the community we serve (EPA, 2015).
Understanding the Safety Data Sheet (SDS)
Alongside every mosquito control product is a Safety Data Sheet (SDS), which provides detailed safety information such as occupational health and environmental hazards, chemical properties, first aid guidance, and safe handling procedures (OSHA, 2012). The SDS documents are designed for emergency responders, occupational health professionals, and licensed applicators. Their purpose is to ensure the people working directly with the material have all the information they need to do so safely, especially in the event of an accidental spill, occupational exposure, or adverse incident. Because of that, the information often describes worst-case scenarios that could happen if someone were to handle the material incorrectly or without protection. In the controlled, regulated way we use these products, the public is not exposed to those types of risks.
What This Means for the Public
If you’ve ever read a chemical label or SDS and felt concerned, you’re not alone, it’s natural to wonder about safety. But it’s also important to remember that the public is not exposed to these products in the same way a pesticide handler or applicator is. Our professionals receive annual training, maintain state licenses and continuing education, and wear protective gear because they handle the products directly and therefore face a higher level of exposure (OSHA, 2012). The average resident, by contrast, is not likely to come into direct contact with these materials. Products are applied in precise amounts, under the right environmental conditions, and with safeguards in place to protect public health (Fishel, 2012).
Clearing Up Common Misconceptions
One of the biggest misconceptions we encounter is that if a label or SDS lists an occupational health hazard, then the product must be dangerous to anyone nearby. In reality, these documents are written for the people who mix, load, and apply the product – essentially, workers who handle it in a concentrated form and have a much higher level of exposure than the average resident (EPA, 2015). Another misconception is that protective suits, respirators and other personal protective equipment (PPE) are worn because the product is dangerous to everyone. In reality, PPE is required only for workers who handle these materials directly and regularly (OSHA, 2012). The SDS is about their exposure, not yours.
When used properly, mosquito control products are not considered a significant health risk to the public. In fact, multiple independent studies have consistently shown that potential risks are far below the levels of concern set by the EPA (CDC, 2005; Peterson et al, 2006; Duprey et al, 2008; Schleier et al, 2009; Macedo et al, 2010; Preftakes et al, 2011; Schleier et al, 2016; Mendoza et al, 2023; Tia et al, 2025). To date, no negative health effects have been linked to mosquito control operations, whether applied from the ground or the air using ultra-low volume (ULV) techniques.
Let’s Talk About Naled
In 2020, the EPA completed a draft human health risk assessment of naled, the active ingredient in Dibrom Concentrate. Using agricultural models, the assessment noted a temporary potential risk immediately after mosquito control applications (EPA, 2021). However, because naled breaks down very quickly once released, potential residues are expected to decline to levels of no concern within just minutes to a few hours (5 minutes to 3.4 hours) (EPA, 2021). The exact timeframe depends on conditions such as the amount applied, release height, droplet size, and wind speed.
It is important to recognize that mosquito control applications differ greatly from agricultural uses (Mendoza et al, 2023). Since agricultural modeling was applied to this assessment, the risks are expected to be overestimated. Encouragingly, new studies are now underway that focus specifically on mosquito control practices. These modeling studies will allow the EPA to update its pesticide review methodology for mosquito control applications, giving us a clearer picture of actual exposure levels in communities.
In the meantime, we continue to take extra precautions to reduce potential risks. We use application rates below the label’s minimum recommended dose, apply materials at night when people are less likely to be outdoors, and rely on specialized equipment that produces ultra-fine droplets designed to stay airborne and target mosquitoes. These measures mean that potential risks (if any) in our operations are expected to be at the very lowest end of the EPA’s estimated timeframe.
Your Peace of Mind Is Built into the Process
Safety is built into every step of our Integrated Mosquito Management practices. Our goal is for residents to feel confident, not concerned, when they see mosquito control in action. The label and SDS are tools we use to handle products responsibly. They are not warnings aimed at the public. We are proud to operate with transparency and hold ourselves to the highest safety standards because your health matters. So, when you see or hear one of our aircraft fly by, you can rest assured that it is applied with precision, effectiveness, and a clear purpose.
At CMCD, transparency is one of our core values. We openly share information about every control material we use by posting it on our website, and we provide advance notice before all adulticide applications. This allows residents who want to learn more or who prefer to take extra precautions the opportunity to do so. Our goal is to keep you informed, empowered, and confident in the steps we take to protect public health and comfort in Collier County.
To sign up for advance treatment notifications, please visit our website here: https://cmcd.org/treatment-notifications/
To learn more about our control materials, please visit our website here: https://cmcd.org/science/history/control-materials/
To learn more about the registration process for EPA-registered products, please visit: https://www.epa.gov/pesticide-reevaluation/registration-review-process
*PLEASE NOTE*: If you believe you’ve been exposed to a pesticide or are experiencing symptoms of pesticide poisoning, take action immediately. Call 911 for emergencies or contact the Florida Poison Information Center at 1-800-222-1222 for expert guidance. For more information on pesticide poisoning, please visit: https://www.floridahealth.gov/environmental-health/pesticide-poisoning/index.html
References
Centers for Disease Control and Prevention [CDC]. 2005. Human exposure to mosquito-control pesticides – Mississippi, North Carolina, and Virginia, 2002 and 2003. Morb. Mortal. Wkly. Rep. 54: 529–532.
Duprey Z, Rivers S, Luber G, Becker A, Blackmore C. Barr D, Weerasekera G, Kieszak S, Flanders WD, Rubin C. (2008) Community aerial mosquito control and naled exposure. J Am Mosq Control Assoc. 24: 42-6.
Environmental Protection Agency [EPA]. 2015. Introduction to Pesticide Labels. Accessed: August 11, 2025. Website: https://www.epa.gov/pesticide-labels/introduction-pesticide-labels
Environmental Protection Agency [EPA]. 2021. Naled for Mosquito Control. Accessed: August 11, 2025. Website: https://www.epa.gov/mosquitocontrol/naled-mosquito-control
Fishel FM. 2012. Applying Pesticides in Compliance with the National Pollutant Discharge Elimination System (NPDES): Gainesville: University of Florida Institute of Food and Agricultural Sciences. https://edis.ifas.ufl.edu/publication/PI239
Macedo PA, Schleier JJ III, Reed M, Kelly K, Goodman GW, Brown DA, Peterson RKD. 2010. Evaluation of efficacy and human health risk of aerial ultra-low volume applications of pyrethrins and piperonyl butoxide for adult mosquito management in response to West Nile virus activity in Sacramento County, California. J Am Mosq Control Assoc. 26: 57-66.
Mendoza DL, Peterson RKD, Bonds JAS, White GS, Faraji A. 2023. Are adult mosquito control products (adulticides) harmful? A review of the potential human health impacts from exposure to naled and dichlorvos (DDVP). Pollutants. 3: 603-615.
Occupational Safety and Health Administration [OSHA]. 2012. Hazard Communication Standard: Safety Data Sheets. Available at: https://www.osha.gov/sites/default/files/publications/OSHA3514.pdf
Peterson RKD, Macedo PA, Davis RS. 2006. A human-health risk assessment for West Nile virus and insecticides used in mosquito management. Environ Health Perspect. 114: 366-372.
Preftakes CJ, Schleier JJ III, Peterson RKD. 2011. Bystander Exposure to Ultra-Low-Volume Insecticide Applications Used for Adult Mosquito Management. Int J Environ Res Public Health. 8: 2141-2152.
Schleier JJ III, Macedo PA, Davis RS, Shama LM, Peterson RKD. 2009. A two-dimensional probabilistic acute human-health risk assessment of insecticide exposure after adult mosquito management. Stoch. Environ. Res. Risk Assess. 23: 555–563.
Schleier JJ III, Marshall LA, Davis RS, Peterson RKD. 2015. A quantitative approach for integrating multiple lines of evidence for the evaluation of environmental health risks. PeerJ. e730.
Tia Z, Connelly CR, Lange SK, Foley N, Rivera JDL, Lazano S, Nett RJ. 2025. A scoping review to determine if adverse human health effects are associated with use of organophosphates for mosquito control. J Med Entomol. 62:8-18.
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Nathan Rhodes-Zambrana is the Logistics and Safety Coordinator at Collier Mosquito Control District. He holds a Master of Public Health from the University of Miami and is pursuing a Graduate Certificate in Emergency Management from New York Medical College. With a strong background in occupational health and safety, he ensures full compliance with pesticide-use regulations and implements safety protocols that exceed industry standards, fostering a safe and secure workplace at CMCD.
