• Link to SK Organic Resources
  • Weeds Can Be Managed Without Chemical Pesticides
  • Driving Near Recently Sprayed Fields Exposes People to Pesticides
  • Learn About Colony Collapse Disorder and How to Protect Bees
  • Grow a Lush Garden Organically
  • LIving Near Fields Increases Pesticide Exposure
  • Learn About Pesticides in Foods
  • Learn to Keep Insects Out of your Crops
  • Learn to Manage Pests Naturally
  • SNAP Tour of Organic Vegetable Garden

Pyrethrins and Pyrethroids

 also look at exposure, cardiovascular, nervous system effectsrespiratorywildlife, terrestrial invertebrates and pyrethrins, petsresistance, Legislation/Regulatory/Europe, children, Legal/Litigation 

Pyrethrins are one class of insecticides. They are often marketed as "natural" and as "coming from the pyrethrum daisy". This is false. Pyrethrum is the chemical extracted from the pyrethrum daisy. It is not effective for very long so, to make this class of pesticides more effective and last longer, the pesticide industry has chemically produced synthetic pyrethrins, also called pyrethroids. All are toxic to the nervous system. They are known to trigger allergies. Several (alllethrin, bigentrhin, cypermethrin, lambda-cyalothrin, permethrin, resmethrin, sumithrin) have been recognized by the scientific community as endocrine-disruptors. They are also noted as accumulating in sediments in streams and water bodies, often at levels that kill all insects and other invertebrates living in sediments.

SNAP does not consider synthetic pyrethrins as green or reduced-risk products.

Permethrin  General Fact Sheet (NPIC- National Pesticide Information Center 2009) (USA) Even though it's an older fact sheet, it points to toxicity to fish and aquatic organisms, low degradation in indoor environments, and symptoms in animals and people.

Study Confirms Children’s Exposure to Mosquito Pesticides Increases Risk of Respiratory Disease    (Beyond Pesticides, March 3, 2022) Children’s exposure to synthetic pyrethroid insecticides, particularly during the course of mosquito control operations, is associated with increased occurrence of certain respiratory diseases and allergic outcomes, finds research published in the journal Thorax late last month. High levels of metabolites from the fungicide mancozeb are correlated with increased incidence of lower respiratory tract infections. However, synthetic pyrethroid insecticides are the primary offenders, associated with higher odds of current asthma, ever being diagnosed with asthma, recent lower respiratory tract infections, and cough. The strongest association between pyrethroids and adverse health impacts is for wheeze. Increased exposure exhibits stronger correlations, with each 10x increase showing a greater likelihood of developing asthma, wheeze, lower respiratory tract infections, and itchy rash.  SNAP Comment: Synthetic pyrethroids, especially permethrin and pyrethrin are currently the most commonly used insecticide by consumers (respectively 281 and 335 domestic products) other than the imidacloprid used for fleas and ticks for pets. They are in most insect dusts as well as sprayable products like Raid and flea/tick collars. Pyrethroid poisoning is also the most commonly reported form of poisoning at the U.S.Poison control Center. 

Household Pesticide Use Harms Infant Motor Skill Development   (Beyond Pesticides, January 5, 2022) Household pesticide use is associated with harmful impacts to infant motor development, according to a study published late last year in the journal Paediatric and Perinatal Epidemiology. As with other pollutants in society, low-income, people of color communities are disproportionately in contact with toxic pesticides, resulting in exposures that can start early, and affect health over the course of one’s lifetime. '“In adjusted models, infants whose mothers reported household use of rodent or insect pesticides had 1.30 (95% CI 1.05, 1.61) times higher expected gross motor scores than infants in households with no reported household pesticide use, with higher scores indicating decreasing gross motor performance,” the study indicates. Household pesticide use over the last decade has generally shifted away from the use of older organophosphate chemistries to the use of synthetic pyrethroid insecticides. But this switch has not resulted in safer exposures; a growing body of literature is finding that synthetic pyrethroids can cause a range of adverse health impacts, particularly in children.'

Pesticide Use on Island Resorts Tied to Biodiversity Collapse    (Beyond Pesticides, December 8, 2021) . Oceanic islands, despite their small size, harbor 20% of all species, and 50% of endangered species, making conservation critically important in the context of a sixth mass extinction and insect apocalypse.    Results show that, compared to uninhabited islands, urban islands contain roughly half the number of species, while tourist islands contain approximately one third. On urban islands, researchers attribute the disparity to habitat fragmentation, loss of habitat quality, and loss of natural vegetation cover.    With increased occurrences of cosmetic landscaping, small gardens, golf courses, and other tourism-related activities, researchers thus attribute pesticide use as the driver of declines on tourist areas. Every tourist island studied indicates that they regularly apply insecticides, specifically synthetic pyrethroids like deltamethrin, in and around structures to manage common pests like mosquitoes, bedbugs, and cockroaches. 

Deer Ticks Developing Resistance to Popular Tick Control Chemical: Implications of Lyme Disease   (Beyond Pesticides, July 22, 2021) A new study published in the Journal of Medical Entomology finds black-legged ticks (Ixodes scapulari) in New York are developing potential resistance to widely used tick-control pyrethroid insecticide, permethrin.

Disease Carrying Mosquitoes Developing Resistance to Widely Used Mosquito Control Pesticides   (Beyond Pesticides, July 1, 2021) Yellow fever mosquitoes (Aedes aegypti) are evolving resistance to the pyrethroid insecticide permethrin, according to a study published by Colorado State University, highlighting the need to adopt ecologically-based mosquito management. Widespread, intensive use of the pesticide in mosquito control has allowed genetic mutations to persist among these mosquito populations, causing subsequent resistance to permethrin.  Insecticide resistance has been an issue since the introduction of DDT (dichlorodiphenyltrichloroethane) in the 1940s.

Despite 1,700 Dog and Cat Deaths from Flea Collars, EPA Silent; Children at Risk   (Beyond Pesticides, March 5, 2021) Pet owners will be alarmed to read the report, by USA Today, that a popular flea and tick collar — Seresto, developed by Bayer and sold by Elanco — has been linked to nearly 1,700 pet deaths, injuries to tens of thousands of animals, and harm to hundreds of people... Beyond Pesticides and other advocates have warned of the toxicity of pet pesticide treatments, not only to the animals themselves, but also, to children and other household members. There are nontoxic ways to protect pets from fleas and other pests, and to protect human family members at the same time.    The active pesticide ingredients in the Seresto pet collars are imidacloprid and flumethrin.  The neonicotinoid insecticide imidacloprid is a commonly used pesticide associated with serious health and environmental decline. ... Flumethrin is a chemical in the pyrethroid class of synthetic neurotoxic insecticides, which have been repeatedly linked to neurological issues, such as seizures and learning disabilities in children, and to gastrointestinal distress, as well as to damage to non-target invertebrates, according to EPA’s own analysis.'   SNAP Comment: There are 99 imidacloprid products registered in Canada as of 23 March 2021, many of them registered for pet treatments. Flumethrin is not and has not bee registered in Canada. The Seresto trademark is not registered in Canada.

Monarch Massacre: Hundreds of Monarch Butterflies Die After Aerial Mosquito Spraying in North Dakota   (Beyond Pesticides, September 2, 2020) It’s being called the Monarch Massacre—hundreds of monarch butterflies found dead after the Vector Control Department of Cass County, North Dakota aerially sprayed the county for mosquito control. This incident occurred during a moment in history that is seeing monarchs at the edge of extinction, with the number of monarch butterflies overwintering in Mexico having declined 53% from last year, according to a count conducted by World Wildlife Fund (WWF) Mexico

University of Iowa research ties pesticides to heart-disease deaths    'We're in some ways ground zero for a lot of these pesticides'      Use Raid anyone? or mosquito coils? clothing or mosquito nets treated with pyrethroids? About synthetic pyrethroids, which have replaced more toxic insecticides on the home and general market. In spite of pyrethroids having been known to cause allergies and a variety of other health problems, widespread contamination,.as well as being the number one group of pesticides reported to the EPA as causing adverse health effects, they are generally considered by regulatory agencies as safe.   '“There is very little out there where people have actually looked at the cardiovascular system as a target of toxicity for these kind of compounds”. This study correlates urine levels with death occurrence. As many more people have heart disease than die from it, the proportion of people affected by pyrethroids is likely a lot more than 'three times more likely to die of cardiovascular disease than those with low or no exposure.'   'New University of Iowa research out this week associates higher exposure to commonly used insecticides — including those in use across Iowa — with an increased risk of death from all causes, specifically cardiovascular disease — even as the market share of that potentially deadly pesticide grows.    That swell in use, according to UI assistant professor of epidemiology and study author Wei Bao, means the rate of deaths related to the chemical exposure likely has increased as well — although he urged more investigation.' see also Study Links Pyrethroid Insecticides to Cardiovascular Disease and Other Health Hazards   (Beyond Pesticides, January 10, 2020) for a more in-depth discussion of evidence and politics. 

Bug Bombs Don’t Work – At All, According to Study  (Beyond Pesticides, January, 30, 2019) '“In a cost-benefit analysis, you’re getting all costs and no benefits,” said Zachary DeVries, PhD, co-author of the study. “Bug bombs are not killing cockroaches; they’re putting pesticides in places where the cockroaches aren’t; they’re not putting pesticides in places where cockroaches are and they’re increasing pesticide levels in the home...Tests conducted one month after the bug bombs were released still showed pesticide residue levels 34% higher levels originally found in resident’s homes”All the fogger products contained pyrethroids. Learn about alternatives to pesticides for cockroach infestations  under Additional info.

Connecticut State Legislature Bans Residential Mosquito Misters (Beyond Pesticides, May 23, 2018) " Many health advocates have expressed concern that these products, able to spray toxic pesticides on a timer at regular intervals, pose a significant risk to pets and children who can be directly in the path of a mister’s spray. The chemicals employed in these machines are often synthetic pyrethroids, which have been linked to a range of human health effects, from early puberty in boys, to behavioral disorderslearning problemsADHD, and certain cancers. Neighbors who do not want to be exposed to these chemicals are also put at risk from pesticide drift." SNAP Comment: There are many kinds of  pyrethrins coming under various names. A quick PMRA label search done on 4 June 2018 indicates 368 pyrethrin products registered in Canada for domestic use (i.e. by consumers) At least 2 of those pyrethrin products  (# 29683 and 28972) are registered for misters. A complete search would have to be made for each registered pyrethroid to understand the extent of the problem in Canada. 

Pyrethroids are everywhere and  more dangerous than you realize (by Shruti Ravindran, The Verge,  Feb 19, 2014, US article)  A specific group of bug-killers, pyrethroids and pyrethrins, have been soaring in popularity in recent years and now account for more than a quarter of the global market.In 2008. (NOTE: For instance Raid contains types of pyrethroids.) The Center for Public Integrity analyzed 90,000 adverse reaction reports and found that health problems linked to pyrethroids had increased 300 times in 10 years. Up to 2/3 of people in studies have pyrethroid breakdown products in their urine. "A regulatory system that utilizes animal studies can't simulate the effect of toxins on children".

EPA Releases Pyrethroid Risk Assessment, Ignores Numerous Health Effects  (Beyond Pesticides, November 16, 2011)  concluding that these pesticides “do not pose risk concerns for children or adults,” ignoring a wealth of independent data that links this class of chemicals to certain cancers, respiratory and reproductive problems, and the onset of insect resistance. The agency may even consider registering additional new uses of these pesticides.

Recent Studies

Research Shows Commonly Used Pesticides Produce Greater Toxic Effect When Mixed
(Beyond Pesticides, August 11, 2011) A combination of eleven different kinds of commonly used pyrethroids were tested on mice in a new study which found that, at real-world exposure levels, the insecticides can produce heightened toxicity that is equal to the sum of each insecticide’s individual effect. The mixture of similar-acting insecticides works by over-stimulating ...

Report Documents Poisonings from New Generation Pesticides (August 4, 2008)  Pyrethrins and pyrethroids were responsible for more than 26 percent of all major and moderate human incidents involving pesticides in the United States in 2007, up from just 15 percent in 1998 — a 67 percent increase.                       

Pyrethroid Pesticide Affects Puberty at Low Levels  (Beyond Pesticides, Sept 22, 2008)      

Pyrethroid Pesticides Found in Homes and Daycare (Beyond Pesticides, November 3, 2008)  Centers 

also see nervous system effects (autism), Health/respiratoryAir Travelwildlife and Pesticide fact sheets on cyfluthrin, cypermethrin, permethrin, pyrethrin, resmethrin, sumithrin and piperonyl botoxide.