Product Code Database
Pesticides are substances that are used to pest control pests. They include , , , , and many others (see table). The most common of these are herbicides, which account for approximately 50% of all pesticide use globally. Most pesticides are used as plant protection products (also known as crop protection products), which in general protect plants from , fungi, or .
In general, a pesticide is a chemical or biological agent (such as a virus, bacterium, or fungus) that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant , weeds, mollusca, , , fish, (roundworms), and that destroy property, cause nuisance, spread disease, or are disease vectors. Pesticides thus increase Crop yield. Along with these benefits, pesticides also have drawbacks, such as potential toxicity to humans and other species.
| Algae |
| Bacteria |
| Fungus and |
| Plant |
| Algae, Bacteria, Fungi, and |
The word pesticide derives from the Latin pestis (plague) and caedere (kill).
The Food and Agriculture Organization (FAO) has defined pesticide as:
according to the EPA include microbial pesticides, biochemical pesticides, and plant-incorporated protectants.
Pesticides can be classified into structural classes, with many structural classes developed for each of the target organisms listed in the table. A structural class is usually associated with a single mode of action, whereas a mode of action may encompass more than one structural class.
The pesticidal chemical (active ingredient) is mixed (formulated) with other components to form the product that is sold, and which is applied in various ways. Pesticides in gas form are Fumigation.
Pesticides can be classified based upon their mode of action, which indicates the exact biological mechanism which the pesticide disrupts. The modes of action are important for resistance management, and are categorized and administered by the insecticide, herbicide, and fungicide resistance action committees.
Pesticides may be systemic or non-systemic. A systemic pesticide moves (translocates) inside the plant. Translocation may be upward in the xylem, or downward in the phloem or both. Non-systemic pesticides (contact pesticides) remain on the surface and act through direct contact with the target organism. Pesticides are more effective if they are systemic. Systemicity is a prerequisite for the pesticide to be used as a seed-treatment.
Pesticides can be classified as persistent (non-biodegradable) or non-persistent (Biodegradation). A pesticide must be persistent enough to kill or control its target but must degrade fast enough not to accumulate in the environment or the Biomagnification in order to be approved by the authorities. Persistent pesticides, including DDT, were banned many years ago, an exception being spraying in houses to combat malaria Vector control.
Resistance to a pesticide was first seen in the 1920s with inorganic pesticides, and later it was found that development of resistance is to be expected, and measures to delay it are important. Integrated pest management (IPM) was introduced in the 1950s. By careful analysis and spraying only when an economical or biological threshold of crop damage is reached, pesticide application is reduced. This became in the 2020s the official policy of international organisations, industry, and many governments. With the introduction of high yielding varieties in the 1960s in the Green Revolution, more pesticides were used. Since the 1980s genetically modified crops were introduced, which resulted in lower amounts of insecticides used on them. Organic farming agriculture, which uses only non-synthetic pesticides, has grown and in 2020 represents about 1.5 per cent of the world's total agricultural land.
Pesticides have become more effective. Application rates fell from 1,000 to 2,500 grams of active ingredient per hectare (g/ha) in the 1950s to 40–100 g/ha in the 2000s. Despite this, amounts used have increased. In high income countries over 20 years between the 1990s and 2010s amounts used increased 20%, while in the low income countries amounts increased 1623%.
The process starts with testing (screening) against target organisms such as Insecticide, Fungicide or Herbicide. Inputs are typically random compounds, , compounds designed to disrupt a biochemical target, compounds described in patents or literature, or Biopesticide organisms.
Compounds that are active in the screening process, known as hits or leads, cannot be used as pesticides, except for biocontrol organisms and some potent natural products. These lead compounds need to be optimised by a series of cycles of synthesis and testing of analogs. For approval by regulatory authorities for use as pesticides, the optimized compounds must meet several requirements. In addition to being potent (low application rate), they must show low toxicity to non-target organisms, low environmental impact, and viable manufacturing cost. The cost of developing a pesticide in 2024 was estimated to be 301 million US dollars. It has become more difficult to find new pesticides. More than 100 new active ingredients were introduced in the 2000s and less than 40 in the 2010s. are cheaper to develop, since the authorities require less toxicological and environmental study. Since 2000 the rate of new biological product introduction has frequently exceeded that of conventional products.
More than 25% of existing chemical pesticides contain one or more chiral centres (stereogenic centres). . Newer pesticides with lower application rates tend to have more complex structures, and thus more often contain chiral centres. In cases when most or all of the pesticidal activity in a new compound is found in one enantiomer (the Eudysmic ratio), the registration and use of the compound as this single enantiomer is preferred. This reduces the total application rate and avoids the tedious environmental testing required when registering a racemate. However, if a viable enantioselective manufacturing route cannot be found, then the Racemic mixture is registered and used.
Integrated pest management, the use of multiple approaches to control pests, is becoming widespread and has been used with success in countries such as Indonesia, China, Bangladesh, the U.S., Australia, and Mexico. IPM attempts to recognize the more widespread impacts of an action on an ecosystem, so that natural balances are not upset. (1998). 9780195100334, Oxford University Press. ISBN 9780195100334
Each use of a pesticide carries some associated risk. Proper pesticide use decreases these associated risks to a level deemed acceptable by pesticide regulatory agencies such as the United States Environmental Protection Agency (EPA) and the Pest Management Regulatory Agency (PMRA) of Canada.
DDT, sprayed on the walls of houses, is an organochlorine that has been used to fight malaria vectors (mosquitos) since the 1940s. The World Health Organization recommend this approach. It and other organochlorine pesticides have been banned in most countries worldwide because of their persistence in the environment and human toxicity. DDT has become less effective, as resistance was identified in Africa as early as 1955, and by 1972 nineteen species of mosquito worldwide were resistant to DDT.
Applications per cropland area in 2021 varied widely, from 10.9 kg/hectare in Brazil to 0.8 kg/ha in the Russian Federation. The level in Brazil was about twice as high as in Argentina (5.6 kg/ha) and Indonesia (5.3 kg/ha). Insecticide use in the US has declined by more than half since 1980 (0.6%/yr), mostly due to the near phase-out of . In corn fields, the decline was even steeper, due to the switchover to transgenic Bt corn.
There are two levels of benefits for pesticide use, primary and secondary. Primary benefits are direct gains from the use of pesticides and secondary benefits are effects that are more long-term.
Controlling human/livestock and nuisance organisms
Controlling organisms that harm other human activities and structures
Occupational use of pesticides may affect health negatively. mimicking hormones causing reproductive problems, and also causing cancer. A 2007 systematic review found that "most studies on non-Hodgkin lymphoma and leukemia showed positive associations with pesticide exposure" and thus concluded that cosmetic use of pesticides should be decreased. There is substantial evidence of associations between organophosphate insecticide exposures and neurobehavioral alterations. Limited evidence also exists for other negative outcomes from pesticide exposure including neurological, birth defects, and fetal death.
2014 epidemiological review found associations between autism and exposure to certain pesticides, but noted that the available evidence was insufficient to conclude that the relationship was causal.
Owing to inadequate regulation and safety precautions, 99% of pesticide-related deaths occur in developing countries that account for only 25% of pesticide usage.
The American Academy of Pediatrics recommends limiting exposure of children to pesticides and using safer alternatives:
One study found pesticide self-poisoning the method of choice in one third of suicides worldwide, and recommended, among other things, more restrictions on the types of pesticides that are most harmful to humans.
Pesticide use is widespread in Latin America, as around US$3 billion are spent each year in the region. Records indicate an increase in the frequency of pesticide poisonings over the past two decades. The most common incidents of pesticide poisoning is thought to result from exposure to organophosphate and carbamate insecticides. At-home pesticide use, use of unregulated products, and the role of undocumented workers within the agricultural industry makes characterizing true pesticide exposure a challenge. It is estimated that 50–80% of pesticide poisoning cases are unreported.
Underreporting of pesticide poisoning is especially common in areas where agricultural workers are less likely to seek care from a healthcare facility that may be monitoring or tracking the incidence of acute poisoning. The extent of unintentional pesticide poisoning may be much greater than available data suggest, particularly among developing countries. Globally, agriculture and food production remain one of the largest industries. In East Africa, the agricultural industry represents one of the largest sectors of the economy, with nearly 80% of its population relying on agriculture for income. Farmers in these communities rely on pesticide products to maintain high crop yields.
Some East Africa governments are shifting to corporate farming, and opportunities for foreign conglomerates to operate commercial farms have led to more accessible research on pesticide use and exposure among workers. In other areas where large proportions of the population rely on subsistence, small-scale farming, estimating pesticide use and exposure is more difficult.
Markers of biological effect provide an estimation of exposure based on cellular activities related to the mechanism of action. For example, many studies investigating exposure to pesticides often involve the quantification of the acetylcholinesterase enzyme at the neural synapse to determine the magnitude of the inhibitory effect of organophosphate and carbamate pesticides.
Another method of quantifying exposure involves measuring, at the molecular level, the amount of pesticide interacting with the site of action. These methods are more commonly used for occupational exposures where the mechanism of action is better understood, as described by WHO guidelines published in "Biological Monitoring of Chemical Exposure in the Workplace".((World Health Organization. Office of Occupational Health.)) (1996). 9789518021585, World Health Organization. . ISBN 9789518021585 Better understanding of how pesticides elicit their toxic effects is needed before this method of exposure assessment can be applied to occupational exposure of agricultural workers.
Alternative methods to assess exposure include questionnaires to discern from participants whether they are experiencing symptoms associated with pesticide poisoning. Self-reported symptoms may include headaches, dizziness, nausea, joint pain, or respiratory symptoms.
While measuring biomarkers or markers of biological effects may provide more accurate estimates of exposure, collecting these data in the field is often impractical and many methods are not sensitive enough to detect low-level concentrations. Rapid cholinesterase test kits exist to collect blood samples in the field. Conducting large scale assessments of agricultural workers in remote regions of developing countries makes the implementation of these kits a challenge. The cholinesterase assay is a useful clinical tool to assess individual exposure and acute toxicity. Considerable variability in baseline enzyme activity among individuals makes it difficult to compare field measurements of cholinesterase activity to a reference dose to determine health risk associated with exposure. Another challenge in deriving a reference dose is identifying health endpoints that are relevant to exposure. More epidemiological research is needed to identify critical health endpoints, particularly among populations who are occupationally exposed.
In addition, pesticide use reduces invertebrate biodiversity in streams, contributes to pollinator decline, destroys habitat (especially for birds), and threatens endangered species. Pests can develop a resistance to the pesticide (pesticide resistance), necessitating a new pesticide. Alternatively a greater dose of the pesticide can be used to counteract the resistance, although this will cause a worsening of the ambient pollution problem.
The Stockholm Convention on Persistent Organic Pollutants banned all persistent pesticides, in particular DDT and other organochlorine pesticides, which were stable and Lipophilicity, and thus able to Bioaccumulation (2025). 9780073524160, McGraw-Hill Companies Inc.. ISBN 9780073524160 in the body and the Biomagnification. and which spread throughout the planet.Pesticide Usage in the United States: History, Benefits, Risks, and Trends; Bulletin 1121, November 2000, K.S. Delaplane, Cooperative Extension Service, The University of Georgia College of Agricultural and Environmental Sciences Persistent pesticides are no longer used for agriculture, and will not be approved by the authorities. Because the half life in soil is long (for DDT 2–15 years) residues can still be detected in humans at levels 5 to 10 times lower than found in the 1970s.
Pesticides now have to be degradable in the environment. Such degradation of pesticides is due to both innate chemical properties of the compounds and environmental processes or conditions. For example, the presence of halogens within a chemical structure often slows down degradation in an aerobic environment. Adsorption to soil may retard pesticide movement, but also may reduce bioavailability to microbial degraders.
Pesticide contamination in the environment can be monitored through such as bee .
| $1.1 billion |
| $1.5 billion |
| $1.4 billion |
| $2.2 billion |
| $2.0 billion |
| $1.4 billion |
| $9.6 billion |
In one study, the human health and environmental costs due to pesticides in the United States was estimated to be $9.6 billion: offset by about $40 billion in increased agricultural production.
Additional costs include the registration process and the cost of purchasing pesticides: which are typically borne by agrichemical companies and farmers respectively. The registration process can take several years to complete (there are 70 types of field tests) and can cost $50–70 million for a single pesticide. At the beginning of the 21st century, the United States spent approximately $10 billion on pesticides annually.
These methods are becoming increasingly popular and often are safer than traditional chemical pesticides. In addition, EPA is registering reduced-risk pesticides in increasing numbers.
Pesticide resistance is increasing and that may make alternatives more attractive.
| Control algae in lakes, canals, swimming pools, water tanks, and other sites | |
| kill birds | |
| Kill or repel organisms that attach to underwater surfaces, such as boat bottoms | |
| Kill microorganisms (such as bacteria and viruses) | |
| Attract pests (for example, to lure an insect or rodent to a trap). | |
| Kill bacteria | |
| Certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals | |
| Kill microorganisms | |
| Cause leaves or foliage to drop from a plant, usually to facilitate harvest. | |
| Promote drying of living tissues, such as unwanted plant tops. | |
| Kill or inactivate disease-producing microorganisms on inanimate objects | |
| Kill fungi (including blights, mildews, molds, and rusts) | |
| Produce gas or vapor intended to destroy pests in buildings or soil | |
| A genetic mechanism embedded into the genetic material of the target species, which can kill or suppress the reproductive of its descendants. | |
| Kill weeds and other plants that grow where they are not wanted | |
| Insect growth regulators | Disrupt the molting, maturing from pupal stage to adult, or other life processes of insects. |
| Kill insects and other arthropods | |
| Kills Lampreys | |
| Kill mites that feed on plants and animals | |
| Microorganisms that kill, inhibit, or out compete pests, including insects or other microorganisms | |
| Kill snails and slugs | |
| Kill nematodes (microscopic, worm-like organisms that feed on plant roots) | |
| Kill eggs of insects and mites | |
| Biochemicals used to disrupt the mating behavior of insects | |
| Piscicide | Kills fish |
| Plant growth regulators | Alter the expected growth, flowering or reproduction rate of plants (does not include fertilizers). |
| Biopesticide | Substances that plants produce from genetic material that has been added to the plant. |
| Repel pests, including insects (such as mosquitoes) and birds | |
| Control mice and other rodents | |
| Kill slime-producing microorganisms such as algae, bacteria, fungi, and | |
| Soil sterilant | Temporarily or permanently prevents the growth of all plants and animals |
| Kills viruses. | |
| Wood preservatives | Used to make wood resistant to insects, fungi, and other pests. |
Worldwide, 85% of countries have pesticide legislation for the proper storage of pesticides and 51% include provisions to ensure proper disposal of all obsolete pesticides.
Though pesticide regulations differ from country to country, pesticides, and products on which they were used are traded across international borders. To deal with inconsistencies in regulations among countries, delegates to a conference of the United Nations Food and Agriculture Organization adopted an International Code of Conduct on the Distribution and Use of Pesticides in 1985 to create voluntary standards of pesticide regulation for many countries. The Code was updated in 1998 and 2002. The FAO claims that the code has raised awareness about pesticide hazards and decreased the number of countries without restrictions on pesticide use.
Three other efforts to improve regulation of international pesticide trade are the United Nations London Guidelines for the Exchange of Information on Chemicals in International Trade and the United Nations Codex Alimentarius Commission. The former seeks to implement procedures for ensuring that prior informed consent exists between countries buying and selling pesticides, while the latter seeks to create uniform standards for maximum levels of pesticide residues among participating countries.
Studies must be conducted to establish the conditions in which the material is safe to use and the effectiveness against the intended pest(s). The EPA regulates pesticides to ensure that these products do not pose adverse effects to humans or the environment, with an emphasis on the health and safety of children. Pesticides produced before November 1984 continue to be reassessed in order to meet the current scientific and regulatory standards. All registered pesticides are reviewed every 15 years to ensure they meet the proper standards. During the registration process, a label is created. The label contains directions for proper use of the material in addition to safety restrictions. Based on acute toxicity, pesticides are assigned to a Toxicity Class. Pesticides are the most thoroughly tested chemicals after drugs in the United States; those used on food require more than 100 tests to determine a range of potential impacts.
Some pesticides are considered too hazardous for sale to the general public and are designated restricted use pesticides. Only certified applicators, who have passed an exam, may purchase or supervise the application of restricted use pesticides. Records of sales and use are required to be maintained and may be audited by government agencies charged with the enforcement of pesticide regulations. These records must be made available to employees and state or territorial environmental regulatory agencies.
In addition to the EPA, the United States Department of Agriculture (USDA) and the United States Food and Drug Administration (FDA) set standards for the level of pesticide residue that is allowed on or in crops. The EPA looks at what the potential human health and environmental effects might be associated with the use of the pesticide.
In addition, the U.S. EPA uses the National Research Council's four-step process for human health risk assessment: (1) Hazard Identification, (2) Dose-Response Assessment, (3) Exposure Assessment, and (4) Risk Characterization.
In 2013 Kaua'i County (Hawaiʻi) passed Bill No. 2491 to add an article to Chapter 22 of the county's code relating to pesticides and GMOs. The bill strengthens protections of local communities in Kaua'i where many large pesticide companies test their products.
The first legislation providing federal authority for regulating pesticides was enacted in 1910.
In 2023 The Environment Committee of European Parliament approved a decision aiming to reduce pesticide use by 50% (the most hazardous by 65%) by the year 2030 and ensure sustainable use of pesticides (for example use them only as a last resort). The decision also includes measures for providing farmers with alternatives.
Persistent pesticides are no longer used for agriculture, and will not be approved by the authorities. Because the half life in soil is long (for DDT 2–15 years) residues can still be detected in humans at levels 5 to 10 times lower than found in the 1970s.
Residues are monitored by the authorities. In 2016, over 99% of samples of US produce had no pesticide residue or had residue levels well below the EPA tolerance levels for each pesticide.
|
|
