Pesticides are applied intentionally to the environment by people for the purpose of improving environmental quality for humans, domesticated animals, and plants. Despite the fears and real problems they create, pesticides are partly responsible for the physical well-being enjoyed by most people all over the world.
In particular, pesticides are credited for making an important contribution to making food production more efficient. For example, in 1850 each U.S. farmer produced enough food and fiber for himself and three other people. By the year 2000, each farmer was producing enough food and fiber for more than 135 people, thanks in large part to pesticides. Nonetheless, all is not good with pesticides today.
Concerns about the environment:
First, as pesticides continue to become more prevalent in society, and we become more dependent on them, there are rising concerns about their impacts to the environment.
Second, the quality of our environment is a major issue today, and with that there is increasing urgency to protect the nation’s air, soil, water, beneficial insects, and wildlife, including endangered species.
Third, some pesticides can be persistent within the environment where they can become biologically concentrated. When this happens, the pesticide can become more concentrated in organisms higher up the food chain and cause serious problems. For example, DDT (Dichloro Diphenyl Trichloroethane) is an insecticide with low mammalian toxicity and regarded as safe to use. DDT was widely used insecticide until 1972 when it was banned by the US Environmental Protection Agency (EPA) because it formed biological concentrations in species higher up in the food chain, like the bald eagle.
Are pesticides safe for the environment?
A majority of pesticides are synthetic having been developed in a laboratory, and thereafter carefully vetted by the EPA, and several other regulators, for safety to humans, the environment, and wildlife before being launched.
Thus, before a pesticide comes to market it must go through several years of detailed testing and evaluation to ensure that the pesticide is safe for humans, the environment, and wildlife species. For a pesticide to be considered safe it must pose little or no threat to humans, the environment, and wildlife.
Upon registration, the pesticide is re-evaluated by the US EPA throughout its life to determine whether it continues to be safe to use or poses a threat to humans, the environment, or wildlife species. I other words, a pesticide may be considered safe today but after a few years of use, some new information about its toxicity may lead to its withdrawal from the market by the manufacturer or outright ban by the US EPA.
However, there is one group of pesticide products that is not synthesized in the lab and is considered to be an environmentally safe pesticide product. For example, limonene.
What is Limonene?
- Limonene is a colorless liquid aliphatic hydrocarbon classified as cyclic monoterpene and is a major component in the oil of citrus fruit peels.
- Terpenes are thought to be produced by plants to deter predators and protect plants form pests.
- Limonene was initially known for its capacity to improve the penetration of skincare products.
- This knowledge was used to improve transdermal drug delivery since it was determined that limonene helped reduce skin barrier resistance with low irritancy potential compared to other drug delivery systems.
- Limonene uses include:
- Cosmetics and skincare formulations.
- Food additive to improve scent and taste.
- Natural insect repellent formulations.
- Penetration enhancer.
- Antioxidant.
- Limonene has two isomers: d-limonene and l-limonene.
- D-limonene:
- The principal component of the essential oils present in the rind of citrus fruits, such as orange, lemon, mandarin, grapefruit, and lime.
- A colorless oil that is sparingly soluble in water, has a sweet orange smell, and is widely used in the cosmetics industry.
- Commercially, it is mostly obtained from waste orange peels.
- Recent developments show great potential for this by-product of the citrus industry as an innovative green chemical for a variety of uses.
- Rapidly Expanding Applications of Limonene
- D-limonene:
- Gulf of Mexico’s Deepwater Horizon oil spill of 2011 – a formulation of d-limonene and surfactant was used to degrease and clean vessels and equipment with encrusted heavy oil.
- Used to improve yields in petroleum extraction (separation) from oil sands.
- D-limonene can be conveniently mixed with surfactants to form environmentally friendly water-based formulations. These formulations have low concentrations of volatile organic compounds that are suitable for treating contaminated surfaces in many industrial environments.
- D-limonene can be used as a bio-based solvent, a green alternative to petroleum-based solvents.
- In 1950, Henry Schulz created the first large volume market for d-limonene, thereby commercializing the isomer as a versatile solvent alternative to toxic solvents that were obtained from fossil fuels.
- L-limonene:
- Least abundant of the essential oils present in the rind of citrus fruits.
- Has a turpentine smell.
- Also found in plants as the major component of volatiles emitted by oaks and pines.
Limonene as a pest control agent
Limonene was first registered as an insecticide in the US in 1958, and later as an antimicrobial agent in 1971.
- Limonene was the first natural pesticide ingredient used in environmentally-friendly pest control.
- Limonene has low oral and dermal toxicity to mammals, birds, and fish.
- Limonene does not harm or repel honey bees.
- Today, pesticide products containing limonene are used for flea and tick control on pets, insecticidal sprays, mosquito larvicides, and insect repellents.
Limonene as an aid to pest control
Limonene can be used as an adjuvant. For example Brewer International’s Cide Kick™ and Cide Kick II™ both of which are formulated with limonene.
Cide Kick™ and Cide Kick II™:
- Formulated with 100% d’limonene.
- Nonionic surfactants.
- Act as a combined wetting agent, activator, and penetrant.
- Helps herbicide uptake by breaking down the waxy cuticles on leaf surfaces and penetration of the bud and bark area.
- Compatible with most aquatic and terrestrial herbicides, insecticides, and other pesticides.
- Labeled uses include:
- In low volume basal applications in brush control.
- In the agriculture, citrus, and turf industries for weed control or invasive plant species control.
- In forest site preparation.
- In utility rights-of-way and roadside vegetation management.
- In aquatic systems for control of surface and submerged plants.
- To achieve the best control of invasive plants when using Cide Kick™, make sure you read the herbicide label and follow all recommendations.
- Insecticidal properties – When Cide Kick™ was applied alone on collards and tomato, a high level of control of silverleaf whitefly (74%) was reported.
The future for Limonene
As the demand for limonene-based products continues to increase, wider application in agriculture, aquatic and terrestrial vegetation, and management of invasive species in rights of way and forestry is anticipated. Why? Because limonene is safe for humans, the environment, and wildlife.
Please visit https://brewerint.com for more information on limonene-based products.
References
- Ciriminna R., M. Lomeli-Rodriguez, P.D. Carà, J.A. Lopez-Sanchez, M. Pagliaro. 2014. Limonene: a versatile chemical of the bioeconomy. Chemical Comm. https://pubs.rsc.org/en/content/articlelanding/2014/cc/c4cc06147k (Accessed, Oct. 25, 2021).
- Florida Citrus Hall of Fame. 2007. Dr. Henry E. ‘Bert’ Schulz (1921 – 2009). https://floridacitrushalloffame.com/inductees/henry-e-bert-schulz/ (Accessed, Oct. 25, 2021).
- Hollingsworth, R.G. 2005. Limonene, a citrus extract, for control of mealy bugs and scale insects. J. Econ, Entomol. 98(3): 772-779 (Accessed, Oct. 25, 2021).
- Liu, T., and P.A. Stansly. 2000. Insecticidal Activity of Surfactants and Oils Against Silverleaf Whitefly (Bemisia argentifolii) Nymphs (Homoptera: Aleyrodidae) on Collards and Tomato. https://swfrec.ifas.ufl.edu/docs/pdf/entomology/publications/ref_0037.pdf (Accessed, Oct. 25, 2021).
- US EPA Fact Sheet for Limonene. 1994. https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_PC-079701_1-Sep-94.pdf (Accessed, Oct. 25, 2021).
Brewer International (https://brewerint.com/) has been a leader in land and water chemistry since the 1980’s and for over 40 years has proudly served it’s national and regional distributors.
Our products are used widely across the United States in agriculture, aquatics, forestry, rights of way, and land management.
Our customers trust our dedication to quality ingredients, tried and true formulas, and positive outcomes.
