You can even try these easy DIY bug repellents , if you're still skeptical! When Marchesky was doing some outdoor chores he applied bug spray to ward off the mosquitos. Since full strength DEET is highly flammable, if an individual exposed to the hazard of electric arc or garment ignition sprayed his or her clothing and there were an accident, there is a significant risk that the clothing will ignite and continue to burn. In this scenario the DEET is serving as a fuel source.
When permethrin is impregnated appropriately in cloths and nets, toxicity fearfulness is minimal [ 52 ]. Although synthetic pyrethroids are utilized worldwide as active ingredients in MRs [ 15 ] due to their relatively low toxicity to mammals [ 53 ], inappropriate application at high doses initiates neurotoxic effects such as tremors, loss of coordination, hyperactivity, paralysis, and an increase in body temperature.
Other side effects include skin and eye irritation, reproductive effects, mutagenicity, alterations in the immune system, etc. Recent studies also showed that some pyrethroids are listed as endocrine disruptors and possible carcinogens [ 53 ] and pyrethroids might cause behavioral and developmental neurotoxicity, with special concern revolving around infants and children, due to their potential exposure during a sensitive neurodevelopmental stage [ 54 ].
More evidence in the recent years indicates that pyrethroid insecticides can reduce sperm count and motility, cause deformity of the sperm head, increase the count of abnormal sperm, damage sperm DNA, induce its aneuploidy rate, affect sex hormone levels, and produce reproductive toxicity [ 55 ].
Moreover, an elevated concentration of transfluthrin in the gaseous phase during the indoor application of an electric vaporizer was detected, but they found inhalation risk of airborne transfluthrin was low. The exposure levels and potential risk of pyrethroids during the applications of other types of commonly used MRs remain unknown [ 53 ]. On the other hand, long-term exposure to pyrethroid-based MRs in indoor environments causes chronic neurotoxicity, for example, dysfunction of blood-brain barrier permeability, oxidative damage to the brain, [ 56 ] and cholinergic dysfunction which cause learning and memory deficiencies [ 57 ].
No reported toxicity has been made so far against IR , and it induces less irritation to mucous membranes and exhibits safer oral and dermal toxicity than DEET which makes it an attractive alternative to DEET in disease-inflicted endemic regions [ 13 ]. The ester structure of the propionate grants essential advantages because of a short metabolic degradation and quick excretion as a simple water-soluble acid [ 58 ].
Picaridin has the advantage of being odorless and non-sticky or greasy. Moreover, unlike DEET, picaridin does not damage plastics and synthetics. In some studies, picaridin induces no adverse toxic reactions in animal studies but exhibits low toxicity and less dermatologic and olfactory irritant in other studies. DEPA does not show cytotoxicity or mutagenicity [ 59 ], thereby increasing its suitability in direct skin application. Acute and subacute inhalation toxicity studies of DEPA have also been reported [ 61 ] which indicate its applicability as aerosol formulations.
Indalone was an early synthetic repellent effective against both mosquitoes and ticks. It was even more effective than DEET; however, its chronic exposure induced kidney and liver damage in rodents which restricted its application [ 13 ]. EA does not damage synthetic fabrics, plastics, and painted and varnished surfaces which further widen the utility of EA in bed nets, cloths, and different surfaces in the endemic settings [ 14 , 66 ]. Because many conventional pesticide products fall into disfavor with the public, botanical-based pesticides should become an increasingly popular choice as repellents.
There is a perception that natural products are safer for skin application and for the environment, just because they are natural and used for a long time compared to synthetic non-biodegradable products [ 14 ]. In contrast to DEET, some natural repellents are safer than others, and plant-based repellents do not have this strictly tested safety evidence, and many botanical repellents have compounds that need to be used with caution [ 39 ]. PMD has no or very little toxicity to the environment and poses no risks to humans and animals.
PMD has been developed and registered for use against public health pests and is available as a spray and lotion. PMD is the only plant-based repellent that has been advocated for use in disease-endemic areas by the Centers for Disease Control CDC , due to its proven clinical efficacy to prevent malaria, and is considered to pose no risk to human health [ 39 ]. PMD provides excellent safety profile with minimal toxicity. In studies using laboratory animals, PMD demonstrated no adverse effects apart from eye irritation.
It is safe for both children and adults as the toxicity of PMD is very low. However, the label indicates it should not be used on children under the age of 3 [ 7 ]. The safety of neem is extensively reviewed; azadirachtin is nontoxic to mammals and did not show chronic toxicity. Even at high concentrations, neem products were neither mutagenic nor carcinogenic, and they did not produce any skin irritations or organic alterations in mice and rats.
On the other hand, reversible reproduction disturbances could occur due to the daily feeding of aqueous leaf extract for 6 and 9 weeks led to infertility of rats at Using unprocessed and aqueous neem-based products should be encouraged if applied with care. The pure compound azadirachtin, the unprocessed materials, the aqueous extracts, and the seed oil are safe to use even as insecticides to protect stored food for human consumption, whereas nonaqueous extracts turn out to be relatively toxic [ 8 ].
From the ecological and environmental standpoint, azadirachtin is safe and nontoxic to fish, natural enemies, pollinators, birds, and other wildlife. Azadirachtin is classified by the US EPA as class IV practically nontoxic [ 7 , 8 , 17 ] as azadirachtin breaks down within 50— h in water and is degraded by sunlight as the half-life of azadirachtin is only 1 day, leaving no residues.
Safety and advantages of EOs are widely discussed [ 7 , 8 , 17 , 39 ]. There is a popular belief that EOs are benign and harmless to the user. Honestly, increasing the concentration of plant EOs as repellents could increase efficacy, but high concentrations may also cause contact dermatitis. Some of the purified terpenoid ingredients of EOs are moderately toxic to mammals.
Because of their volatility, EOs have limited persistence under field conditions. With few exceptions, the oils themselves or products based on them are mostly nontoxic to mammals, birds, and fish. Moreover, EOs are usually devoid of long-term genotoxic risks, and some of them show a very clear antimutagenic capacity which could be linked to an anticarcinogenic activity. Due to the capacity of EOs to interfere with mitochondrial functions, they may add prooxidant effects and thus become genuine antitumor agents.
The cytotoxic capacity of the essential oils, based on a prooxidant activity, can make them outstanding antiseptic and antimicrobial agents for personal uses, that is, for purifying air, personal hygiene, or even internal use via oral consumption and for insecticidal use for the preservation of crops or food stocks. Some EOs acquired through diet are actually beneficial to human health [ 68 , 69 ].
Eugenol is an eye and skin irritant and has been shown to be mutagenic and tumorigenic. Citronellol and 2-phenylethanol are skin irritants, and 2-phenylethanol is an eye irritant, mutagen, and tumorigenic; they also affect the reproductive and central nervous systems [ 30 ]. Although EOs are exempt from registration through the US EPA, they can be irritating to the skin, and their repellent effect is variable, dependent on formulation and concentration.
The previously mentioned safety and advantages designate that EOs could find their way from the traditional into the modern medical, insecticidal, and repellent domain. Several diseases transmitted by mosquitoes cause high losses of human and animal lives every year.
Unfortunately, the widespread use and effectiveness of commercial formulations containing DEET and other synthetic substances could lead to resistance [ 70 , 71 ]. Some health and environmental concerns lead to the search for natural alternative repellents. The use of repellent plants has been used since antiquity [ 1 ], and it is the only effective protection available for the poor people against vectors and their associated diseases [ 71 ]. Ethnobotanical experience is passed on orally from one generation to another, but it needs to be preserved in a written form and utilized as a rich source of botanicals in repellent bioassays.
Then again, the growing demand for natural repellents points up the further necessity to evaluate new plant-based products critically for personal protection against mosquitoes and mosquito-borne diseases [ 7 , 8 , 17 , 18 ]. Regarding environmental and health concerns, plant-based repellents are better than synthetic molecules. Even though many promising plant repellents are available, their use is still limited; therefore, advance understanding of the chemical ecology of pests and the mode of repellency would be helpful for identifying competitor semiochemicals that could be incorporated into attractant or repellent formulations.
There are numerous commercially available formulations enhancing the longevity of repellent, by controlling the rate of delivery and the rate of evaporation. Such formulations are very useful to people living in the endemic areas in the form of sprays, creams, lotions, aerosols, oils, evaporators, patch, canister, protective clothing, insecticide-treated clothing, and insecticide-treated bed nets [ 7 , 8 , 17 ].
The potential uses and benefits of microencapsulation and nanotechnology are enormous including enhancement involving nanocapsules for pest management and nanosensors for pest detection [ 7 , 8 ].
Nanoparticles are effectively used to control larvae [ 72 , 73 , 74 , 75 , 76 ] and to repel adults of mosquitoes [ 77 , 78 ]. Polymer-based formulations allow entrapping active ingredients and provide release control. Such techniques, applied in topical formulations, fabric modification for personal protection, or food packaging, have been proven to be more effective in increasing repellency time and also in reducing drug dermal absorption, improving safety profiles of these products.
In this work, the main synthetic and natural insect repellents are described as well as their polymeric carrier systems and their potential applications [ 79 ]. Encapsulated EO nanoemulsion is prepared to create stable droplets to increase the retention of the oil and slow down release.
Apply and re-apply a repellent according to the label instructions. Don't overuse the products, but be sure to apply the amount of repellent indicated by the label.
If you don't follow the label directions, the product may not be as effective as you expect. The label on the insect repellent product is your guide to using these products safely and effectively.
The effectiveness of the product can vary due to conditions such as:. Skip to main content. Cyfluthrin and the Environment Cyfluthrin is harmful to aquatic invertebrates, fish, and honeybees. Permethrin and Health Permethrin is linked to neurotoxicity, which acts on sodium ion channels, causing repeated nerve impulses. At high levels, it can affect the function of chloride channels, which may result in seizures. One study found that permethrin and DEET, either in combination or alone, were linked to the death of neural cells in various parts of the brain which may lead to many physiological and behavioral issues, including problems with motor skills, learning and memory.
Another study found that newborn exposure to permethrin impaired working memory by interfering with neural processing in the frontal lobe of the brain. Permethrin and the Environment Permethrin is toxic to fish, aquatic life, and bees. Pyrethroids Pyrethroids are the most common chemical class for bug repellent chemicals. This class contains over 1, insecticides, including:.
Pyrethroids and Health Pyrethroids are lipophilic, which means they love fat cells. They can easily cross the blood-brain-barrier and can thus become toxic to the central nervous system; the WHO has said that synthetic pyrethroids are neuropoisons. Acute reactions to pyrethroids include dermatitis and asthma-like reactions, nausea, incoordination, and burning and itching sensations.
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