Well Courtesy of Richard Tal*****, he came back in this afternoon and we reviewed the Mortein plug in module again.. It is about half the size of a tennis ball, a warmer with plug in wafers. He reports that it is nearly 100% effective, even against mozzies. For your benefit, I researched the chemicals on the Internet. For those of you that cannot do this, I am putting on two of the clearest reports here for you. I am suitably impressed with the results. The first is a private Research Firm, the second is by the U.N. Health Organisation. It is definitely worth considering, certainly better than cutting off air flow with midgee screens. For any that want to read, here are some summary studies. Typically medical reports are a bit long, I have just put in the highlight section on mamallian toxicology. If you are concerned it is worth reading... You may just want to skim through it, as I have put a summary at the end worth noting.
Part 1: A brief excerpt on the first of the two Chemicals… Allethrin…
Allethrin Fact Sheet
ThermaCELL Mosquito Repellent uses a repellent known as allethrin. Below is information on this repellent.
What is Allethrin?
Allethrin is a synthetic analog (chemical copy) of a naturally occurring insecticide, pyrethrin, found in the pyrethum flower, a member of the chrysanthemum family.
How effective is Allethrin?
• Mosquitoes, Sand flies and No-See-Ums: up to 98% effective. Protection is greatest at 7.5 ft (15 ft diameter) and closer to the unit.
• Black Flies: up to 79% protection. Protection is greatest 3.75 ft (7 feet in diameter) from the unit. Testing was done in windy conditions. In no-wind conditions, the protection level would most likely have been higher.
Are there any health risks?
ThermaCELL Mosquito Repellent has sold hundreds of thousands of units and over a million refills. No health problems have been reported to the company.
What happens when Allethrin is left outside?
Allethrin, a pyrethroid, will after time in an indoor or outdoor situation be biodegraded by the environment. The longevity of allethrin in the environment varies from 1-2 hours in the atmosphere to less than 8 hours in an aqueous environment or on a glass plate under sunlamps. Allethrin will be broken down into water, CO2, and other carbon based materials. Allethrin when stored in a laboratory or manufacturing setting, can be stored at room temperature, in a dark container with no contact with strong oxidizers. Allethrin in an outdoor environment will biodegrade in a relatively short time and is not considered a persistent pesticide. Allethrin is known as a “knock-down,” quick-acting pesticide but has no residual activity because of its short half-life in the environment.
Is Allethrin safe to use around adults and children?
• Studies have been conducted on the affects of allethrin. One such study was done by Toxicologist Anne Costello*.
• When ThermaCELL is used outdoors as directed, the risk of exposure is significantly decreased due to naturally occurring air movement.
• When people are exposed to allethrin by inhalation or touch, it is metabolized (or digested) very quickly. Allethrin does not “accumulate” in or stay in people’s bodies.
• The study concluded that, even under these “worst case scenario” conditions, ThermaCELL does not pose an unreasonable risk to humans (Adults or Children) because the exposure level is 2000 to 3000 times less than the No Observable Effect Level (NOEL) for allethrin. NOEL is the highest dosage given to an animal that does not cause any significant health effects.
*Anne Costello is a research scientist and toxicologist with over 20 years of experience. She holds a degree in toxicology from Philadelphia College of Pharmacy and Science. Prior to working at Scientific Coordination, Ms. Costello had the responsibility for toxicology data supporting more than 400 product labels of the OFF® and Raid® product lines of S.C. Johnson Wax. As a research scientist for SC Johnson Wax, Inc., Ms Costello designed, monitored, and interpreted toxicology studies for technical and formulated pesticide products. She was very instrumental in the research and toxicology data prepared for the registration of the SCJ product OFF Skintastic.® She also designed and conducted risk assessments to evaluate potential toxicity hazards related to numerous products under development.
Part 2, Excerpt from United Nations Study on the other Chemical: Phenothrin..
2.1 TOXICOLOGY - MAMMALS
2.1.1 Absorption route: Absorbed from the gastrointestinal
tract and from the intact skin. The dermal absorption rate differs
between the (1R)- cis - and the (1R)- trans -isomers. No data are
available for the rate or extent of absorption from the lung.
2.1.2 Mode of action: d-Phenothrin is a neuropoison.
The symptoms of poisoning are typical of those of pyrethroids without
a cyano-substituent. The proposed mechanism of action is due to the
reversible binding of d-phenothrin to the sodium channels of the
neuronal membrane, in this way modifying the permeability of the
membrane to ions.
2.1.3 Excretion products: No published data are
available for the combined isomers of d-phenothrin. The metabolism
of the individual (1R)- cis - and (1R)- trans - isomers has been
investigated in the rat. For both isomers an oral dose of 10 mg/kg
b.w. was metabolized by hydrolysis, oxidation and conjugation and 96%
of the administered dose was recovered in the urine and faeces within
six days.
Following oral administration of the (1R)- trans - isomer, the urine
was the major excretory route. The isomer was extensively
metabolized to oxidative and conjugated derivatives of the hydrolysed
ester. Oxidative and conjugated derivatives of the
(1R)- cis -isomer were also observed but hydrolysis of the ester
linkage was a minor metabolic pathway. With this isomer the faeces
was the major excretory route.
The metabolic profiles were similar following dermal application,
although the rates of excretion for each isomer showed some
differences between the two routes of administration.
2.1.4 Toxicity, single dose:
Oral LD50
Rat >10,000 mg/kg b.w. (without vehicle)
Rat > 5,000 mg/kg b.w.
Mouse > 5,000 mg/kg b.w. (in corn oil)
Dermal LD50
Rat >10,000 mg/kg b.w.
Intraperitoneal LD50
Rat > 5,000 mg/kg b.w.
Mouse > 5,000 mg/kg b.w.
Intravenous LD50
Rat 452-492 mg/kg b.w.
Mouse 354-405 mg/kg b.w.
LD50(1R)-phenothrin
Oral
Rat >10,000 mg/kg b.w.
Dermal
Rat >10,000 mg/kg b.w.
Subcutaneous
Rat >10,000 mg/kg b.w.
Inhalation LC50 - 4 hour exposure (1R)-phenothrin
Rat >3.76 g/m3
Mouse >1.2 g m3 (1-2 µm particulates in kerosene)
No sex difference in the toxicity was reported. Following
intravenous administration symptoms of poisoning included
fibrillation, tremor, slow respiration, salivation, lacrimation,
ataxia and paralysis. The symptoms appeared 0.5 - 1 hour after
administration and diminished spontaneously.
No histopathological findings in the nervous system were observed
following four hour inhalation exposure of rats to 3.76 mg/L (see
Section 2.1.7).
2.1.5 Toxicity, repeated dose:
Inhalation: Sprague Dawley rats or ddY mice exposed to
concentrations of less than 0.21 mg (1R)-phenothrin/L, for 4
hours/day, five days/week for four weeks, showed no adverse effect on
behaviour, growth, clinical chemistry or organ histopathology.
2.1.6 Dietary studies:
Short term: A 24 week dietary administration of up to 2500 mg
(1R)-phenothrin/kg diet to Sprague Dawley rats had no adverse
effect on growth, haematology, biochemical or histopathological
parameters. Doses more than 5000 mg/kg diet produced increased
liver weights which were accompanied by histopathological changes of
an unspecified nature. Rats and dogs receiving (1R)-phenothrin in
the diet for six months showed no adverse effect at 1000 and 300
mg/kg diet, respectively.
Long term: A dose related increased incidence of alveolar
amyloidosis was observed in Swiss mice receiving 300-3000 mg d-
phenothrin/kg diet for 18 months. The increased liver weights (both
sexes) and a decreased growth rate (males) were observed at 3000
mg/kg diet.
No compound-related adverse effects were observed in rats receiving
up to 2000 mg d-phenothrin/kg diet for two years. At 6000 mg/kg
diet, growth was affected in both sexes. Serum glutamate-pyruvate
transferase activity was increased in the males of this dose group.
2.1.7 Supplementary studies of toxicity:
Carcinogenicity: No tumours attributable to d-phenothrin exposure
were observed in Swiss mice following 18 months administration of up
to 3000 mg/kg diet, or in rats receiving less than 6000 mg/kg diet in
the long-term feeding studied described above.
Teratogenicity: No teratogenic effects were observed. The NOELs for
New Zealand white rabbits and mice were 30 and 3000 mg/kg b.w./day
respectively.
Mutagenicity: Two oral doses of 1500 mg/kg b.w./day to male mice
did not induce mutation in a host-mediated assay with Salmonella
typhimurium -G46. Similar investigations with (1R)- trans
-phenothrin (250 mg/kg b.w./day) or (1R)- cis -phenothrin (90 mg/kg
b.w./day) were also negative.
No mutagenic potential was observed with or without metabolic
activation of d-phenothrin, or the individual isomers, in several
strains of S. typhimurium or Escherichia coli . d-Phenothrin
did not induce mutations in Bacillus subtilis . In vivo and
in vitro chromosomal aberration tests showed negative results.
Reproduction: No significant changes in reproductive potential were
observed in a three generation reproduction study on Charles River
rats. The NOEL was 2000 mg/kg diet.
Neurotoxicity: d-Phenothrin at high doses, in common with
pyrethroids of similar chemical structure, may induce ataxia.
Rats receiving oral doses of 5000 mg (1R)-phenothrin/kg b.w./day (as
SumithrinR) for five days showed evidence of poisoning, such as leg
weakness or ataxia, and some died. In survivors three days after
cessation of exposure no clinical signs of poisoning were apparent.
No significant morphological changes were observed.
Other: (1R) - phenothrin had no effect on a variety of in vitro
and in vivo pharmacological parameters. These tests included
hexabarbital sleeping times in mice, body temperature in rats, blood
pressure and heart rate in dogs, and the contractile activity of
various muscle preparation in vitro .
2.1.8 Modifications of toxicity: The geometric
isomers undergo different metabolic pathways (see Section 2.1.3).
The rapid hydrolysis of the trans -isomers and the slower
oxidation of the cis - isomers are similar to that observed with
other pyrethroids. Inhibition of the oxidative enzymes may increase
the toxicity of the cis isomers.
End of Report...
SUMMARY:
These tests are in the hundreds to thousands of times the exposure you would get from the warming wafer in the plug in module. You can research further, but this might be an easy answer. I am favorably impressed. While I still avoid chemicals, a bit of a health nut (except for alcohol, particularly in good aged grape juice of the Shiraz variety about 4 years old) Ha! This little warmer is probably a very good alternative for the few times when you have problem. Certainly HAS to be better than cutting down the air flow…
Kind Regards from the long Ranger, here trying to help...
