TIP #132-B Plug in Midgee Repellent, even on Inverter, Toxicology Reports.

Submitted: Wednesday, Nov 22, 2006 at 04:10
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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..


2.1.1 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.

Rat >10,000 mg/kg b.w.

Rat >10,000 mg/kg b.w.

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

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...

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...
"The Last Stand In Open Country"

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Reply By: Andy1 - Wednesday, Nov 22, 2006 at 16:09

Wednesday, Nov 22, 2006 at 16:09

I have followed this midgee thread with a passing interest on the assumption that most people used these plug-in systems, Coles & Woolworths have stocked them for years. Why anyone would even condider a "midgee screen" is beyond me.

Living in the tropics it seems that one developes a minor immunity to the little b's but southern visitors often react badly. When Jude's mother comes to stay we have to use a plug unit in her bedroom at night although our daughter uses this room most of the time & never gets bitten.

In bad sandfly/mosquito areas we just pop in a plug & never a problem! Just a side comment, I read somewhere that if you use one in an enclosed area with a gold fish bowl in the vicinity the fish may go belly up. Us red wine consumers consider ourselves immune to this problem!

AnswerID: 569804

Follow Up By: Bushtracker - Wednesday, Nov 22, 2006 at 17:46

Wednesday, Nov 22, 2006 at 17:46
Thank you for the Positive Feedback Andy. I appreciate the support.

In truth, while I have seen the plug ins myself, I think many of us are a bit Phobic over chemical enhancements into our enviornment, due to the increasing rates of Cancer. Over 20 years of casual medical studies myself, I know that the immune systems response to genetic mutation and damage, is the key; when the immune system becomes overloaded. This is the result of many factors of course: Genetic predisposition inherited, Stress accumulated, dietary and excercise related, and ALSO enviornmental toxins introduced through the food-air-water. So, I am one of those that is a bit Phobic of this kind of thing. HOWEVER, we do have some long term studies out now, that I have breifly touched on above, and so I might even pick one up one of the plugs myself.

For some reason, Richard indicates it is a repellent, not just a killer... They just do not come in. I have been using kerosene lamps with Citronella for years, and that burning of hydrocarbons is probably many times of a toxic smog causing potential damage as these plug ins... I may have converted myself...!!!

Probably my best action is to properly sterilize myself with copious amounts of Shiraz, preferably from McClaren Vale.. Ha!

Best Regards from the Ranger
"The Last Stand In Open Country"

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Follow Up By: Bushtracker - Wednesday, Nov 22, 2006 at 20:00

Wednesday, Nov 22, 2006 at 20:00
Oh, Andy, I neglected to answer you on the question about Gel or AGM.... For two years now we have combined both and had our batteries built for us, with absolutely remarkable results in service... It is German A-200 Gel Hybrid AGM (absorbed glass mat). What it means is the glass mat pads the plates and holds the electrolyte gel. But they have performed admirably...

They are the most cost effective choice right now at about $150 cheaper per battery than the German Gel, at $250 over the counter for our 100 AH. Regards, Ranger
"The Last Stand In Open Country"

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Reply By: Luvntravln - Wednesday, Nov 22, 2006 at 19:11

Wednesday, Nov 22, 2006 at 19:11
Okey Dokey

Mortein plug:

12V version was used extensively in the cruising community when we crossed the Pacific in '92.

For the BT:

1. Are those using Mortein using a 240 or 12V version?

2. How many plugs, e.g,, 1 in the center or 1 at each end?

While I am strongly leaning towards the midgee screens (about $250 for a complete set) this is a much better solution if it really works!

Regarding Steve's information pertaining to Avon, Skin-So-Soft was a staple in the cruising community - forgot all about it (senior moment) - it is being ordered!

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Follow Up By: Bushtracker - Wednesday, Nov 22, 2006 at 19:40

Wednesday, Nov 22, 2006 at 19:40
Check out the label of the one you get, 12v or 240v, they put an effective distance on them. I think one said 7.5 Metres or something.. But knowing you Jay, you are going to buy two anyway. So either store the second one as a back up, or put one each end, whatever you need..

Yea, I know, I am making too much sense again, %&#@! Ha! Ranger
"The Last Stand In Open Country"

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Reply By: Richard - Thursday, Nov 23, 2006 at 05:05

Thursday, Nov 23, 2006 at 05:05
Hi to All,
Thanks Steve for all the research that you did, (some of the research that you showed me is in your opening page).
For many years now I have used the Mortein plug in Mozzie, Midgee, repellent I wish to point out that after spending a lot of time cruising during the past 25 years and mostly in warm tropical areas, I found that this method very effective of keeping the bities from being a real problem in some of the best anchorages you could ever find, it's simple and very effective at little cost. I only used it if bities were a problem. There is no smell or noise and very effective within a minute or two, even works better if you can close windows and put the air conditioning on at the same time.
Having experienced the amount of restriction that the Midgee screens reduce the air into the van after recently I witnessing a comparitive airflow test, I would never consider them, I have enough problem as it is with my travelling partner Dawn and her hot flushes, frequently in need of more air flow in the van than available and wanting everything wide open and a fan or aircon if the air is a little warm or a little still.
The Mortein plug in unit is cheap, 240V pluges into an outlet, purchased with a packet of blue cards, just have to slide one into the middle of the unit, a card lasts me for one night. Draws very little power consumption from my inverter. Much cheaper than chips today and worth every cent, I wouldn't go away in the van without it.


AnswerID: 569806

Follow Up By: Bushtracker - Thursday, Nov 23, 2006 at 17:34

Thursday, Nov 23, 2006 at 17:34
Thank you for taking the time Richard.... What a great report.

I think I am converted myself, why not.... As it is, I shine my LED reading lights up on the ceiling for about 15 minutes, to attract any Mozzies that get into the van, and they I hunt them down like Ming the Merciless... Ha! This would be easier.

Chemical concerns? Well I think the report shows nil affect.. Certainly better than the diseases spread by Mozzies on the overall effect on health and well-being. Ross River Fever not the least of.. Way up in the top end you even have a chance of bloody Malaria. Next time I notice them in a store, I think I will pick on two myself... Midgees, a nuisance, but Mozzies because of the disease they carry feasting on you when you are asleep, makes this a worthwhile venture for me..

Regards, Ranger
"The Last Stand In Open Country"

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Reply By: Fosssil - Thursday, Nov 23, 2006 at 21:29

Thursday, Nov 23, 2006 at 21:29
I think the cost of a pad used to work out at 50c each.(no idea now)..which is not a lot, but when we use them we use only 1/2 a pad and that works fine in a large room so would work well in a van...The 1/2 pad also works for just as long.
I modified the unit so I could just place the 1/2 pad on the heater element and remove it easily otherwise they get stuck...I still have an older modified unit that must be over 10 years old...I used a heated old knife to melt and slice the plastic cover away...the units get quite warm, but not a burn danger.
The best pads were those that Mortein had some years ago...They used to kill the insects..today seem to repel them, but today still work well..(scratching deep in my memory now)...Don't get the pads with a scent as this can be overpowering...especially in a confined space.
I had already decided to use these instead of Midgee screen when we get going...
AnswerID: 569807

Follow Up By: Bushtracker - Friday, Nov 24, 2006 at 22:07

Friday, Nov 24, 2006 at 22:07
Hello Foss,
Good luck clearing up your health issues so you can happily join us Boggers on the road...

And no worries about how long it has taken... You are not even in the running for the "Years in Planning" award. That was taken out by a Gentlemen Ian "Tex" J***** who I think took 5 years at about 75 years of age. He was one of those that took planning to the enth degree!! Out happily now with his truck and van ...

And the top age bracket is held by a Gentleman of 82 years of age, who had the best attitude in History, when he proclaimed with pride at 82 : "Yea, I am going to do this Bushtracker thing for the next ten years, AND THEN find something else to do".... He holds the record for age and attitude we should all try an emulate!!! I'm in training for that!

Regards, Ranger
"The Last Stand In Open Country"

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Follow Up By: Fosssil - Friday, Nov 24, 2006 at 23:24

Friday, Nov 24, 2006 at 23:24
Yep Steve,
We'll be there when and as soon as possible...
Just drew up a revised plan the other day...realised a house on wheels was not needed...lol
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