Air purifier? - Part 2

[WussRedXLi]

After turning off the prallethrin, how long does it still have the repellent effect?

Seems like most of you turn on when nobody is around so I assume it will still have effect for some time after turning off.

Not sure why the product says turn off still work, it says "Special Remarks: Has a unique vapourising system which protects your family against dengue mosquitos for 30 nights even with open windows despite turning it off."

That means the device is still emitting some vapours probably. It's a liquid?

In that case if there is a baby in the room, it's best that you need to remove the device also.

 

[WussRedXLi]

its the charcoal component that will absorb smell... HEPA doesnt...

The HEPA filter does take on a bit of the smells of the room (somewhat) if there's a long duration + strong smelling thing in the room. It's not chemical adsorption like the AC layer, of course.

 

[WussRedXLi]

Allethrin variants. Supposed to be even more effective.

 

[super365]

Allethrin variants. Supposed to be even more effective.

"supposed more effective"> you tested both Allethrin and Prallethin?

Allethrin also like prallethin safe to humans health correct?

Allethrin is cheaper $6.65 or $7.95 for 60 nights,

Cheaper than Baygon Liquid Electric Repeller 21.9ML $6.40 for 30 nights.

I do not have baby.

 

[WussRedXLi]

Bro super365 asked a good question regarding if Prallethrin (Baygon plug-in vaporiser) is the best. Baygon is using 1.6% Prallethrin. Above d-trans Allethrin is 2% and 2.6% respectively for Shieldtox and Mortein.

This study documented the mortality timings for the mozzies. (ie close door/windows smoke out session)

http://www.icup.org.uk/reports/icup041.pdf

d-allerthrin is at double the concentration of Prallerthrin.

 

[WussRedXLi]

"supposed more effective"> you tested both Allethrin and Prallethin?

Allethrin also like prallethin safe to humans health correct?

Allethrin is cheaper $6.65 or $7.95 for 60 nights,

Cheaper than Baygon Liquid Electric Repeller 21.9ML $6.40 for 30 nights.

I do not have baby.

Just nice....did a quick google and got the scientific test results. Yes, prallethrin apparently has a double knock-out effect.

Costs depends on usage. If it's continuous usage, then yeah. But some may just want to buy 2 units and smoke the %!@#$!@# hell out of room and switch it off. Hence they want FASTEST KNOCKOUT POWER.

Similar to gunning 1/4 can of Baygon into the air for 1 room....not really supposed to do that with aersols as it's a brute force but least effective approach coz aerosolisation is not the same as vapourisation. It'd still work though.

 

[super365]

Just nice....did a quick google and got the scientific test results. Yes, prallethrin apparently has a double knock-out effect.

Costs depends on usage. If it's continuous usage, then yeah. But some may just want to buy 2 units and smoke the %!@#$!@# hell out of room and switch it off. Hence they want FASTEST KNOCKOUT POWER.

Similar to gunning 1/4 can of Baygon into the air for 1 room....not really supposed to do that with aersols as it's a brute force but least effective approach coz aerosolisation is not the same as vapourisation. It'd still work though.

So overall Prallethrin more effective than Allethrin correct?
Baygon plug-in vaporiser (Prallethrin) is better that those Allethrin ones?
The report too technical for me, no simple conclusion.

Do you mean use 2 units together? Turn on 2 at same time?

 

[WussRedXLi]

So overall Prallethrin more effective than Allethrin correct?
Baygon plug-in vaporiser (Prallethrin) is better that those Allethrin ones?
The report too technical for me, no simple conclusion.

Do you mean use 2 units together? Turn on 2 at same time?

Yes, P is more effective than A as an aerial repellent and killing of aedes (if close door/windows condition). Not talking abt costs or other stuff.

But i'm wondering what does Baygon product description mean when they say that it protects XX nights even after switched off. That means it's continuously being used up? ie still vaporising even with no electricity coz the solvents are designed as such, just that if switched on then it's much faster or something?
That makes a difference in cost over a long period of time. Coz basically you cannot store it for next dengue season etc. If you have 3-4 repeller devices, it adds up quickly.


Turn on 2 together. Seriously you'd need a couple of units, coz you want a whole house knock-out. Not only clear 1 room. Coz you'll get bitten again "tomorrow" if the mozzie manages to escape out of the room. Unless if you are sure the mozzie is still in the room and you close doors/windows quickly.

A lot depends on the ground also.....

 

[Gixxerfied]

I have 4 of those baygon repeller in all 4 rms..

4 refills standing by..But cant give a gauge cos MBR one only switch on day time..Studyroom, living rm and one near kitchen only off for 5-6 hours when i reach home..Before going to slp i will switch on, morning wife will switch off since she goes to work earlier than me..Then before i go work i will switch on and off when i'm back from work..

 

[super365]

Yes, P is more effective than A as an aerial repellent and killing of aedes (if close door/windows condition). Not talking abt costs or other stuff.

But i'm wondering what does Baygon product description mean when they say that it protects XX nights even after switched off. That means it's continuously being used up? ie still vaporising even with no electricity coz the solvents are designed as such, just that if switched on then it's much faster or something?
That makes a difference in cost over a long period of time. Coz basically you cannot store it for next dengue season etc. If you have 3-4 repeller devices, it adds up quickly.


Turn on 2 together. Seriously you'd need a couple of units, coz you want a whole house knock-out. Not only clear 1 room. Coz you'll get bitten again "tomorrow" if the mozzie manages to escape out of the room. Unless if you are sure the mozzie is still in the room and you close doors/windows quickly.

A lot depends on the ground also.....

I also not sure what it means, if you never on electricity, does the liquid gets lesser, does it give off smell? Maybe what you think is right, maybe no electricity still vapourising, with electricity stronger or something.

The sentence "Special Remarks: Has a unique vapourising system which protects your family against dengue mosquitos for 30 nights even with open windows despite turning it off." is found in fairprice site http://www.fairprice.com.sg/webapp/...tId=26946&urlRequestType=Base&catalogId=10051

but the box pictures and other sites like never write the sentence.

This site also also never write the sentence http://www.baygon.com.ph/en-ph/products/baygon-anti-dengue-liquid-repeller/tabs/how-to-use

Or maybe you email them ask. I did not see any .com official site.

The box image below says "protection from the moment you turn it on until it is turned off"

 

[kandinsky]

The sentence "Special Remarks: Has a unique vapourising system which protects your family against dengue mosquitos for 30 nights even with open windows despite turning it off." is found in fairprice site http://www.fairprice.com.sg/webapp/...tId=26946&urlRequestType=Base&catalogId=10051

but the box pictures and other sites like never write the sentence.

This site also also never write the sentence http://www.baygon.com.ph/en-ph/products/baygon-anti-dengue-liquid-repeller/tabs/how-to-use

Or maybe you email them ask. I did not see any .com official site.

The box image below says "protection from the moment you turn it on until it is turned off"

Yeah, a simple explanation is that whoever was tasked to upload the description at Fairprice probably paraphrased the text wrongly. It really makes no sense if you think about it. The fact that it contradicts the text on the product itself kinda confirms that.

 

[WussRedXLi]

Then perhaps that is it, error.....

 

[super365]

Turn on 2 together. Seriously you'd need a couple of units, coz you want a whole house knock-out. Not only clear 1 room. Coz you'll get bitten again "tomorrow" if the mozzie manages to escape out of the room. Unless if you are sure the mozzie is still in the room and you close doors/windows quickly.

A lot depends on the ground also.....

I do not understand your meaning written above. I thought when using Prallethrin you should open a gap in the windows so as to let mosquito escape out of the room. (as written in thread #1948)

Not sure what you mean by don't let mosquito escape and close doors/windows when mosquito is in the room, you said
"Coz you'll get bitten again "tomorrow" if the mozzie manages to escape out of the room."
"Unless if you are sure the mozzie is still in the room and you close doors/windows quickly."

Do you mean you close all windows and doors of the room, and turn on the electric Prallethrin repeller so the Parallethrin smell will accumulate and increase more inside the room and all the mosquito in the room smell it and will die inside the room?

Do you all use Parallethrin to make mosquitoes die inside the room or repel it to outside the window?

 

[tildveryn]

Allethrin variants. Supposed to be even more effective.

I have tested all different brands in supermarket including those in the pic.

All didnt manage to repel mosquitoes except Baygon one.... but even for Baygon one, it only works in very small area...

Tested in my service yard for each brand each month since 2 years ago. Mosquitoes can still be found right next to the repellent... hahahahhaha

 

[super365]

I have tested all different brands in supermarket including those in the pic.

All didnt manage to repel mosquitoes except Baygon one.... but even for Baygon one, it only works in very small area...

Tested in my service yard for each brand each month since 2 years ago. Mosquitoes can still be found right next to the repellent... hahahahhaha

Is the electric switched turned on when you found mosquitoes right next to the repellent? Is it the Baygon one?

How small area does it work? Half area of hdb bedroom? One hdb bedroom?

 

[kandinsky]

Do you all use Parallethrin to make mosquitoes die inside the room or repel it to outside the window?

It should be a combination, you can't really control it to the extent where you say you want to use it to repel then it won't go in. Those stubborn that go in, continued exposure, then might die inside lor.

See the second half of the second para. Deterrence from entry > bite inhibition > knock-down > continued exposure = death

via: Mosquitoes and Their Control
https://books.google.com.sg/books?id=JIfgVr1f4IQC&printsec=frontcover#v=onepage&q&f=false

 

[kandinsky]

Mosquitoes can still be found right next to the repellent... hahahahhaha

They have evolved

To be fair, my impression is that vapour is generally fairly weak. It's a compromise at a solution that we humans can tolerate also. To really whack them, still need to spray, which will have a lot more contact/toxicity.

 

[WussRedXLi]

They have evolved

To be fair, my impression is that vapour is generally fairly weak. It's a compromise at a solution that we humans can tolerate also. To really whack them, still need to spray, which will have a lot more contact/toxicity.

That's why i told them in the other (Zika) thread in EDMW that you'd need at least 1 per room. And that's for normal situations. If hotspot, it'd need at least 2 per room. Best is if you can close the windows/doors first to build up the plume.

Some chose to use dried chrysanthemum flowers even, i asked if they know the concentration of the phyrethiod (allethrin) needed to start repelling the mozzies, not even talking about KO or lethal dose. What is the amount/kilograms typically to reach that?

No answer.

In a typical HDB room, unless if you are super duper blocked, a slight wind would just shift that plume and render the repellency property useless. Actually it's reported in quite a number of articles....and on youtube you can search for actual ground test by nature lovers/hikers/campers testing a product called Thermalcell which uses those mosquito mats with allethrin and heated by a small butane burner. Once you are walking (eg 3km/h), the protection is gone.

For us here in the Air Purifier thread (or the 2015 El nino haze thread), of coz we know very well how these concepts of plume/concentration work.

 

[WussRedXLi]

Super365 asked a good question.

That is why i posted in the other thread that you'd need at least 5 units in a typical HDB room, or 1 in every room. ACtually for that, my recommendation is just for repellency, and assuming near windless conditions.


What is the knockout/lethal dosage. Note, from what i read, KO or paralysed can mean mozzies waking up after their enzymes breakdown the chemical. It's just that for us humans, we break this down tens of thousands of times faster.

For children (and tested animals), the effects are there coz kids esp infants cannot break down as fast.


Nothing scientific here but i checked the cans of insecticides. Typically the formulations are multiple ***thrin in various %.

I noted that for Prallerthrin, it's like 0.09%. I believe it's FAIRPRICE brand or something, it has Prallerthrin @ 0.09% but Allethrin @ 0.33%.

Each can of spray is like 500-600ml.

The Shieldtox vaporiser is 2.0% Allethrin, Mortein 2.6% Allethrin (both 45ml, 60 days). Baygon vaporiser 1.6% Prallethrin (21.9ml 30 days). So can say the vaporizing rate is the same, jus volume is diff.

Lets take Mortein at 2.6% allethrin 45ml. Basically it's the same as a can of aerosol bug spray at 0.26% allethrin 450ml contents.
So 1 can you spray for 60 times daily (if used 8-hr for vaporising duration), that works out to be 4.5ml worth of equivalent bug spray insecticide. That's 1 vaporising unit.

However, it is different from bug spray, coz bug spray is sprayed onto surfaces and works via physical contact with ants etc. If you sprayed the bug spray into the air, it's aerosolised or very tiny droplets. It would work for mozzies only if the hanging-effect aerosol (PM50 thereabouts? not sure just guessing) comes into contact with the mozzies. The hang time would not be very much, so that's why the manufacturers does not recommend "spraying into the air" as it's only very effective for a very very short period.

Vaporising is different. The hang time is excellent as it's "pumped directly into the air". I think the heating element really vaporised the allethrin and it's not even PM 0.1. So that "equivalent amount of 4.5ml of bug spray) it rendered more effective. Now, if you use 2 units, that'd be 9ml of bug spray....if you switched it on 8hrs.

Look at those 10ml syringes for an idea of how much liquid 9ml is. I reckon 9ml volume is at least a good 4 seconds continuous blast of blast spray from the aerosol can. It's a very wild guess here, but i believe as a vapour (ie efficient), it should be enough to kill the bugs in the room.

But remember, that's for an airtight room, ie windows have rubber seals cutting out 99% of air leakage even in windy external conditions. So do close your windows in that 8hr stretch with 2 vaporisers, if you are looking for that effect.

 

[WussRedXLi]

I have tested all different brands in supermarket including those in the pic.

All didnt manage to repel mosquitoes except Baygon one.... but even for Baygon one, it only works in very small area...

Tested in my service yard for each brand each month since 2 years ago. Mosquitoes can still be found right next to the repellent... hahahahhaha

Baygon contains Prallethrin, i searched for the study earlier and what it found is that the lethal dose kill time for aedes aegypti (original source is Penang, so shd be directly comparable to ours) is the same as allethrin in the same experiment. But allethrin is at double the concentration.
Baygon is 1.6% Prallethrin. Shieldtox is 2.0% d-trans allethrin, Mortein is 2.6%. So i guess allethrin products might need to be 3.2% to be similar?

Both Shieldtox and Baygon heater seems to be vaporising the same amount of liquid in the containers, 60 days vs 30 days (43ml and 21.9ml respectively)

Anyway, as mentioned, i have posted many times in the EDMW Zika thread that one would need to maintain the plume, so literally no wind conditions are needed. I know, that sort of goes against the recommendation of "Keep the windows open". So, well, i really have no comments on how it'd affect adults over the long run.

The youtube vids also show how it works. I think i'd just post here as well ba........

This Thermalcell uses Allethrin as well.