Ozone As Pesticide

Makarand writes "Purdue University researchers in the search for alternatives to insect fumigants that damage Earth's ozone layer have found that ozone gas can be used as a potent pesticide without causing any environmental harm. Farmers could use ozone generators to get rid of insects in their grain bins by releasing ozone in them."

Comments

Smog?

[Fjornir]

But the process won't add to the ground-level ozone that is a component of smog, they said. Maier said Purdue's ozone insecticide process uses such low concentrations of ozone that it rapidly dissipates. It would not add to ground-level ozone, which is a component of smog, he said. Can anyone clarify this reasoning? It seems to me that if a lot of farmers were using this that the 'low concentrations' at each location would add up. Yes, I know, that's only a thought experiment, but...

Re:Smog?

[jensend]

IIRC, it wouldn't add up- it would break down. Ozone is not the stablest form of oxygen, after all. If quantities are small enough it will combine with other materials in the air or break down to O2+O. I've got a "Ionic Breeze" air purifier from Sharper Image, and it manifests this behavior- if the quantity of ozone it's put out into an area is small, the ozone doesn't build up and you can have it running indefinitely without any trouble even if you don't have much air circulation. If you have it putting out a fair bit for a while, though, it gets to the point where it's created an environment in which the ozone concentration is high enough that it doesn't break down. Then it gets quite smelly really quickly.

Near Ground Ozone _IS_ an environmental problem.

[VenTatsu]

Ozone produced near the ground does not rise into the upper atmosphere to add to the ozone layer. It will sit near the ground and if the area has weak wind currents (like many vally areas) it will stay in that area and become air polution. LA is notable as an area that has significant ozone polution.

Re:Ozone gas - Toxic?

[moonbender]

That's correct, but the amount used here is not near enough to be toxic. However, during the summer months we routinely have smog alarms around here which caution folks to go outside for prolonged times, mostly due to the ozone in the air. It's, of course, not concentrated so high that it would kill you, but things such as severe headaches are typical issues. Note that the article states that the ozone used as a pesticide would not contribute to the overall smog problem - or at least not significantly, I think the article is not absolutely clear on that.

That reminds me

[joelt49]

this reminds me of a story I saw once on 20/20 about a type of machine that released small amounts of ozone, trying to help people with asthma. Unfortunately, it only aggravated the symptoms. So, I see big lawsuits coming from farmers with asthma. Although the article claims it won't cause environmental damage, who knows. If it stays around, though, it might just sit there, and no further treatements will be necessary. We'll just have to wait and see what happens.

Ozone a great pesticide, but be careful

[CraigoFL]

I recently bought a house with a pool. While reading up on pool maintenance at this excellent site I came across this interesting page on using ozone instead of chlorine as a pool cleaner. Apparently it works very well at killing bacteria and other contaminents, but it is very expensive and very unstable. Most states don't even allow you to use it as a primary sanitizer for your pool.

Ozone might be effective and more environmentally friendly, but it might be too expensive or dangerous for widespread use. Of course, farm work has never been especially cheap or safe... this is just one aspect out of many.

Re:Ozone gas - Toxic?

[inertia187]

If you read the article, you'd know that they intend to use the ozone gas in closed bins that store the grain.

So, they want to use ozone in a closed environment, but if this is possible, what's the harm of using CFCs in a closed environment?

CFCs are great because they act like water (as a solvent) in many ways, but have none of the harmful effects on electronic components. You can completely submerge a PC in CFCs and turn it on, without shorting anything out.

Industry used CFCs for a long time until it was linked to environmental issues. Yes, they were also used as propellents in aerosols, but why did industry drop CFCs from closed environments? They feared leakage.

So, somehow a farm's grain bin is better at keeping ozone out of the environment...go figure.

The grain will burn!

[melted]

Ozone is also a much better oxidant than O2. Gotta be VERY careful with that grain, a bunch of it can just burn at a smallest spark. The environment at the grain elevators also becomes much more explosive. Right now it's prohibited to smoke or create any open fire on the facilities there. Why? Because flour (it's not really flour, but microscopic particles of wheat) suspended in the air is highly explosive. Now imagine this air has high ozone content. Also, there always WILL be leaks from grain storage and ozone is poisonous.

I didn't know this was new...

[Blondie-Wan]

Several years ago I was a laborer at the NCO Club at Eglin AFB, Florida, and we once brought in some ozone generators specifically for pest control. I don't know how common the practice is, but it's definitely been done before.

Is the discovery that it can be used directly around foodstuffs what makes it news? I didn't even know that was a big deal, but now that I think about it, I don't recall us using those generators in the kitchen.

Ozone is highly toxic to humans

[dpbsmith]

The article says "It isn't clear how the ozone kills the insects," but apparently it does, and apparently in low concentrations. We are told that it "uses such low concentrations of ozone that it rapidly dissipates. It would not add to ground-level ozone." Ah, that word "dissipates." But as Barry Commoner reminded us, "everything must go someplace." "Dissipation" isn't the same as vanishing!

And generally speaking things that kill one kind of life (e.g. insects) are hazardous to others (e.g. humans).

See this factsheet, which notes, in part:

HAZARDOUS SUBSTANCE FACT SHEET
Common Name: OZONE
CAS Number: 10028-15-6
DOT Number: None

* Ozone can affect you when breathed in.

* Ozone may cause mutations. Handle with extreme caution.

* Ozone can cause reproductive damage. Handle with extreme caution

* Repeated exposure can cause lung damage.

* ODOR THRESHOLD = 0.045 ppm.

* The range of accepted odor threshold values is quite broad. Caution should be used in relying on odor alone as a warning of potentially hazardous exposures.

WORKPLACE EXPOSURE LIMITS

OSHA: The legal airborne permissible exposure limit

(PEL) is 0.1 ppm averaged over an 8-hour workshift.

NIOSH: The recommended airborne exposure limit is 0.1 ppm which should not be exceeded at any time.

ACGIH: The recommended airborne exposure limit is 0.1 ppm averaged over an 8-hour workshift.

Ozone also gives a nice mellow high

[MarvinMouse]

Having worked around tesla coils and other equipment that creates/gives off a lot of ozone, I can tell you, if you are going to die some way, this is probably one of the best.

You get very very high if the concentration of ozone in the air gets too high. It's a very mellow high as well.

I don't know how dangerous to your brain it is though. It hasn't caused any major problems for me yet. But around electrical equipment that gives off sparks, it's really easy to get a build up of ozone gas, or as we call it at work, happy gas. :-)

Plus ozone definitely has a distinct smell, I find.

Just some interesting tips.

Yes though, ozone is deadly, and I am not recommending "recreational" use of ozone. I have to inhale it, you don't.