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...

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.

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.

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.