Can our grill ever be used again after we used wasp spray on it?

July 10, 2013 6:15 AM

Last night, we discovered a wasp's nest in our grill. The grill is connected to our house's natural gas lines so it isn't easily replaced. My wife sprayed the nest with Raid brand wasp and hornet spray. The active ingredients are "Prallethrin" and "Cypermethrin" and the can says the inactive ingredients include petroleum distillates. The can says to wash any food preparation surfaces that get exposed to the spray, but I worry that the grill may be difficult to adequately clean and I don't want my family ingesting dangerous chemicals. Can this grill be used again? Do you have any tips on how we can adequately clean it?
posted by Area Man to Food & Drink (18 answers total)

You could try washing the rack and then baking it in the oven at 500 degrees for an hour. That typically burns off any chemicals.
posted by parmanparman at 6:17 AM on July 10, 2013

I think parmanparman's suggestion is good, but if you're still worried, you may be able to get replacement racks.
posted by nightwood at 6:25 AM on July 10, 2013

Hose it down then crank it up for a bit.
posted by sanka at 6:25 AM on July 10, 2013 [3 favorites]

No reason you can't clean the grill. Just take off the rack, get a hose and a bucket of water, prepare for a dirty job. If you are more concerned, try the suggestion above.

By the way, I usually just dab some grease on the surface where the wasps/hornets built after blasting the nest off with a hose. That may be an old wive's tale but it seems to work for me in preventing them from rebuilding at the same spot, which seems to be what they like to do.
posted by selfnoise at 6:26 AM on July 10, 2013

Instead of baking the rack in the oven after a good scrubbing, how about just turning up the grill itself and letting it bake the rack that way?
posted by easily confused at 6:26 AM on July 10, 2013

Best answer: I would thoroughly wash and scrub the rack. Then, without replacing the rack, run the grill for at least an hour on its highest setting to clean the inside. The petroleum distillates (basically mineral oil) will burn off or vaporize. The active ingredients will do likewise.

Both of the active ingredients are synthetic variations on pyrethrin. They normally biodegrade in a matter of days to weeks in an outdoor environment. So after doing the above, just let the grill set for a while before using it.
posted by jedicus at 6:28 AM on July 10, 2013 [4 favorites]

Yeah, I agree that a thorough scrubdown and burn-off will do the trick. I would be concerned about chemicals burning off inside the house if I heated the racks in the oven, so I agree that using the grill at the highest setting is the best bet to burn-off any residual chemicals.
posted by shortyJBot at 6:33 AM on July 10, 2013 [2 favorites]

What's your usual grill cleaning routine? A slightly more strenuous version of that should do just fine.
posted by RainyJay at 6:37 AM on July 10, 2013

I wouldn't put it in your oven.
posted by devnull at 7:27 AM on July 10, 2013

In addition to hosing it off, also consider using a metal brush.
posted by oceanjesse at 7:41 AM on July 10, 2013

Best answer: I am a toxicologist (but not your toxicologist) and I do computational prediction of toxicity. I just ran those compounds through our software and did a quick literature search and nothing came up. Looking at the structure there is nothing that I would worry about and would certainly continue to use the grill. I would obviously wash it and give it a burn in just to be sure, but those compounds aren't the most stable things around and they are likely to be degraded by either microbes on the grill or from the heat alone. (they contain cyclopropyl rings, not known for being the most stable things around)

To make you feel better and hopefully alleviate your chemophobia (probably justly in this case because it is a poison although selectively an insect/fish poison not mammal) pyrethin the parent compound of these is extracted from Chrysanthemum seeds.
posted by koolkat at 7:58 AM on July 10, 2013 [17 favorites]

I have been involved in decontamination studies of pesticide residues. As others have said, these are some of the more easy to remove compounds. Soap and (hot) water scrub will likely remove most of them. You do need to wash---the half lives of these products are 20-40 days.

A second step to take is to replace the grill in the BBQ and cook as hot as you can. This will help char the remaining residues. I would give it an hour or so on your high setting. This is likely overkill, but afterwards you can be confident that the grill is clean again.
posted by Anonymous 5$ Sockpuppet at 8:23 AM on July 10, 2013

Jeez, I'm a lot lazier than all of you. I'd just fire up the grill and let it burn the chems off.
posted by colin_l at 8:24 AM on July 10, 2013

You coat your grill with worse chemicals than those every time you blacken meat.
posted by flabdablet at 10:43 AM on July 10, 2013 [1 favorite]

Response by poster: koolkat,

Thank you. That's very reassuring.
posted by Area Man at 10:48 AM on July 10, 2013

Be careful about leaving your grill on it's highest setting with all burners on for an hour. I did this once with a Brinkmann, maybe not even 1/2 hour and it not only ruined the grates on the grill, but the cover as well. I ended up having to throw away a $300 grill. Check your grill manual first.
posted by dukes909 at 12:21 PM on July 10, 2013

I suspect, as flabdablet implies, that the very act of grilling is itself more dangerous than the brief exposure you will get to the spray. Not to scare you off steak, as this is a somewhat unsettled area of science, but it's just amusing to consider what we consider alarmingly risky compared to things we are doing every day.
posted by dhartung at 10:13 PM on July 10, 2013

Dhartung is right, you would be much worse off grilling the steaks over charcoal than giving them a little spritz of the pesticide, other than I think that the pesticide would taste bad.
posted by koolkat at 7:30 AM on July 11, 2013