Nov 2, 2011 – Fog In or Out
QUESTION:
We are having a discussion regarding aerosol "foggers" like CB-80. When we treat for roaches we fog the cabinets and other voids to flush the roaches. Some people say that all of the windows in the house have to be closed to contain the "fog". I don't believe it makes any difference whether windows are open or closed. What is your opinion?
ANSWER:
Well, I am pleased that you asked for my opinion, because that is pretty much what I will offer. I have never heard of any studies or sat through any classes where someone definitively stated the answer to this question. We have to recognize that the mist that comes out aerosols like a CB-80 consists of droplets, and droplets will tend to go as far as air turbulence takes them. Since pyrethrum has such a very short residual what you are most relying on with this use of the aerosol is to contact the roaches directly with the spray. Certainly there is going to be some level of pyrethrum vapors left in the air once the diluents from the aerosol evaporate, but this has never seemed to be part of the flushing effect of pyrethrum. Flies hovering in air where pyrethrum vapors are present will be repelled from the area, and if captive in that air space long enough could be killed. Roaches, not so much.
I think that the only reason you would need to close all the windows would be if there is such a wind flow through the house that it might be carrying the mist out quickly. However, even then your treatment within cabinets and other voids should be contained well enough to do whatever it is going to do. A better approach might be to use a crack and crevice tube on a pyrethrum aerosol that allows you to treat directly INTO the crevices around the kitchen area. This not only offers a much better chance of the pyrethrum hitting the hidden roaches, but also prevents the pyrethrum (it is, after all, a pesticide) from landing all over the exposed surfaces inside the cabinets.
Now, after saying all of that I will refer to the most important opinion, and that is the Product label, and on the Label for CB-80 it very specifically says "close doors and windows before spraying". Since this wording is on the Label it becomes mandatory, and you have no choice but to follow these instructions. It goes on to say that following the application you should keep the area closed for at least 15 minutes and then open it up again and ventilate before allowing occupants back in. For cockroaches it suggests that "for best results spray directly on cockroaches", essentially the advice I offered above.
In this case then it appears that closing those windows is a requirement in order to follow the directions on the product Label.
View past Ask Mr. Pest Control questions.
We are having a discussion regarding aerosol "foggers" like CB-80. When we treat for roaches we fog the cabinets and other voids to flush the roaches. Some people say that all of the windows in the house have to be closed to contain the "fog". I don't believe it makes any difference whether windows are open or closed. What is your opinion?
ANSWER:
Well, I am pleased that you asked for my opinion, because that is pretty much what I will offer. I have never heard of any studies or sat through any classes where someone definitively stated the answer to this question. We have to recognize that the mist that comes out aerosols like a CB-80 consists of droplets, and droplets will tend to go as far as air turbulence takes them. Since pyrethrum has such a very short residual what you are most relying on with this use of the aerosol is to contact the roaches directly with the spray. Certainly there is going to be some level of pyrethrum vapors left in the air once the diluents from the aerosol evaporate, but this has never seemed to be part of the flushing effect of pyrethrum. Flies hovering in air where pyrethrum vapors are present will be repelled from the area, and if captive in that air space long enough could be killed. Roaches, not so much.
I think that the only reason you would need to close all the windows would be if there is such a wind flow through the house that it might be carrying the mist out quickly. However, even then your treatment within cabinets and other voids should be contained well enough to do whatever it is going to do. A better approach might be to use a crack and crevice tube on a pyrethrum aerosol that allows you to treat directly INTO the crevices around the kitchen area. This not only offers a much better chance of the pyrethrum hitting the hidden roaches, but also prevents the pyrethrum (it is, after all, a pesticide) from landing all over the exposed surfaces inside the cabinets.
Now, after saying all of that I will refer to the most important opinion, and that is the Product label, and on the Label for CB-80 it very specifically says "close doors and windows before spraying". Since this wording is on the Label it becomes mandatory, and you have no choice but to follow these instructions. It goes on to say that following the application you should keep the area closed for at least 15 minutes and then open it up again and ventilate before allowing occupants back in. For cockroaches it suggests that "for best results spray directly on cockroaches", essentially the advice I offered above.
In this case then it appears that closing those windows is a requirement in order to follow the directions on the product Label.
View past Ask Mr. Pest Control questions.
