Dec 27, 2011 – Keep It or Toss It?
QUESTION:
Thank you for being such a great wealth of knowledge pertaining to pest questions. Here's another. I was working with Suspend SC and Bifenthrin liquid spray yesterday, mixed with water in a 1 gallon sprayer, and some of the Bifenthrin might have touched part(s) of my leather deck shoe style shoes. The Bifenthrin label advises to discard leather items like shoes, belts, and watches that get Bifenthrin on them, but does this mean the concentrated form, or the mixed spray form? I have read that the average expected time that Bifenthrin is potent enough to provide pest control is about 3 months. After that time period, or maybe even a year, isn't the amount applied to the leather negligible? Does the label set up this guideline to discourage personal decisions (a little bit of mist on the outside of a watchband vs. a shoe being soaked with liquid spray)?
ANSWER:
I'll try to keep myself out of trouble here by dancing around my answer a bit, since obviously I am going to have to offer an opinion. First is that wording advising you to remove and destroy all contaminated leather articles. This wording seems only to be on the MSDS for the MasterLine Bifenthrin, and in some discussions in the past with regulatory people in my local area it is felt that the MSDS, in general, refers to contamination from the concentrate product, although this may not always be the opinion of regulators, so please do discuss this with your local regulatory inspectors. The MSDS in general may also refer to handling or exposure during a spill or some other problem with a pesticide, while the Label is the document that gives you the information on handling during normal use. The Label, in this case, does not advise the disposal of contaminated leather articles, and in fact did not seem to address "leather" shoes or other articles at all.
View past Ask Mr. Pest Control questions.
Thank you for being such a great wealth of knowledge pertaining to pest questions. Here's another. I was working with Suspend SC and Bifenthrin liquid spray yesterday, mixed with water in a 1 gallon sprayer, and some of the Bifenthrin might have touched part(s) of my leather deck shoe style shoes. The Bifenthrin label advises to discard leather items like shoes, belts, and watches that get Bifenthrin on them, but does this mean the concentrated form, or the mixed spray form? I have read that the average expected time that Bifenthrin is potent enough to provide pest control is about 3 months. After that time period, or maybe even a year, isn't the amount applied to the leather negligible? Does the label set up this guideline to discourage personal decisions (a little bit of mist on the outside of a watchband vs. a shoe being soaked with liquid spray)?
ANSWER:
I'll try to keep myself out of trouble here by dancing around my answer a bit, since obviously I am going to have to offer an opinion. First is that wording advising you to remove and destroy all contaminated leather articles. This wording seems only to be on the MSDS for the MasterLine Bifenthrin, and in some discussions in the past with regulatory people in my local area it is felt that the MSDS, in general, refers to contamination from the concentrate product, although this may not always be the opinion of regulators, so please do discuss this with your local regulatory inspectors. The MSDS in general may also refer to handling or exposure during a spill or some other problem with a pesticide, while the Label is the document that gives you the information on handling during normal use. The Label, in this case, does not advise the disposal of contaminated leather articles, and in fact did not seem to address "leather" shoes or other articles at all.
Now, it is normal for pesticide handling information or guidelines to advise against the wearing of leather shoes, and for exactly the reason you have mentioned. Leather will absorb liquids and these then are extremely hard to get back out of the leather. Since you are not going to throw leather shoes in the washing machine it means that any appreciable amount of pesticide that has soaked into that leather will be there awhile, and potentially this places it in contact with your skin every time you wear that article of clothing. The same goes for leather gloves, and I suppose leather pants if you are so inclined. Where you expect to have normal pesticide exposure to your work clothing it should be clothing that can be laundered at the end of that work day. Some clothing may have mandates regarding the laundering, such as gloves (washing), respirator (cleaning), pants and shirts (coveralls), while other PPE may not be included in these mandates (safety glasses, hat, shoes) leaving it up to the discretion of the applicator to use good common sense and wash these things as needed.
So, if you do wear leather shoes during your pesticide applications and are doing an operation where shoe contact is expected, such as spraying a lawn, then you should wear rubber boots over the leather shoes. Since most of your applications are not this kind then the only exposure to your shoes should be that trace amount of mist that may land on the shoes during a day's work, and I believe that this diluted material in that insignificant amount is not a reason to rip off the boots and throw them away. "Some" level of exposure to the active ingredient during a spray operation of diluted material is unavoidable, since your face is still exposed as is some hair. But, you cover up as much as is practical and reasonable for the toxicity level of the materials you are using, and then launder these clothing items as needed if they are "contaminated". In California, where I am most familiar with regulations, "daily laundering" of work clothing may not even be required when using Category 3 products, such as the MasterLine Bifenthrin with its "CAUTION" signal word.
I suggest that throwing away contaminated leather articles is most appropriate if they were contaminated with concentrate, and slight contact by the diluted spray or mist would not justify disposal of these. However, you should consider applying some sort of water-proofing material to the outside of the shoes so that you eliminate the potential for materials soaking in. Just how long that active ingredient will last within the leather is probably anyone's guess, but 3 months may be a bit on the long side of this residual. In your case you also hint that your spray "might have" touched your shoes, and to me this sounds like you didn't exactly get them soaked, and thus the problem seems not to be such a problem. Keep the shoes, apply water proofing, and avoid contact as much as possible.
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