Andycuk7,
There are regulations for crop protection chemicals (pesticides, herbicides, fungicides) used in crops that list what can be applied in what crops and what are the residue tolerances or limits. One source for these regulations is WHO, but normally each country has its own regulations. In USA the EPA ensures that chemicals are registered for use in specific crops and sets up the tolerances. But I don’t think this is what you are looking for, since this applies only for chemicals registered to be used in crops. Since the weed killer that you are using is not intended for use in the product, it shall be treated as any chemical, and all food safety regulations or guidelines will focus on preventing cross-contamination.
My preferred option on this would be to hire a professional company to do it for you, as per GFS requirements you will need to be sure that they are licensed and trained as pesticide applications, must be insured and you need to have a service agreement (contract or list of what they are going to do and when). Also, they should go thru your vendor approval process, which may be as simple as being sure the vendor has these requirements.
Now, if you want to “do it yourself” it may be a little more complicated. The person doing the applications must be trained (Chemical safety, mixing, application, calibration…) and probably be licensed or worked under a licensed supervisor, you need to control the chemical inventory, provide proper storage, maintain MSDS sheets and basically do anything to prevent cross-contamination.
I personally prefer to leave this to professionals, so I don’t have to deal with more chemicals in the plant. A good practice is to get the chemical applied when there is less risk of cross contamination (such as nights, early mornings or even weekends) to prevent contamination by traffic or drift.
Now, there is better option, and it is not use week killer, or at least minimize the use of week killer thru the use of best tuff management practices to maintain a healthy turf. You of course would have to hire a expert gardener or lawn maintenance company since this is a total different science that requieres special knowledge an expertise.
Edited by Antores, 10 May 2011 - 03:01 PM.
