Sometimes fresh compost made from yard-waste can have enough residual pesticide to kill vegetable, but not for long, and it might be hard to distinguish that effect from still "hot" compost contacting green plants. A season or two will leach that stuff out.

Thank you for your reply, I was thinking health impact from ingesting food from it.

The concerns about contaminated or so-called "killer" compost are a bit outdated. About 10 years ago or so, this was a real concern - these herbicides were extremely persistent and remained viable in compost for a number of years and could disrupt the growth of a variety of plant types.

However, when the situation became known, steps were taken to limit the use of these pesticides and more importantly, restrict them for being included in municipal and private compost operations. These herbicides are no longer available to the general public and agencies using them (golf courses, some agriculture, road crews) are prohibited from including treated plant material or grass clippings in commercial compost operations. They must dispose of the material onsite or via their own composting operation.

As to ingesting it, even if present in the compost, it is highly unlikely that you would be consuming anything tainted with the product. Herbicides just don't transfer that way.

There have been a few reports on gw in the past couple of years of people who ended up with killer manure or killer compost from the above mentioned herbicides. It damages some crops more than others. I've linked an informative article below -- which says that the damage is to the plants, and not to humans or animals.
From the article (Ohio State University)
"Most plants are not damaged by clopyralid, even at rates used on lawns and agricultural crops. However, plants in the bean family (Leguminosae), the potato/tomato family (Solonaceae), and the sunflower family (Compositae) are very sensitive to this herbicide. It can stunt tomato, clover, lettuce, pea, lentil, sunflower, pepper, and bean plants at levels in compost as low as 10 parts per BILLION"

You could stick a "canary" tomato plant in there (as in canary in the coal mine). If it grows fine, you know that all is good.

Here is a link that might be useful: Herbicide info sheet

Thank you for the info Elisa! I am really feeling a bit more relieved since you guys answered my post. Thanks so much!

It's important to keep in mind that the reason compost can have herbicides is because they use manure from cows and horses. This means they ATE grass treated with the stuff and it went right through them into the manure. In case you were wondering about its toxicity. :-]

After that, if it's composted by mixing with other ingredients (dilution + biodegradation), then mixed into your soil (more dilution), then you grow plants in the soil, wash off the soil and eat the vegetables (more dilution)...well.

Compost is not good to eat anyway, so don't eat the compost, and especially don't eat manure. :-D