I agree with evry post here except Samallaxe's, which was way far off topic anyway.
Greendoctor, Milorganite fixed that problem here. They changed the label ha ha.
Some schools here have been bullied into using "organics." Turned out only about 1/4 of N was from organic source - and that was composted chicken manure. How would you like to get tackled face down in that? Many cases of chronic lung disease are attributable to poultry manure.
I get this question several times a year and I don't even work with homeowners. Usually it is to settle a disagreement between spouses. In Michigan we cannot use the word "safe" in any context with regard to pesticide applications but I have no hesitation in sending a team out to practice or play on a field that was fertilized yesterday or even the same day if they are not routinely tackling each other. In my view, the risk to the grass by letting them back on is greater than the risk to the kids.