Here, from Mike W., is a great alternative to toxic chemical toilets for males (at least for urine) at outdoor events. Totally makes sense. Save that nitrogen!
"It is inefficient and unsustainable to haul human waste back in from remote festivals and other places typically populated with port-a-potties. So why not use on-hand materials to make something simple and green?
Thus L’Uritonnoir by Faltazi which turns an everyday farm item into a urinal by means of simple funnels attached on various sides and connected via a loop running around the perimeter. The composted results can be recycled right back into the local land. …"