My instructions for the MK III autostart say 2 1/2% in one part and 3 % oil in another but 2 cycle premix oil either way.
Having worked on MD-80 and MD-11 both use Skydrol and the company had outside shower heads with a big pull chain in case someone got sprayed. On the C-17 the hydro fluid is based on veggie oil and is not a burning experiance (like paint stripper) like Skydrol was. We use sealants that have major health risks and cause Cancer AKA Zepher
Health issues can vary with each person but Zepher kills everyone equally. Use gloves, resperator and safety glasses or shield when mixing fuels and keep it out of the house at all times.