My understanding is that breathing in dust from the powder is the most pressing concern. I prefer Ilfordís almost-identical ID-11 but avoid dust inhalation simply by lowering each sachet into my container of tempered water and wetting the contents before extracting them. A little gentle swilling is needed to get the contents out for mixing but itís not problematic. By wetting the powder first the dust issue is completely avoided.
Itís all very well to say, mix chemicals outside on a balcony. But what if itís windy? You might have more dust exposure as a result, than may be the case carefully mixing developer indoors in your laundry or bathroom. Surely it depends on the prevailing weather as to whether mixing outdoors is best.