I have a strange obsession/addiction. Whenever I smell chalk,baby powder,talcum powder, perfumes,soap bars, detergent powder, it makes me want to taste it and sometimes the temptation to eat it. Although I have never eaten it.  When I was a kid I used to play with chalk (the one used on a chalkboard) and sometimes I used to feel tempted to eat that chalk, kinda chew it. Is this psychological or is this a  health/medical condition ? (Since I know these products are not meant for consumption, I would never eat them. Yet I get the temptation. Like some sensation in my throat to want to eat or chew it.)