Why does baby powder expire?

Can I still use it? It's cornstarch baby powder a couple years old. I don't get why it would expire.Why does baby powder expire?
The mixture of chemicals may irritate baby's skin after being exposed to air for so long. After years, I'm sure some moisture has gotten in there one way or another. There may be some tiny parasites in there. Toss it, and buy some more.Why does baby powder expire?
iv never heard of baby powder expiring but i would still use it
Baby powder doesn't expire!!!!
everything expires after sometime. throw it away. it isnt that expensive to buy new ones isnt it?
weird? I'd say it should be fine cuz you are not gonna eat it.