Translation guide
A fine powder used to prevent diaper rash and keep a baby's skin dry. In Japanese, the most common term is ベビーパウダー, a loanword from English. There is also a traditional product called 天花粉, but it is less common today.
ベビーパウダー
baby powder
The cosmetic powder applied to a baby's skin to absorb moisture and reduce friction.
The standard modern term, a direct loan from English. Widely understood and used on product labels.
ベビーパウダーを赤ちゃんのおしりにはたく。
I put baby powder on the baby's bottom.
A traditional Japanese baby powder made from rice starch or similar ingredients. Less common today but still recognized, especially by older generations.
In the past, people often used traditional baby powder.