Q. Does one have to check for shaatnez clothing given to a baby or a minor, when there is a possibility that it may have wool and linen? Can one be lenient since the baby or child does not have the mind and intent of wearing it?
A. Minchas Chinuch (551: 5) debates whether one is liable on dressing a minor with shatnez, since he is a shogeg or unintentional wearer, and it may be similar to one checking out a suit in a store. Or since it can be comparable to giving him to eat non-kosher food or keeping Shabbos, it is prohibited.
Oneg Yom Tov (96) and Shoel Umeshiv (1: 1; 206) maintain that one would transgress on a Biblical prohibition.
Minchas Yitzchok (2: 107) asserts that it is prohibited even if the shatnez involved is only Rabbinical.
Horav Shlomo Miller’s Shlit’a opinion is similar.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a