During Playtime, My Son-in-law Rough Houses With His 6 Month

During playtime, my son-in-law rough houses with his 6 month old baby. He loves his child. My daughter has asked him not to do this but he won't listen. He frequently tosses him up in the air 24" above his hand grasp, and carries him around the room by his legs, till the baby's face turn red. Is this safe? My husband never did this this our children were older.