There aren't any bath bombs that are totally safe, particularly for people with sensitive skin. Sadly, the size of the bath bomb doesn't really matter — smaller bombs can have concentrated amounts of potential allergens.When used as directed, bath bombs and bath fizzies are safe. Skin irritation can occur in some people and eye irritation is expected to occur if splashed in the eyes. Unintentional ingestion of small amounts is expected to cause minor effects such as oral irritation, nausea, vomiting, and diarrhea.