The ingredients used to make slime are commonly used household ingredients. Slime recipes using borax are considered less safe because borax is a cleaning agent and can cause irritation when handled/used outside of its determined use. Adult supervision should always occur when making any slime recipe. Aleene’s Original Tacky Glue and Clear Gel Tacky Glues – used in the slime recipes on this site – are nontoxic and safe to handle. Under no circumstances should slime be ingested and hands should always be washed before and after handling slime.