Does all glue contain formaldehyde?

No, not all glue contains formaldehyde. Formaldehyde is a common ingredient in some types of glue, particularly in certain wood glues and adhesives. However, there are many types of glue available that do not contain formaldehyde, such as water-based glues, epoxy glues, and some types of super glue. It is important to check the label or product information to determine if a specific glue contains formaldehyde or not.