Hair mousse typically contains a combination of ingredients that help create volume, hold, and texture in the hair. Some common ingredients found in hair mousse include water, alcohol, polymers, silicone, and various conditioning agents. These ingredients work together to provide the desired styling effects. Regarding safety, hair mousse, when used as directed, is generally considered safe for use. However, it is important to note that some individuals may have sensitivities or allergies to specific ingredients. It is always a good idea to check the product label for any potential allergens and perform a patch test on a small area of the skin before using it on your hair. If you have any concerns or specific allergies, it is advisable to consult with a dermatologist or healthcare professional who can recommend suitable products based on your needs.