Final answer:
The primary ingredient in styptic powder or liquid is aluminum sulfate, which acts as an astringent to contract tissues and stop bleeding. It may also contain antiseptics like denatured alcohol or witch hazel and sometimes menthol for numbing.
Step-by-step explanation:
The primary ingredient in styptic powder or liquid, which is used to stop bleeding from minor cuts or wounds, is aluminum sulfate. This substance works as an astringent, causing tissues to contract and thus helping to stop the bleeding. Along with aluminum sulfate, styptic products may contain other substances like antiseptics (such as denatured alcohol or witch hazel) to prevent infection, and in some cases, menthol to numb irritated skin. Other compounds like aluminum chloride hexahydrate, calcium sulfate variants, or even hydrogen peroxide (H₂O₂), which has healing properties, may also be included in formulations for wound care, though hydrogen peroxide is advised against for repeated application due to potential risks like gas embolism formation. However, aluminum sulfate is the key astringent component for the styptic effect.