Yes, smoke bombs can absolutely stain clothing and surfaces if you're pointing the device directly at it within 1 foot. Additionally, there are some other factors at play when it comes to smoke grenades staining: Contact Duration: The longer the smoke is in contact with a surface, the more likely it is to leave a stain. Quick exposure might not leave noticeable marks, but prolonged exposure increases the risk of staining. Surface Type: Non-porous surfaces like metal or sealed stone are less likely to be stained than porous surfaces. However, even on non-porous surfaces, residues might need to be cleaned off to prevent any long-term effects. If you're concerned about staining, it's best to use smoke grenades in open, well-ventilated areas away from surfaces you're worried about staining. We are not held liable for any damage to clothes or surfaces.