Concentration of the chemical. Duration of exposure. Alkalis cause the most severe injury due to rapid tissue penetration. Immediate drenching of affected part with copious amounts of water can aid in limiting tissue damage. The eye can look normal even when damage is sufficient to cause blindness.
Immediate eye wash drenching of the eye is imperative.
Injuries look worse immediately but acids penetrate tissue less than alkalis. Begin drenching area immediately with a hose or shower. If the chemical is not water soluble, drench for 1 minute with mineral oil and then for 60 minutes with water or saline. If the chemical is a dry solid or powder, brush it away before drenching, if this is possible and can be done expeditiously. Students should know how to use a safety shower and the eye washer and know where the nearest stations are located.