Acid and Corrosive Poisoning
Acid and corrosive poisoning cause severe burn injury to the mucus membrane and skin. In severe burn circulatory collapse may occur.
Common corrosive chemicals
Acids
Strong acids — the most common are sulfuric acid, nitric acid and hydrochloric acid (H2SO4, HNO3 and HCl, respectively).Some concentrated weak acids, for example formic acid and acetic acid
Strong Lewis acids such as anhydrous aluminum chloride and boron trifluoride
Lewis acids with specific reactivity, e.g. solutions of zinc chloride
Extremely strong acids (superacids)
Bases
Caustics or alkalis, such as sodium hydroxide (NaOH) and potassium hydroxide (KOH)
Alkali metals in the metallic form (e.g. elemental sodium), and hydrides of alkali and alkaline earth metals, such as sodium hydride, function as strong bases and hydrate to give caustics
Extremely strong bases (superbases) such as alkoxides, metal amides (e.g. sodium amide) and organometallic bases such as butyllithium
Some concentrated weak bases, such as ammonia when anhydrous or in a concentrated solution.
Dehydrating agents
Such as concentrated sulfuric acid, phosphorus pentoxide, calcium oxide, anhydrous zinc chloride, also elemental alkali metalsStrong oxidizers such as concentrated hydrogen peroxide
Electrophilic halogens: elemental fluorine, chlorine, bromine and iodine, and electrophilic salts such as sodium hypochlorite or N-chloro compounds such as chloramine-T.Halide ions are not corrosive, except for fluoride
Organic halides and organic acid halides such as acetyl chloride and benzyl chloroformate
Acid anhydrides
Alkylating agents such as dimethyl sulfate
Some organic materials such as phenol (“carbolic acid”)
Symptoms of Acid and Corrosive Poisoning
Symptoms of ingestion include throat pain, restrosternal discomfort, marked thirst, haematemesis, difficulty in swallowing, breathing and speaking, disorientation and disqumation around mouth. MLD is 1 ml of concentrated acid. Inhalation of volatile acids causes severe irritation of throat and respiratory passage with paroxysmal cough and symptoms of pulmonary edema.
Treatment for Acid and Corrosive Poisoning
a) When ingested : dilute the acid by giving immediately a glass of milk or water to drink. Remember not to give bi-carbonates else heat generated, may do additional damage. Relieve pain and treat shock. Esophagogastroscopy should be done immediately to asses the extent of damage. The endoscope should not be passed beyond the injury. Perforation and peritionitis or bleeding from major vessel require surgery.
b) Eye Contact : Hold the eyelids open and flood the eye with water or normal saline for 15 minutes. Check pH of draining fluid and that of cornea. Continue irrigation with normal saline till corneal pH is 7. Arrange for internal examination of eye.
c) Inhalation : Remove the patient from further exposure to fumes, take out the clothing and treat pulmonary edema.
d) Skin contact : Irrigate the area with water. Relieve pain and treat shock. For hydrofluoric acid burns, inject 0.5ml of 10 percent calcium gluconate with 1 percent xyocaine per square centimeter of burn under the burn area.