Salicylic acid is a soluble organic acid

Salicylic acid is a fat-soluble organic acid, chemical formula C7H6O3.  Appearance is white crystalline powder, melting point is 158~161℃.  It exists in willow bark, white pearl leaves and sweet birch in nature, and is an important fine chemical raw material, which can be used in the preparation of aspirin and other drugs.  

Chemical properties of salicylic acid  

Stable at room temperature.  Decomposition to phenol and carbon dioxide by rapid heating.  It has partial acidness.  This product irritates skin, mucous membrane, because can react with the protein in the body tissue, has the corrosive effect.  It can make the cornea proliferate after dissection.  It is less toxic than phenol, but large doses can cause vomiting, diarrhea, headache, sweating, rashes, shortness of breath, acidosis and excitement. 

Its aqueous solution is acidic.  Have antipyretic analgesic effect.  Used as food preservative, dye disinfectant, medicine, etc.  The oral LD50 of mice ranged from 0.48 g/kg to 1.65g/kg, and the intravenous minimum lethal dose was 60mg/kg.  The oral LD50 of rats was 1.5-2.0 g/kg.  Moderate irritation, low toxicity through skin and mouth.  The lethal dose for adults is estimated to be about 5 ~ 15g, and some people think it is 20 ~ 30g.  Mild poisoning occurs when the blood concentration is 55-85mg %, moderate poisoning occurs when the blood concentration is 80-110mg %, severe poisoning occurs when the blood concentration is 125-145mg %, and death occurs when the blood concentration is 160-180mg %.  

Salicylic acid toxicology  

Salicylic acid and salicylic acid salt poisoning, mostly for a large amount of swallowing, or in the treatment of excessive dosage and frequent use caused by.  Salicylic acid and salts can also be absorbed through the skin to cause toxicity, especially methyl salicylate.  Its toxicological effects are as follows:  

1.  Central nervous system: the action of this kind of medicaments to central nervous system, begin to be excited (breath is enhanced, terror, be agitated, tremor, convulsion etc.) by excited turn to restrain gradually, can produce oedema even.  

2.  Electrolyte and acid balance by breathing, hyperventilation, can cause respiratory alkalosis, due to the base after discharge and metabolism by change caused by salicylates (because of salicylate on inhibition of transaminase and dehydrogenase, the metabolism of acetyl-coa through the Krebs cycle hindered to increase the ketone body).  Can cause metabolic acidosis.  

3.  Digestive system: the digestive tract has a direct stimulating effect.  Especially salicylic acid.