In the chemical industry, sulfuric acid, hydrochloric acid and nitric acid is called three. Small oxygen utilization rate of alkali determination, need to use sulfuric acid or hydrochloric acid. In cooler tube descaling, usually using dilute hydrochloric acid. Acid has a strong corrosive, touching the skin will cause severe burns and difficult to cure, but also cause corrosive poisoning. Therefore, in the use should pay attention to the following points:
　　1) the use of strong acid acid should wear protective clothing, wearing rubber gloves.
　　2) amount of acid to the cylinder, a pipette and never.
　　3) dilute acid, be sure to put the concentrated acid slowly along the wall of the water into the water, and side by side, stirring, so that the heat generated by the rapid spread of the water can not be poured into the open container of concentrated acid. Otherwise, it will cause the water to boil, concentrated acid splash, causing burns accident. Once the acid is spilled on the skin or clothes, rinse immediately with plenty of water. Then with dilute sodium carbonate (sodium carbonate) solution washing.
　　4) the chemical properties of acid is very active, so the acid bottle should be sealed, and to be protected, to prevent rupture. The bottle containing acid is not allowed to heat or sunlight, but is not allowed to contact the fuel.
　　5) occurred strong corrosive poisoning symptoms are lip, mouth and throat burns, heartburn, vomiting or suffocation will happen. The application of magnesia lime, sodium bicarbonate, water or soapy water as an antidote.