Packaging requirements for sodium hydroxide (caustic soda)

Packaging requirements for sodium hydroxide (caustic soda)

NaOH solid dissolved in water exotherm; also known as caustic soda, caustic soda, caustic soda, is a common, important base, the English name sodiun hydroxide (alias Caustic soda).

Chemical NaOH
The formula amount is 40.01. The density is 2.130 g/cm 3 , the melting point is 318.4 ° C, and the boiling point is 1390 ° C. Pure anhydrous sodium hydroxide is a white translucent, crystalline solid. Sodium hydroxide is very soluble in water, and its solubility increases with increasing temperature, and it can release a lot of heat when dissolved. Its aqueous solution has astringent and slippery feel, the solution is strongly alkaline, and it has all the properties of alkali. Commercially available caustic soda has two kinds of solid and liquid: pure solid caustic soda is white, and has a block, a sheet, a rod, a granular shape, and is brittle; a pure liquid caustic soda is a colorless transparent liquid. Sodium hydroxide is also soluble in ethanol and glycerin; but it is insoluble in ether, acetone and liquid ammonia. It has corrosive effect on fiber, skin, glass, ceramics, etc., and will release heat when dissolved or concentrated solution is diluted; neutralization reaction with inorganic acid can also generate a large amount of heat to form corresponding salts; and metal aluminum and zinc, non-metal The reaction of boron and silicon releases hydrogen; it disproportionates with halogens such as chlorine, bromine and iodine. The metal ion can be precipitated from the aqueous solution into a hydroxide; the saponification reaction of the oil and fat can be carried out to form the corresponding sodium salt of the organic acid and the alcohol, which is the principle of removing oil stain on the fabric.

Sodium hydroxide is widely used. In chemical experiments, in addition to being used as a reagent, it can also be used as an alkaline desiccant because of its strong hygroscopicity. Caustic soda is widely used in the national economy, and many industrial sectors require caustic soda. The sector that uses the most caustic soda is the manufacture of chemicals, followed by papermaking, aluminum smelting, tungsten smelting, rayon, rayon and soap manufacturing. In addition, in the production of dyes, plastics, pharmaceuticals and organic intermediates, the regeneration of old rubber, the production of sodium metal, water electrolysis and inorganic salt production, the preparation of borax, chromium salts, manganates, phosphates, etc., also use A large amount of caustic soda. Industrial sodium hydroxide should comply with national standard GB 209-93; industrial ion exchange membrane method sodium hydroxide should meet the national standard GB/T 11199-89; chemical fiber sodium hydroxide should meet the national standard GB 11212-89; edible hydrogen Sodium oxide should comply with national standard GB 5175-85.

In the industry, sodium hydroxide is often called caustic soda, or caustic soda, caustic soda. This is because the thicker sodium hydroxide solution splashes on the skin, which can corrode the epidermis and cause burns. It has a solubilizing effect on proteins, which is highly irritating and corrosive. Dropping into the rabbit eye with a 0.02% solution can cause corneal epithelial damage. Intraperitoneal LD50 of mice: 40 mg/kg, rabbit oral LDLo: 500 mg/kg. Dust irritates the eyes and respiratory tract, corrodes the nasal septum; splashes on the skin, especially on the mucous membranes, can produce soft palate, and can penetrate into deep tissues, leaving scars after burns; splashing into the eyes, not only damage the cornea, but also deep eyes Tissue damage, severe cases can cause blindness; misuse can cause digestive tract burns, colic, mucous membrane erosion, vomiting bloody stomach contents, bloody diarrhea, sometimes hoarseness, difficulty swallowing, shock, perforation of the digestive tract, stomach can occur later Intestinal stenosis. Due to its strong alkalinity, it can cause pollution to water bodies, and plants and aquatic organisms should be noted.

Regulations on the Safety Management of Chemical Dangerous Goods (promulgated by the State Council on February 17, 1987), Regulations on the Administration of Safety Regulations for Chemical Dangerous Goods (Hua Fafa [1992] No. 677), and Regulations on the Safe Use of Chemicals in the Workplace ([ 1996] Labor Department issued No. 423) and other regulations, for the safe use, production, storage, transportation, loading and unloading of chemical dangerous goods, etc.; "Classification and marking of commonly used dangerous chemicals (GB 13690-92) The material is classified as Class 8.2 alkaline corrosion products; "Safety Technical Regulations for Diaphragm Caustic Soda Production (HGA001-83)" and "Safety Technical Regulations for Mercury Production by Mercury (HGA002-83)" have been specifically regulated.

Protective equipment should be worn when contact with caustic soda in large quantities, and work clothes or work caps should be made of cotton or a suitable synthetic material. Operators must wear work clothes, masks, safety glasses, rubber gloves, rubber aprons, long rubber boots and other labor protection products. Neutral and hydrophobic ointments should be applied to the skin. When contacting flake or granular caustic soda, there should be ventilation in the workplace. The maximum allowable concentration in indoor air is China MAC 0.5 mg/m3 (calculated as NaOH), and American ACGIH TLVC 2 mg/m3. A hood-type powered air-filtered dust-proof respirator must be worn when it is exposed to dust. Wear an air respirator if necessary. Operators must be specially trained to strictly follow the operating procedures. Operators are advised to wear a hood-type electric air-filtered dust-proof respirator, rubber-resistant acid-base suit, and rubber-resistant acid-base gloves. Keep away from flammable and combustible materials. Avoid dust. Avoid contact with acids. Lightly load and unload during handling to prevent damage to packaging and containers. Equipped with leakage emergency treatment equipment. Empty containers may be harmful residues. When diluting or preparing a solution, add alkali to the water to avoid boiling and splashing. Wear protective glasses and gloves when handling spills, sweep up, slowly pour into a large amount of water, rinse the floor with water, and put the diluted sewage into the wastewater system. If the lye touches the skin, it can be washed with 5~10% magnesium sulfate solution; if it is splashed into the eyes, it should be washed with a large amount of boric acid aqueous solution immediately; when a small amount of food is eaten, use vinegar, 3~5% acetic acid or 5% dilute hydrochloric acid, and a large amount. Neutralize with orange juice or lemon juice, drink egg white, milk or vegetable oil and seek medical attention quickly. It is forbidden to induce vomiting and gastric lavage.

Solid sodium hydroxide can be tightly packed in a 0.5 mm thick steel drum with a net weight of no more than 100 kg per barrel; a full or open glass drum outside a plastic bag or a two-layer kraft paper bag; a threaded glass bottle and an iron cap Ordinary wooden boxes outside glass bottles, plastic bottles or metal drums (cans); threaded glass bottles, plastic bottles or tinned steel drums (cans) full of bottom plate boxes, fiberboard boxes or plywood boxes; tinned steel drums Corrugated boxes (cans), metal drums (cans), plastic bottles or metal hoses. Packaging containers should be complete and sealed and should have a distinctive "corrosive" mark. When transported by rail, steel drums can be transported by open-air vehicles. The packaging should be complete at the time of shipment and the loading should be secure. During transportation, ensure that the container does not leak, does not collapse, does not fall, does not damage, moisture and rain. If the packaging container is found to be rusted, cracked, holed, melted, etc., it should be replaced immediately or shipped early. The container can be repaired by soldering. It is strictly forbidden to mix and transport with flammable materials or combustibles, acids, food chemicals, etc. Transport vehicles should be equipped with leakage emergency handling equipment when transporting. Do not store and mix with combustibles and acids. In case of fire, water, sand and various fire extinguishers can be used for fire fighting, but firefighters should pay attention to the corrosiveness of the water after it is dissolved in caustic soda.

When storing the solid sodium hydroxide in the chemical laboratory, care should be taken to seal the reagent bottle to prevent it from being exposed to the air and absorbing moisture or reacting with carbon dioxide. Caustic soda can be obtained by electrolyzing a salt solution or by reacting sodium carbonate with lime milk.