The hidden dangers and countermeasures of sodium azide

Sodium azide, also known as “sodium triazide”, chemical formula NaN3, molecular weight 65.01, white hexagonal crystal, tasteless, odorless, and pure without moisture absorption. Highly toxic. The relative density is 1.846.

Sodium azide, similar to cyanide, has an inhibitory effect on cytochrome oxidase and other enzymes, and can prevent the formation of oxygenated hemoglobin in vivo, and has a significant antihypertensive effect. Irritating to eyes and skin. If inhaled, taken orally or through the skin, it can cause death by poisoning. Oral administration of this product in patients with hypertension has a significant antihypertensive effect. This product may have azidoic acid gas to escape in the organic synthesis, inhalation poisoning has dizziness, weakness, blurred vision, difficulty in breathing, faintness, blood pressure reduction, bradycardia and so on.

NaN3 belongs to drama drug, it is very sensitive to heat explode agent. When it is used in organic synthesis, many people have suffered a lot due to its explosive properties, such as sampling, reaction post-treatment, reaction products and treatment of post-treatment liquid. As a result, it not only causes losses due to reaction failure, delays the completion of projects, but also may cause injuries to people.

Hidden Dangers and Countermeasures:

1. NaN3 is prone to explosion when heated, subjected to friction, vibration and impact. Therefore, the metal spoon or scraper can not be used for sampling and weighing operations, only the horn spoon can sample.

2. Sodium azide is highly toxic, with a LD50 of 27mg/Kg (rat, transoral). Therefore, all utensils exposed to NaN3 and the post-treatment aqueous solution should be dissolved and detoxified with NaClO.

3. In the synthesis process, the excess NaN3 or organic compounds with azide are usually mild in the solution. Even if heated, the reflux is safe, but when the solvent is concentrated and nearly dried, the azide will become very unstable and prone to violent explosions. Therefore, it is not possible to concentrate the reaction liquid directly. If the reaction requires warm reflux, remember that the condensed water must be opened to prevent the solvent from evaporating and drying and causing an explosion.

4. In the post-treatment, if the product is stable under alkaline conditions, the PH of the system is better than 9; in the alkaline atmosphere, the excess sodium azide can be washed with water. If the PH is less than 9 or more acidic, the extra NaN3 becomes a water-resistant, more explosive HN3.

5. Compounds with azide (-N3) are also prone to explosion when heated, shaken or chafed. Azidyl molecules are usually intermediates and are rarely used as end products. Only zidovudine and the antibiotic azidicillin are known to be the preferred treatment for AIDS.

6, with azidyl products have the risk of explosion, such as no matter what method to get azidyl solid products, should be careful, do not contact with metal, do not be heated, do not violent friction, in order to prevent the occurrence of dangerous.

7, post-processing of the aqueous solution, usually contains excessive NaN3, general first, with sufficient quantity of water for at least 100 times the excess sodium azide water to dilute, under stirring, after treated with sodium hypochlorite solution, according to the excess of 1 gram of NaN3 about 10 ml of the proportion of NaClO saturated solution processing, with starch potassium iodide finally test paper for testing.