Any branch of chemistry involves the use of certain chemicals. Given the fact that reagents are substances that can cause serious harm to human health, certain requirements are imposed on their storage.
7 group
Chemical reagents of this group have increased toxicity, so there are certain requirements for their placement. They are located in a special safe located in the laboratory. The assistant has the key to it, as well as the chemistry teacher.
In educational schools, the storage of chemical reagents is prohibited, and in the laboratories of higher educational institutions their presence is allowed only with a special order from the head of the educational institution. The laboratory assistant keeps a strict record of the consumption of such substances, making entries in a special journal.
List of inorganic reagents permitted in the school laboratory
We list the main inorganic chemical reagents that are allowed for demonstration experiments in chemistry classes at school:
- simple substances: metallic sodium, crystalline iodine, liquid bromine;
- caustic soda, oxides of metals and nonmetals;
- salts, including complex compounds, dichromates and chromates;
- acid solutions.
Organic matter
We note organic reagents and substances that a chemistry teacher can use when forming practical skills for schoolchildren:
- aniline;
- organic acids;
- benzene;
- phenol;
- formalin.
Reagent Safe Requirements
A safe, installed in laboratory chemistry, designed to store reagents of group 7, is most often made from solid sheets of metal. Installation of a wooden structure is also allowed if the safe outside is covered with iron, the thickness of which will be at least 1 mm.
There are requirements for the location of the safe. Given that reagents are sources of increased danger, you need to choose a place for a safe so that it can be easily taken out in case of fire.
A typical list of substances with high physiological activity
Among the reagents that have similar properties, we can mention metallic zinc, calcium, lithium, calcium oxide and hydroxide , metal nitrates , potassium iodide , potassium permanganate, zinc compounds. Such reagents are hazardous substances, therefore experiments with them are allowed only under the direct supervision of a teacher.
Also included in the list are organic substances such as diethyl ether, acetone, alcohols, cyclohexane, chloroform, and crude oil. Such reagents are substances that affect the human nervous system, therefore they are excluded from the list of chemical preparations used in ordinary educational schools for practical work and laboratory experiments.
In the classroom, only 8 groups of reagents are allowed to be placed (locked), which are used during practical work and laboratory experiments. Such reagents are substances that are safe for the health of children. For example, a solution of sodium chloride , potassium sulfate , calcium chloride.
Storage rules for small schools
In small rural schools that do not require a special area for the laboratory room, special attention should be paid to the storage of chemical reagents. For example, an acid reagent in which the concentration of the active substance exceeds 50 percent should be located in a closed and tied plastic bag.
Alkalis that are in a solid state of aggregation should be at a considerable distance from acids, with the preservation of factory packaging. An opened bottle with caustic soda or potassium should be tightly closed, then placed in a plastic bag or jar, which is tightly closed with a cork.
Only an aqueous solution of ammonia and hydrochloric acid has a high vapor pressure, so it is so important to check the tightness of their packaging. As additional safety measures when working with similar reagents, the use of additional sealing plugs, plastic bags per can is considered.
In the absence of space for a separate placement of reagents of 2.5.6 groups, their joint arrangement in one cabinet is allowed. At the same time, a separate shelf must be assigned to each group. The best option would be to place reagents of group 5 on the upper shelf, below you can put jars of substances of group 6, put reagents of group 2 in the bottom of the cabinet.
Conclusion
In any educational institution in which it is intended to use chemical reagents for lessons and extracurricular activities, there is a special instruction according to which a certain space is allocated for them. Classical laboratory sectional cabinets used to place chemical reagents are lined with modern polymeric materials that are resistant to the negative effects of aggressive environments.
In the absence of such a protective lining, it is important to coat all the internal parts of the cabinet with oil paint in 2-3 layers, make sides on the shelves, the height of which should be 3 cm.
In order to protect the shelves from water, several layers of plastic film are laid on them. Furniture placement in laboratory chemistry is carried out with strict observance of fire safety rules.
On the laboratory wall or on the door of the chemistry cabinet, there must be instructions on labor protection approved and signed by the director of the educational institution, bearing the seal of the organization.