According to the the People's Republic of China GB15346-94 chemical reagent packaging standard: Article 9.1.1.M stipulates: if the validity period is required to be indicated, the validity period must be indicated; Production date or production batch number.

classification of chemical reagents in our country:

Excellent grade pure (GR, green label): high content of main components, high purity, suitable for accurate analysis and research work, some can be used as reference materials.

Analytically pure (AR, red label): high content of main components, high purity, low interference impurities, suitable for industrial analysis and chemical experiments.

Chemical purity (CP, blue label): high content of main components, high purity, interference impurities, suitable for chemical experiments and synthetic preparation.

Experimental purity (LR, yellow label): high content of main components, poor purity, no choice of impurity content, only suitable for general chemical experiments and synthetic preparation.

Indicator and stain (ID or SR, purple label): unique sensitivity is required.

Designated level (ZD): chemical reagents customized for specific users according to the quality control indicators required by users.

Electronically pure (MOS): suitable for the production of electronic products, electrical impurities content is very low.

Equivalent reagent (3N, 4N, 5N): the main component content is above 99.9%, 99.99%, 99.999% respectively.

Validity period of chemical reagents: Chemical reagents will be affected by external factors such as temperature, light irradiation, air and moisture during storage, transportation and sales, and are prone to deliquescence, mycin, discoloration, polymerization, oxidation, volatilization, sublimation and Physical and chemical changes such as decomposition make them ineffective and unusable. Therefore, it is necessary to adopt reasonable packaging, appropriate storage conditions and transportation methods to ensure that chemical reagents do not deteriorate during storage, transportation and sales. For some storage and transportation have special requirements should be handled according to special requirements. Some chemical reagents have a certain shelf life, so we must pay attention to them when using them.

The validity of chemical reagents varies greatly with the change of chemical properties. In general, chemically stable substances, the longer the shelf life, the simpler the preservation conditions. Preliminary judgment of the stability of a substance, can follow the following principles:

Inorganic compounds, as long as it is properly kept and the packaging is intact, can be used for a long time. However, those substances that are easy to oxidize and deliquescence can only be stored for a short period of time (1-5 years) under the conditions of avoiding light, shade and dryness, depending on whether the packaging and storage conditions meet the requirements.

Organic small molecular weight compounds are generally more volatile, packaging tightness is better, can be stored for a long time. But easy oxidation, thermal decomposition, easy polymerization, photosensitive substances, in the dark, shade, dry conditions, only a short period of time (1-5 years) to save, depending on the packaging and storage conditions are in line with the provisions.

Organic polymers, especially oils, polysaccharides, proteins, enzymes, peptides and other life materials, are extremely vulnerable to the influence of microorganisms, temperature and light, and lose their activity or deteriorate. Therefore, they should be refrigerated (frozen) and stored for a short time.

In principle, reference substances, standard substances and high-purity substances shall be kept in strict accordance with the preservation regulations to ensure that the packaging is intact and avoid being affected by the chemical environment, and the preservation time shall not be too long. In general, the reference substance must be used within the validity period.