Lab reagents expired and still work?

**Information collect from Internet

Food and medicines that have expired may mean that they are not good for our health and should be avoided as much as possible. So with chemicals, does it mean that it is safe to store them within the expiry date and safe to use them beyond the expiry date?

Lab reagents expire when they expire???

Chemical reagents do not have strict expiry dates like food and drugs, and there are no corresponding specific requirements and boundary standards, so it is not reasonable to use the expiry date to judge the effectiveness of chemical reagents. The validity of chemical reagents is related to various factors; it is mainly related to the nature of the reagent itself and the practical application of the user.

How are laboratory reagent expiry dates confirmed?

The validity of laboratory reagents is judged according to the nature of the chemical reagents and storage conditions.

Factors affecting the validity of chemical reagents: the first and most important one is the stability of the chemical. Determine whether the reagent deterioration is mainly based on experience. In general, the longer the preservation validity period of a chemically stable substance, the simpler the preservation conditions.

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 physical and chemical changes such as deliquescence, mycotoxicosis, discolouration, polymerisation, oxidation, volatilisation, sublimation and decomposition, which will render them ineffective and unusable.

Therefore, it is necessary to use reasonable packaging, appropriate storage conditions and transport methods to ensure the quality of chemical reagents. In addition to special provisions, the preliminary judgement of the stability of a substance can follow the following principles.

The validity period of chemical reagents also includes the validity period of the unopened bottle and the validity period of the opened bottle.

Usually, what we say and the expiry date provided by the reagent suppliers refer to the unopened bottle expiry date, which is difficult to generalise due to the storage environment and usage of different users after the bottle has been opened. In general, unless otherwise specified, liquid reagents are valid for one year after opening, and solid reagents are valid for three years after opening.

Users can assess the validity of reagents by reviewing relevant literature, looking at the physicochemical properties of the reagents themselves, and the effect on experimental results. Laboratory reagent validity determination of the stability of most chemicals is still relatively good, the specific circumstances to be determined by the actual use of the requirements.

• - If the analytical data are to be used as a general understanding, or if there are no specific accuracy requirements for the results, the quality level of the chemical reagents can be used as a general requirement.
• - Chemical reagents used for general synthesis preparation, in most cases, the use of industrial-grade chemical reagents can meet the requirements
• - Factory assay data is used to guide the production, the quality indexes of chemical reagents are more demanding, and must be strictly calibrated and judged.
• - Synthesis and preparation of research and certain speciality chemicals, which require very high quality raw materials and require strict control.

Reagents with a long storage period can be used in less demanding test analyses, and reagents that may have deteriorated can be used in comparison with newly purchased reagents to determine whether they have deteriorated. As long as the chemical properties remain unchanged and no impurities are introduced, they can be used in principle.

In short, the effectiveness of chemical reagents, first of all, according to the physical and chemical properties of the chemical reagents themselves to make a basic judgement, and then the preservation of the chemical reagents for the apparent observation, and then combined with the actual situation of the work of the reagents on the results of the impact of the necessary to do a comparison test of old and new reagents to determine whether the reagents appear to be deteriorated, whether they can continue to be used, or whether they can be used to purify the use of the appropriate measures taken.

Experimental equipment to meet the conditions of end-of-life？？

Instruments and equipment after long-term operation and use, constant wear and tear, aging, its productivity, safety and reliability will continue to decline, these instruments and equipment should be scrapped.

1. End-of-life procedures

The end-of-life procedure includes application, technical appraisal, approval and end-of-life treatment. The laboratory should have end-of-life management operation documents, should be provided for the end-of-life process of instruments and equipment.

2. End-of-life conditions

Instruments and equipment with one of the following conditions can apply for scrapping.

(1) high failure rate can not be repaired after repeated maintenance.

(2) the technical performance of instruments and equipment to reduce the maintenance still can not meet the original technical indicators, resulting in test results are wrong, can not be downgraded to use.

(3) Instruments and equipment aging, can not be repaired, does not have the value of use.

(4) Maintenance costs are too high and do not have maintenance value.

(5)Failure of testing or calibration, and cannot be repaired.

(6)Damaged due to accidents and cannot be repaired.

(7) Long service life (such as: more than 10 years), the basic parts have been seriously damaged, after the repair of its technical performance can not meet the measurement requirements.

(8) Serious impact on the environment or the state regulations do not allow the use of should be eliminated.

3. Technical appraisal

End-of-life instruments and equipment should be relevant technical experts to carry out technical appraisal, and detailed description of the appraisal results.

4.Approval

The scrapping of instruments and equipments should be based on the size of the original value of the instruments and equipments to implement a hierarchical approval system, in principle, a single set or batch of instruments and equipments with an original value of more than 100,000 yuan should be reported to the laboratory's higher level of management for approval.

5. Disposal of End-of-life Instruments and Equipment

End-of-life instruments and equipment can be transferred, sold; at the same time, the cancellation of instruments and equipment assets, instruments and equipment account files and other relevant information. For dangerous equipment, such as boilers, pressure vessels, lifting equipment, etc., it is also necessary to apply for cancellation procedures to the relevant management department.

6. Degradation of use

Part of the loss of function or can not operate normally, but the main function can still meet the needs of the testing work, measurement and verification results do not meet the original provisions of the use of grade can be downgraded according to the actual situation. Degraded use of instruments and equipment should be clearly marked and explained.