Medical ultraviolet disinfection lamp is a kind of mechanical equipment that can sterilize, and the utilization rate in seeing a doctor is very high. Ultraviolet sterilization lamp, also known as ultraviolet sterilization lamp, ultraviolet sterilization lamp uses ultraviolet rays from mercury lamps to maintain the sterilization and disinfection effect. Do 99%~99.9%.

Types of Medical Ultraviolet Disinfection Lamps

Later, according to different application environments, different types of ultraviolet sterilizers are applied to realize the application scheme of disinfection and isolation in the environment of new coronavirus infection.
Ultraviolet sterilization is actually medical ultraviolet radiation, which can kill all viruses in 10 minutes. The disinfection cabinet and germicidal lamp at home actually have similar functions.

National standard for the intensity of ultraviolet germicidal lamps

The UVC band in the ultraviolet rays has the effect of sterilization and disinfection. The ultraviolet rays emitted by the ultraviolet germicidal lamp are UVC short-wave ultraviolet rays. When the ultraviolet germicidal lamp is used for a long time, the attenuation of the light source will occur, so the intensity of the ultraviolet germicidal lamp must be checked regularly.

According to the country: WS/T 367-2012 "Technical Specifications for Disinfection of Medical Institutions", "Technical Specifications for Disinfection in Hospitals" in 2009, and GB19258-2003 for UV germicidal lamps, the power intensity and detection of UV germicidal lamps are related. Require.

The following are the power intensity and testing requirements of ultraviolet germicidal lamps stipulated by national standards:

1. The peak wavelength emitted by the ultraviolet germicidal lamp is 253.7nm, and the ultraviolet light of this wavelength has the sterilization function.

2. The detection can only be started when the intensity is relatively stable after the UV lamp is turned on for 5 minutes.

3. The UVC intensity radiometer must be placed in the vertical center of 1 meter below the germicidal lamp for testing.

4. For new lamps, the irradiation intensity of UV germicidal lamps is greater than 90μW/c㎡ to be qualified.

5. The old lamps in use are less than 70μW/c㎡ as unqualified.

6. Different power UV lamps have different irradiation ratings.

How to judge whether the germicidal performance of the ultraviolet germicidal lamp meets the standard?
Recently, due to the impact of the new coronary pneumonia, "disinfection" has become a high-frequency word in life, and disinfection methods such as 75% alcohol, 84 disinfectant, and hand sanitizer have been mentioned again and again. The latest "Pneumonia Diagnosis and Treatment Plan for Novel Coronavirus Infection (Trial Version 6)" pointed out that "the virus is sensitive to ultraviolet light and heat", and the concept of ultraviolet sterilization and disinfection has become a hot spot nowadays.

As a mutagen, UV light can cause abnormal chemical bond formation between adjacent pyrimidine molecules in DNA or RNA in microbial cells such as bacteria and viruses in a specific wavelength range (mainly UVC200 – 280 nm) and at a high enough dose , hinder the replication of DNA or RNA, thereby causing microbial cell death.
Common ultraviolet sterilization and disinfection belong to irradiation disinfection, just irradiate the ultraviolet germicidal lamp to the items that need to be sterilized, or place the ultraviolet germicidal lamp in the environment that needs sterilization and disinfection. Ultraviolet rays can concentrate very high intensity to kill bacteria and viruses in a short time. It is a pure physical disinfection method without secondary pollution. So, how to judge the effect of ultraviolet disinfection compared with conventional chemical disinfection and heat disinfection?

"Technical Specifications for Disinfection" Ministry of Health (2019 edition) is one of the commonly used standards for evaluating the surface sterilization and disinfection effect of ultraviolet germicidal lamps. function to verify whether its bactericidal performance meets the qualified standard.

irradiance intensity

Ordinary type or low ozone type straight tube UV lamp (30W), the irradiance value of the new lamp should be ≥90μW/cm². For lamps in use, the irradiance value should be ≥70μW/cm². The determination method and qualification standard for multi-tube combination lamps are the same as those for single lamps. For special-shaped (non-straight-tube), high-intensity, or non-30W lamps, the inspection distance and irradiance value eligibility criteria depend on the application and usage of the product. In principle, the irradiance value should not be lower than the irradiance value stated in the product instruction manual, and the sterilization test should be carried out according to its recommended dose [i.e., the irradiance value multiplied by the irradiation time (s)]. Passed the laboratory test. At the same time, 10 lamps are randomly checked for each identification of irradiance intensity, and each lamp is repeated 3 times. The irradiation intensity can be judged as qualified only when the data of each time reaches the standard.

Microbial killing effect

Species evaluated: Staphylococcus aureus (ATCC 6538), Escherichia coli (8099), Pseudomonas aeruginosa (ATCC 15442) Bacillus subtilis black var. (ATCC 9372) spores and other bacteria and their spores and fungi.

When measuring the killing effect of microorganisms, firstly prepare bacteria and their spores and fungal slices according to the method specified in the technical specification, and irradiate them at the designated irradiation position. Irradiation is divided into 3 time groups. The time setting of each group should be able to measure the minimum dose required to kill the test bacteria and their spores and fungi with a logarithmic value of ≥ 3.00, and complete the determination of the viable bacterial culture count of the irradiated samples. .

In the test, a positive control group (bacteria slice control) and a negative control group (medium control) were established at the same time. For the positive control group, put 2 pieces of the batch into test tubes containing 5.0ml PBS respectively, and shake with an electric mixer for 20s or 80 times each. The negative control group was cultured with the same experimental medium or PBS inoculated medium, and the presence or absence of bacterial growth was observed.

The test was repeated 3 times. For the positive control bacterial tablets in each test, the amount of recovered bacteria should be between 5×10⁵cfu/tablet to 5×106cfu/tablet, and the negative control group should grow aseptically. The logarithmic values ​​are all ≥3.00. The irradiation time can be judged as the irradiation time required to pass the disinfection. The irradiation distance of special-shaped (non-straight tube), high-intensity, or non-30W lamps depends on the purpose and method of use of the product.

In addition to the above two items, the amount of ozone produced by the ultraviolet lamp can also affect the sterilization effect and the safety of use, so it is necessary to measure the ozone concentration for comprehensive evaluation. The technical specification points out that the ozone concentration should be stated in the instruction manual, and the ozone concentration generated by the low-ozone ultraviolet lamp should not exceed the safe concentration in the workplace (0.3mg/m³) stipulated by the state.

disinfection rate : 99.9%