English 
Views: 0 Author: Zayn Publish Time: 2022-04-15 Origin: Site
Outline
1. Disinfection and sterilization method
2. UV disinfection and sterilization applications
3. Indicator requirements for UV disinfection and sterilization products
4. UV disinfection and sterilization dose requirements
6. Photochemical and biological effects of ultraviolet radiation on humans
In our life, there are many ways to sterilize. You must be wondering how these methods are applied. Hope the following content can help you.
There are many kinds of disinfection methods in our life, the following four tables show us the role of different disinfection methods and disinfection tools.
Table 1 Disinfection methods and levels of action-Suntech
Levels of action | Definition | Disinfection method |
Sterilize | A method by which all the above microorganisms (including bacterial spores) can reach a guaranteed level of sterilization. | Thermal sterilization, ionizing radiation sterilization, microwave sterilization, plasma sterilization and other physical sterilization methods, and sterilization with formaldehyde, glutaraldehyde, ethylene oxide, peracetic acid, hydrogen peroxide and other disinfectants method |
High level disinfection | It can kill various microorganisms and kill bacterial spores to achieve a disinfection effect. Such disinfection methods should be able to kill all bacterial propagules (including Mycobacterium tuberculosis), viruses, fungi and their spores and most bacterial spores. | Heat, electric radiation, microwave and ultraviolet rays, etc., as well as the use of chlorine, chlorine dioxide, peracetic acid, hydrogen peroxide, bromine-containing disinfectants, ozone, ozone, dibromohydantoin and other methyl hydantoin compounds and some Disinfection method of compound disinfectant and other disinfection factors |
Intermediat level disinfection | Disinfection method that can kill and remove various pathogenic microorganisms other than bacterial spores | Ultrasound, iodine-based disinfectants (iodine, tincture of iodine, etc.), alcohols, alcohols and chlorhexidine compounds, alcohols and quaternary ammonium salts (including double-chain quaternary ammonium salts) compounds, phenols and other disinfectants method of disinfection |
Low level disinfection | Chemical disinfectants that can only kill bacterial propagules (except mycobacteria) and lipophilic viruses, and mechanical sterilization methods such as ventilation and washing | Single-chain quaternary ammonium salt disinfectants (benzalkonium bromide etc.), biguanide disinfectants such as chlorhexidine, plant disinfectants and mercury, silver, copper and other metal ion disinfectants for disinfection methods |
Liquid chemical disinfectant | Glutaraldehyde sterilant | Irritating to skin and mucous membranes |
Peracetic acid | Corrosion-resistant articles, environment and skin, etc. (corrosive to metals, bleaching to fabrics) | |
Hydrogen peroxide | Disinfection of contact lenses, heat-labile plastic products, tableware, clothing, drinking water and air, etc. and oral gargle, shell wound cleaning | |
Dibromodimethylhydantoin (dibromohydantoin) | Disinfection of water, tableware, tea sets, fruits, vegetables, etc. | |
Carbon dioxide | Medical and hygiene, food processing, table (tea) utensils, drinking water and environmental surfaces, etc. (corrosive to metals) | |
Chlorine Disinfectant | Meal (tea) utensils, environment, water, foci, etc. | |
Ethanol | Skin, environmental surfaces and medical devices, etc. | |
Iodophor | Skin, mucous membranes, etc. | |
Guanidine disinfectants | Surgical hand-washing disinfection, surgical site skin disinfection, mucosal disinfection, etc. | |
Quaternary ammonium salt disinfectant | Disinfection of skin and mucous membranes, disinfection of environmental items | |
Acid oxidation potential water | At present, it is mainly used for disinfection of water, skin and mucous membranes, and can also be used for disinfection of tableware, fruits and vegetables, and surfaces of items. | |
UV disinfection | UV disinfection lamp UV Sterilizer | Indoor air, surfaces and water and other liquids |
Low temperature steam formaldehyde gas disinfection | Formaldehyde disinfection and sterilization box (formalin, paraformaldehyde) | It has a killing effect on all microorganisms, and can be used for disinfection and sterilization. No damage to the product (carcinogenic effect, not suitable for indoor air disinfect) |
Ethylene oxide gas extinguishing bacteria | Closed ethylene oxide sterilizer | No damage to sterilized items and light penetration, for e.g. Electronic instruments, optical instruments, medical instruments, books, articles Pieces, fur, cotton, chemical fiber, plastic products, wood products, Ceramic and metal products, endoscopes, dialyzers and disposable Medical supplies, etc. (flammable, explosive, and toxic to humans) |
Ozone | / | Water, surface, air |
The following table is our commonly used disinfection and sterilization methods and scope of application, you can choose a suitable one according to the environment you want to disinfect.
Table 2 Disinfection products and methods-Suntech
Disinfection and Sterilization Methods | Corresponding disinfection products/methods | Scope of application |
Pressure steam sterilization | Pressure steam sterilizer | Items and equipment resistant to high temperature and humidity Cannot be used in oils and powders such as Vaseline |
Dry heat sterilization | Cauterize dry heat sterilizer | No damage, no deterioration, no evaporation of items at high temperatures Instruments that are not resistant to humidity and heat Sterilization of items that cannot be penetrated by steam or gas, such as glass, Products such as grease, powder and metal |
Decontamination | Water cleaning Cleaner/Detergent Enzyme Cleaner | Light pollution, no organic pollution, smooth surface items Detergents with pH<7 are mainly used for the cleaning of inorganic dirt; Detergents with pH>7 are mainly used for organic dirt such as blood, Cleaning of fat and feces (the main choice for metal instruments is weak alkaline detergent) Heavy pollution, especially organic pollution, article structure Cleaning of complex surfaces and matte items |
Precautions for UV disinfection and sterilization applications:
2.1 It can kill various microorganisms, including bacterial propagules, spores, mycobacteria, viruses, fungi, rickettsia and mycoplasma, etc. All surfaces, water and air contaminated by the above microorganisms can be disinfected with ultraviolet rays.
2.2 The penetrating power is weak and can only kill directly irradiated microorganisms. Therefore, the disinfection part must be fully exposed to ultraviolet rays during disinfection.
2.3 When using ultraviolet rays to sterilize rough surfaces such as paper and fabric, the irradiation time should be appropriately extended, and both sides should be irradiated.
2.4 When killing microorganisms protected by organic matter, the irradiation dose should be increased. Suspended particles in air and water can also affect disinfection.
2.5 The suitable temperature range is 20°C to 40°C. If the temperature is too high or too low, the disinfection effect will be affected. The disinfection time can be appropriately extended. When used for air disinfection, the relative humidity of the disinfection environment should be lower than 80%. Otherwise, the irradiation should be appropriately extended time.
UVC: Disinfection and sterilization applications
Ultraviolet germicidal lamp: a light source with a peak wavelength of ultraviolet radiation of 253.7 nm.
UVB: It has a great impact on the human body. Appropriate irradiation can treat and prevent rickets. Long-term irradiation may also damage the skin and eyes, and even cause diseases such as skin cancer, cataracts, and decreased immune system function.
UVA: weak biological effect, mainly pigmentation effect.
3.1 Ultraviolet Disinfection (Bactericidal) Lamps – Low Pressure Mercury Lamps
For better understanding, let us have a look on the explanation of the noun.
– Ultraviolet radiation efficiency: the conversion efficiency of input electric power to ultraviolet sterilization effective radiation (%)
– UV irradiance: UV germicidal effective radiation per unit area (μW/c㎡)
– UV radiation flux maintenance rate and lifetime: the decay of UV germicidal effective radiation over time
– Ozone production rate: the ratio of the amount of ozone produced per unit time to the lamp power (g/kW h)
Irradiance μW/c㎡
Sterilization and disinfection dose μJ/c㎡ = μW s/c㎡
– Ultraviolet radiation efficiency: the conversion efficiency of input electric power to ultraviolet sterilization effective radiation (%)
(Low pressure mercury lamp below 65W, range 10% ~ 23%)
Table 3 UV radiation efficiency-Suntech
Nominal power range W | UV radiation efficiency of the lamp% | ||
Double ended lamp | single ended lamp | Self-ballasted lamps | |
＜9 | 12 | 12 | 10.2 |
9~17 | 18 | 16 | 13.6 |
≥18 | 23 | 20 | 17 |
– UV irradiance: UV sterilization effective radiation per unit area (μW/c㎡) (measured at a distance of 1m)
Table 4 and table 5 show the parameters of the double-tube type, and the data of the four-tube, multi-tube, square and ring lights are evaluated according to 90% of the specified values in the table.
Table 4 Nominal power and double-ended lamp UV irradiace-Suntech
Nominal power/W | 4 | 6 | 8 | 13 | 15 | 18 | 30 | 36 |
Double-ended lamp UV irradiance/ | 11 | 17 | 22 | 35 | 50 | 62 | 100 | 135 |
Table 5 Nominal power and single-ended lamp UV irradiance-Suntech
Nominal power/W | 7 | 9 | 11 | 18 | 24 | 36 | 55(TS) |
Single-ended lamp UV irradiance | 18 | 28 | 40 | 52 | 100 | 150 | 185 |
Note: The values in Table 4 and Table 5 are the parameters of double-tube lamps, and the data of four-tube, multi-tube, square and ring lamps are to be determined. | |||||||
Not less than 93% of the specified value
Single-ended UV lamp rating: 24W: 94 μW/c㎡ ; 36W: 147 μW/c㎡ ; 55W: 170 μW/c㎡ ;
(Source: GB 28235-2011 Safety and Hygiene Standard for Ultraviolet Air Sterilizers)
Ordinary straight tube low-pressure mercury UV disinfection lamp >30W: ≥90μW/c㎡; >20W: ≥60μW/c㎡; 15W: ≥20μW/
(Source: "Disinfection Technical Specifications")
High-intensity ultraviolet disinfection lamp 30W:>170μW/c㎡; 11W:>40μW/c㎡
Ordinary straight tube low pressure mercury UV disinfection lamp (30W): ≥70μW/c㎡
High-intensity ultraviolet disinfection lamp: ≥200μW/c㎡
(Source: GB 15981-1995 Evaluation Methods and Standards for Disinfection and Sterilization Effects)
– UV radiation flux maintenance rate and lifetime: the decay of UV germicidal effective radiation over time
2000 h maintenance rate ≥ 85 %
The average life is not less than 5000h, and the maintenance rate at the end of life is more than 65%
(Source: GB/T 19258-2012 Ultraviolet Germicidal Lamp)
The irradiance value of the UV lamp (30W) should be ≥ 70 μW/c㎡
(Source: GB 15982-2012 Hospital Disinfection and Hygiene Standard)
The time for the irradiance value of ultraviolet lamp (≥30W) to decrease by 70 μW/cm2≥1000h
The time for the irradiance value of ultraviolet lamp (<30W) to decrease by 70% of the initial value is more than 1000h
(source: "Technical Specification for Disinfection")
– Ozone production rate: the ratio of the amount of ozone produced per unit time to the lamp power (g/kW h)
The initial ozone output rate of the ozone-free lamp should not be higher than 50 mg/kW h
(Source: GB/T 19258-2012 Ultraviolet Germicidal Lamp)
·Ozone production <1mg/h
(Source: "Disinfection Technical Specifications")
·The ozone concentration produced by low ozone UV lamps should not exceed 0.3 mg/m
·The ozone concentration of the working environment of the ozone-generating disinfection equipment is < 0.16 mg/m2
(Source: GB 15982-2012 Hospital Disinfection and Hygiene Standard)
·Others: The average maximum allowable ozone concentration in 1h is 0.1 mg/m2
(Source: GB/T 18202-2000 Sanitary Standard for Ozone in Indoor Air)
3.2 UV Air Sterilizers – Cabinet/Hanging/Mobile – Low Ozone UV Lamps
– Indicator requirements for ultraviolet disinfection (sterilization) lamps
– UV leakage: the leakage measured at 30 cm does not exceed 5 μW/c㎡
– Ozone leakage: 1 h average maximum allowable ozone concentration of 0.1 mg/m
– Circulating air volume: not less than 10 times the applicable volum
– Applicable volume: not less than 30 m
(Source: GB 28235-2011 Safety and Hygiene Standard for Ultraviolet Air Sterilizers)
– To kill general bacterial propagules: the irradiation dose should reach 10 000 μW.s/c㎡
– Kill bacterial spores: should reach 100 000 μW.s/c㎡
– Kill viruses: between bacterial propagules and spores
– Killing fungal spores: higher than bacterial spores, sometimes irradiating to 600 000 μW.s/c㎡ (generally pathogenic fungi are less resistant to UV rays than bacterial spores)
– Kill unknown target microorganisms: not less than 100 000 μW.s/c㎡ (Source: "Disinfection Technical Specifications")
– To kill coliform bacteria: should reach 20 000 μW.s/c㎡
– Kill Bacillus subtilis var. black spores: should reach 100 000 μW.s/c㎡
(GB 15981-1995 Evaluation methods and standards for disinfection and sterilization effects)
– direct irradiation method
·Indoor unattended conditions, suspended or mobile
·The number of UV disinfection lamps installed indoors (30W UV lamps, with an intensity of >70μW/c㎡ at 1.0m) is an average of not less than 1.5W per m, and the irradiation time is not less than 30min
– Indirect irradiation method
·Preferred high-intensity UV air sterilizer
·Generally, it can be sterilized after 30 minutes of starting the disinfection.
(Source: "Technical Specification for Disinfection")
– Intra-water exposure or water-external exposure
– The thickness of the water layer should be less than 2 cm
– Determine the water flow speed according to the intensity of the UV light source
(Source: "Technical Specification for Disinfection")
– Microbial killing test: Staphylococcus aureus (ATCC 6538), Escherichia coli (8099), Pseudomonas aeruginosa (ATCC 15442), Bacillus subtilis var. niger (ATCC 9372), Staphylococcus albus (8032, when air sterilized) bacteria and their spores and fungal suspensions (source: "Technical Specifications for Disinfection")
– Surface disinfection indicator bacteria: Escherichia coli ( 8099 ), Bacillus subtilis var nigra ( ATCC 9372 ) (Source: GB 15981-1995 Evaluation Methods and Standards for Disinfection and Sterilization Effects)
– Air disinfection effect test: the killing rate of Staphylococcus albicans (8032 strains) ≥ 99.90% or the extinction rate of natural bacteria ≥ 90%, the disinfection time should not exceed 3 hours
(Source: GB 28235-2011 Safety and Hygiene Standards for Ultraviolet Air Sterilizers Note: It is mentioned in "Technical Specifications for Disinfection" that the disinfection effect is generally achieved within 30 minutes)
– Microbial killing effect test (highest loading): Staphylococcus aureus (ATCC 6538), Escherichia coli (8099), Pseudomonas aeruginosa (ATCC 15442), Bacillus subtilis var. black (ATCC 9372) spores, Candida albicans (ATCC 10231), Mycobacterium chelena subsp. abscessus (ATCC93326) and other suspensions and poliovirus suspensions
(Source: "Technical Specification for Disinfection")
6.1 Hygienic standard limits
The following standard limits refer to the measured values in protective equipment.
UVB: Daily exposure should not exceed 0.26″uW/cm² (or 3.7mJ/cm² ):
UVC: Daily exposure should not exceed 0.13uW/cm² (or 1.8mJ/cm² );
Welding arc light, the daily exposure should not exceed 0.24uW/cm² (or 3.57mJ/cm² )
UVB, must not exceed at any time 1 uW/cm³(or 14.4mJ/cm² )
UVC: must not exceed any time 0.5 uW/cm³(or 7.2mJ/cm² )
Welding arc light: no more than 0.9μWcm² at any time(or 12.9mJ/cm² )
Historical hazard to the skin and eyes to observe the original value
The exposure limit of UV radiation that is incident on unprotected skin and filled with UV radiation is only applicable when the exposure time is within 8 hours. Radiation that lasts for more than 8 hours in any day is not considered here, and the effective radiation compliance value is 30 J·m²',
To protect eyes or skin from UV radiation produced by broadband spectrum light sources. The effective integrated spectral cell degree E of the light source shall not be defined by the formula.
(1) Q: How much is the ultraviolet irradiance of sunlight?
Answer: UVC sunlight is present, but it cannot reach the surface; UVB is 10% that can reach the surface; UVA exists on the surface, but the spectral range of sunlight is very wide, so the total UV is about 4%- 5% range.
To get clear UV radiation in different months, let s have a look on table 6.
Table 6 Ultraviolet rays account for monthly value of total solar radiation
Month | National UV radiation as a percentage of solar radiation |
January | 4.25 |
February | 4.32 |
March | 4.33 |
April | 4.68 |
May | 4.98 |
June | 5.00 |
July | 4.90 |
Augest | 5.04 |
September | 4.69 |
October | 4.51 |
November | 4.29 |
December | 4.16 |
(2) Q: Does the average lifespan of UV lamps not less than 5000h end when the light decays to 50%?
Answer: The average lifespan is not less than 5000h. The requirement is that the maintenance rate of ultraviolet radiation flux at the end of life is not less than 65%.
(3) Q: When the light decay reaches below 65%, is the disinfection effect also reduced accordingly?
Answer: You can't absolutely say this, because the disinfection measurement is the judgment of the disinfection effect. If the light decays, the disinfection effect can be achieved by prolonging the disinfection time.
UV products from Suntech you may be interested in:
Please click on the images in the table below to view product details.
| Wave- length(nm) | Radiant flux | Radiant flux | Dimension L*W*H(mm) |
Germicidal UVC LED Bar Module |
| 265-285nm | 15-20mw | 280*60mm |
250nm 254nm 255nm UVC Disinfection LED Module |
| 250-255nm | 300mw/m | 280*40mm |
UVC Disinfection LED Module
|
| 265-278nm | 20mw | 240*40mm |
UVC LED Bulb 265nm 275nm Germicidal Light |
| 265-278nm | 900/1350mw | 135×200mm |
Germicidal UVC LED Strip |
| 265-278nm | 90mw | / |
High Power UVC LED Chip |
| 270-280nm | 380.87 mW | 45*65mm |
Deep UVC LED Chip Diode |
| 254nm 255nm | 10mw ~ 15mw | 36*36mm |
Far UVC Led Chip Strip Light |
| 207nm 220nm 222nm | 2.5mw | 65*45mm |
Far UVC Led Light |
| 207nm 220nm 222nm | 2.5mw | 36*36mm |
Far UVC 222nm LED Tube Light
|
| 222nm | / | 28*120mm |
UVC articles you may be interested in:
Knowledge and application of UVC ultraviolet rays
Frequently Asked Questions About UVC
Top 10 Things to Know Before Buying a UV Black Light LED Strip
UVA UVB and UVC Radiation - Everything You Need to Know
What is UV-C
UVA VS UVB VS UVC Light
TO UPGRADE TO THE BEST LIGHT YOU CAN BUY?
↓↓↓
