UV disinfection plays an important role in the COVID-19 outbreak. In previous articles, we have discussed the application of UV disinfection in hospitals, water plants, etc. Today we discuss the application of UV disinfection in our daily life – elevators.
Let’s dive right in now, and you can click on the question that interest you,
1 The importance of elevator prevention and control
To prevent and control COVID-19 pneumonia, it is inevitable to ride in elevators when going to work, shopping, and medical appointments, etc. Epidemic prevention in elevators is a top priority. It is important to study the prevention and control of the epidemic in elevator.
2 The source of virus infection in the elevator transmission channels
- Patient coughing and sneezing, droplet transmission.
- Patient touches a button, contact transmission.
- Carrying household waste such as tissue used by the patient, contact transmission.
3 Elevator disinfection method
“The Pneumonia Treatment Protocol for COVID-19 Infection” states that the virus is sensitive to ultraviolet light and heat and that the virus can be treated at 56 °C for 30 min, with ether, ether, peroxyacetic acid and chloroform. 75% ethanol, chlorinated disinfectants, peroxyacetic acid and chloroform are all lipid solvents The virus can be effectively inactivated.
It is not advisable to use high-temperature disinfection in elevator cabs. Two methods are recommended to kill the virus: ultraviolet light and disinfectants.
1) UV disinfection method
The UV used for disinfection is C-wave UV, and the UV lamps used for disinfection can produce UV rays with irradiance values that meet national standards. UV can kill all kinds of microorganisms, and both water and air can be disinfected with UV. UV irradiation energy is low, penetration is weak, and can only kill directly irradiated microorganisms, so disinfection must fully expose the disinfection site to UV light, need to adjust the location of the UV disinfection lamp in the elevator, such as the top near the button.
Factors affecting UV irradiation intensity include the impact of voltage on UV irradiation intensity and ballast impact. Due to the lack of voltage from time to time, voltage fluctuations on the UV disinfection lamp irradiation intensity have a significant impact, different ballasts, lamp life, etc., on the UV disinfection lamp irradiation Intensity also has an impact on the need to properly adjust the disinfection time.
After contact with microorganisms, the active chemical groups of the disinfectant itself cause chemical reactions that lead to damage to functional structures (proteins, DNA, and cell membranes) of microorganisms. And cell membranes, etc.) are damaged and rendered inactive, thus achieving the goal of killing microorganisms. The purpose of killing microorganisms is to kill them.
4 Risk of disinfection in elevators
1) Passenger Health Risks
If there are passengers in the elevator, the above disinfection process can be harmful to their health to varying degrees.
A. Ultraviolet light
When the UV lamp irradiation, if the human eyes, skin in the UV Under the UV light, it can cause burns, erythema, UV ophthalmic or skin allergy, etc. In some reports, some people did not take appropriate protective measures, purple In some reports, due to the lack of appropriate protective measures, the UV rays have caused different degrees of skin and eye damage.
The main health hazards of ultraviolet radiation are ① Skin erythema and peeling reaction. Ultraviolet radiation can burn the skin, manifesting as skin flushing, burning pain, serious redness can form. Burning pain, serious can form red spots, peeling skin. ② Electrophotographic ophthalmic. By the purple external radiation, can cause keratitis, conjunctivitis, etc., the hospital for sterilization The hospital is used for sterilization of ultraviolet light has a bactericidal effect, easy to damage the eyes and skin.
Ozone is produced by ultraviolet light, and there are several types of UV disinfection lamps as follows. ① Ordinary straight tube hot cathode low-pressure mercury ultraviolet disinfection lamp. Lamp tube using quartz British glass or other glass with a high UV transmission rate, this lamp can produce ozone. ② High-intensity UV disinfection lamps. ③ Low ozone UV disinfection lamps. Also, a hot-cathode low-pressure mercury lamp, either straight or H-shaped. Ozone production is very low. ④ High ozone UV disinfection lamps. This lamp’s ozone yield is large. It is advisable to use low ozone UV disinfection lamps in elevator cabs to avoid the danger of ozone to passengers.
The risk of accidental ingestion of disinfectants is small, but exposure or inhalation may cause poisoning or adverse reactions, which can cause acute or chronic pathological changes in humans through the respiratory intake. The degree of poisoning and its manifestations vary and can be divided into three categories: acute poisoning, subacute poisoning, and chronic poisoning according to the speed of response to poisoning symptoms. The condition of disinfectant chemical poisoning is critical and complex. Such as peroxyacetic acid disinfectants in large doses for a long time inappropriate use can lead to a number of adverse reactions in humans, serious will cause acute eczema, contact dermatitis, induced bronchial asthma, allergic rhinitis, acidic eye conjunctive membrane damage, etc. Most commonly used disinfectants are of low or moderate toxicity, but Since most disinfectants are used diluted, they are generally not very toxic. Most disinfectants have a significant irritating effect on the skin and mucous membranes. Disinfectants can cause inhalation pneumonia, chemical pneumonia, and even chemical pulmonary edema when inhaled through the respiratory tract. Strong oxidizing disinfectants such as chlorine dioxide, chloramine, and sodium hypochlorite may cause methemoglobinemia. A few disinfectants such as Chloramine, chlorine dioxide, peroxyacetic acid, and Lysol may cause hemolysis.
Disinfectants mostly cause only minor respiratory irritation when used normally, as required. A few people may experience eye irritation. Skin and mucous membrane Immediately after contact with highly concentrated solutions, local erythema, edema, pa pules, etc. appear at the contact site. Immediately after contact with the highly concentrated solution, local erythema, edema, pa pules, etc., followed by blisters, vesicles, ulcers, self-conscious Pain, burning sensation, or itching. Contact with iodine, alcohols, aldehydes, and other disinfectants can cause allergic dermatitis.
Allergic dermatitis can occur after contact with disinfectants containing iodine, alcohols, aldehydes, etc. Allergic dermatitis can occur after exposure to disinfectants containing iodine, alcohols, aldehydes, etc. When large amounts of chlorine gas are inhaled, there are obvious symptoms of respiratory irritation, such as cough, a small amount of sputum, chest tightness, shortness of breath, cyanosis, etc. In severe cases, chemical pulmonary edema may occur, and even acute In severe cases, chemical pulmonary edema and even acute respiratory distress syndrome may occur.
Chlorine dioxide, chloramine, and sodium hypochlorite can cause methemoglobinemia. When the level of methemoglobin in the blood exceeds 1%, it can When the level of met hemoglobin in the blood exceeds 1%, dizziness, headache, weakness, chest tightness, and cyanosis may occur. Chloramine, chlorine dioxide, peroxyacetic acid, Lysol, etc. can cause hemolysis, hemoglobin In serious cases, renal failure may occur.
Inhalation of low concentrations of ozone can cause headaches, dizziness, lack of concentration headache, dizziness, lack of concentration, loss of vision, and other symptoms. Ozone can make the peripheral blood vessels dilate, causing blood pressure to drop.
2) Elevator Safety Operation Risks
After adding disinfection measures, the following elevator safety operation risks may arise. (1) The impact of UV lamp electricity on elevator electricity. The elevator is designed to use electricity without considering the UV lamp electricity factor, which may be overloaded. (2) The influence of picking up control signals from the elevator control system. (1) Pick up the control signal from the elevator control system to control the UV disinfection lamp, which may cause the control circuit failure. ② UV lamp leakage may trigger control circuit failure. (3) Effect of disinfectant on passengers in the elevator during a power failure or malfunction or protection. In case of power failure or malfunction or protection, the elevator is closed and passengers cannot enter or leave, and the disinfectant affects the passengers inside the car for a long time. (4) Risk of using energy-saving circuits for UV disinfection lamps. Many elevators automatically enter the energy-saving state when no one is using the elevator. It is envisioned that the elevator will automatically turn on the UV disinfection lamp when it enters the energy-saving state. ① Failure of the energy-saving circuit triggers the UV disinfection lamp to turn on accidentally and accidentally radiate UV light to passengers inside the car. ② If passengers are not operating the elevator, the elevator thinks that no one is using it will automatically enter the energy-saving state, triggering the UV disinfection lamp to turn on accidentally and accidentally radiating UV light to the passengers inside the car. (5) Liquid disinfectant risk. Liquid disinfectant flows out of the car and short-circuits the elevator safety circuit or control circuit, causing elevator safety risks. (6) Other agnostic safety risks. The effect of long-term disinfection in the elevator car on the safety circuit and control circuit is not yet known, and the existence of other safety risks cannot be avoided.
5 Recommendations for elevator disinfection
1) Recommendations for elevator prevention and control under the COVID-19 pneumonia outbreak
COVID-19 pneumonia may be transmitted through elevators, prevention, and control virus methods simply wiping the buttons are not sufficient, and it is recommended to add UV disinfection or disinfectants. UV light or disinfectants may trigger passenger and elevator safety risks, and care should be taken to regulate the operation, including at least: (1) UV light or disinfectant disinfection, concentration, dose, time, and interval to be studied and developed by medical experts. (2) Select low ozone medical UV disinfection lamps. (3) Use UV disinfection to ensure irradiance and time. (4) Use ultraviolet lamp disinfection, prohibit personnel from entering the elevator. (5) Avoid direct exposure of the operator’s skin and eyes to UV light. Skin and eyes directly under UV light. Wear sunglasses, a head covering that covers the entire face and neck, and Wear long-sleeved, long-pants work clothes and gloves to reduce UV damage to the skin. (6)After disinfection of UV light, ventilation before entering. (7) Use disinfectant to ensure concentration and time. (8) After using the disinfectant, ventilate and remove the disinfectant. Air to remove the disinfectant and measure the drug in the air, not exceeding the specified maximum allowable concentration. (9) Be careful that the liquid disinfectant does not flow outside the car and impacts the safety of the elevator.
6 Suggestions for prevention and control of automatic disinfection in elevators
Carry out scientific and technological projects on automatic disinfection in elevator cabs to ensure both disinfection effects and elevator safety and passenger safety without affecting passenger use. To eliminate risks, automatic disinfection should have the following features: (1) Automatic determination of the presence or absence of personnel in the elevator. (2) UV disinfection device suitable for the elevator. (3) A disinfectant suitable for the elevator to avoid the escape of liquid. (4) Spraying device suitable for the elevator. (5) Infrared detection safety interlock device for personnel entering the elevator to avoid automatic device failure. (6) One-touch cut-off function. (7) Warning in the elevator before disinfection, with cut-off key, so that the disinfection device can be cut off if there are passengers. (8) The disinfection method is automatic, and the manager can intervene manually according to the epidemic situation. (9) Disinfection frequency can be set. (10) Ventilation after disinfection is finished before the elevator can operate.
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