Background

Since the SARS epidemic in 2003, people have generally realized the importance of hands cleaning. Hand washing is a good way to keep your hands clean (and certainly the right way), but in some cases, we may not have facilities and soap for hand washing. In this case, who recommends using alcohol hand rub instead of hand Wash1.

There are three key points discussed in this article:

1. Alcohol hand sanitizer instead of hand washing?

2. Furniture disinfection

3. Other household disinfection methods

Alcohol hand sanitizer instead of hand washing?

The effective component of alcohol hand rub solution is ethanol or isopropanol, and when the alcohol concentration reaches 60-80%, the bactericidal efficacy is the best 2. As alcohol is a colorless liquid, its concentration cannot be estimated by naked eyes, so it is necessary to test to know whether the sample can effectively sterilize. In addition, it should be noted that alcohol is a volatile liquid. If the container is not properly covered, the alcohol concentration will decrease with time, and finally affect the germicidal efficacy.

Health risk

Because alcohol disinfectant can effectively kill bacteria, it has become a necessary consumable for the public since the outbreak of the epidemic. However, the quality of alcohol products sold on the market is poor.

In the past, Hong Kong Customs has seized some inferior alcohol products on the market, some of which are inconsistent with the label, some contain excessive methanol, some even contain only methanol. For these Eucalyptus pieces, the customs mainly cited the commodity description Ordinance and the consumer goods safety ordinance to investigate the relevant persons. Among them, the commodity description Ordinance mainly aims at whether the alcohol content or capacity of the product conforms to the label, while the Consumer Goods Safety Ordinance requires whether the products sold on the market conform to the reasonable safety level. There are no relevant laws in Hong Kong on what is the safe methanol content, but we can refer to the safety standards for products applied on the skin in other places. For example, the mainland's cosmetics safety technical specification stipulates that the methanol content in cosmetics shall not be more than 0.2%; in addition, the EU's cosmetics (EC) No 1223 / 2009), methanol is only used for denaturation of ethanol or isopropanol, and the content shall not be more than 5%. As for other types of cosmetics, methanol is not allowed. Because methanol is colorless and tasteless, it is difficult for ordinary people to detect the difference of the product, so the safest way is to send the product to the laboratory for analysis.

Disinfection home furnishing

In response to the epidemic, in addition to personal hygiene, now many people will strengthen the cleaning of home environment at the same time. As early as in the SARS era, the Hong Kong Department of health has publicized to the public that 1:99 bleach can be used for general household cleaning. Until recently, this proposal has not changed.

Javelle water

The bactericidal component of bleaching water is hypochlorite ion, which can kill pathogens quickly. However, the recommended sodium hypochlorite content of bleaching water by Hong Kong Health Department is 5.25%. The biggest problem with the proposal of using 1:99 bleach is the sodium hypochlorite content in the bleach before dilution, which will vary according to different brands. If the user wants to know the concentration of sodium hypochlorite in the bleached water, he may need to refer to the label on the product; and the manufacturer who intends to sell the bleached water may also want to consider sending the product for inspection, and then marking the content of sodium hypochlorite on the label.

In addition to the concentration requirements, the national health and Health Commission issued the notice on printing and distributing the guidelines for the use of disinfectants 4. The notice specifies that the correct use method of chlorine containing disinfectant (including 84 disinfectant and bleach) is to wear gloves and masks, dilute in a certain proportion and avoid direct contact. There are more ways to use other kinds of disinfectants in the notice. Citizens can refer to relevant contents to disinfect their homes, individuals and articles.

Other household disinfection methods

In addition to some officially recommended disinfection methods, there are also some products on the market that claim to be effective in disinfection, so as to provide more ways for the public to maintain environmental health. Due to the wide variety and different functions of this kind of products, here we take two more scientifically based products to discuss.

Ultraviolet germicidal lamp

As early as more than 100 years ago, people have found that ultraviolet has bactericidal function. Since then, it has been convenient for people to use ultraviolet rays for disinfection and sterilization. In recent years, the technology of ultraviolet sterilization has been commercialized, with various types of products, some of which are small ones for disinfection of daily necessities, some of which are relatively large ones for disinfection of home environment.

Although ultraviolet has bactericidal function, not all ultraviolet rays can effectively kill bacteria. Only UV with a wavelength between 240-280nm (in the range of UVC wavelength) has the best bactericidal efficacy due to its maximum destructive power to biological genetic material. And the ultraviolet light that mercury lamp produces is in this range almost 7, so it is very suitable for ultraviolet disinfection and sterilization.

UV does not retain chemicals like fungicides, which is its advantage. However, UV can only kill bacteria 6 on the surface or in the air, which is powerless for the covered surface. In addition, UVC is also harmful to human body. If you often irradiate it, it will lead to inflammation of conjunctiva or even skin cancer. 8. You must leave the site when you use it. Therefore, if the product has timing switch or remote control switch function, it will be ideal.

ozone generator

Ozone is a molecule with three oxygen atoms. It is a blue gas at room temperature. It can kill bacteria because of its strong oxidizing power. The use of ozone as a disinfectant is not a new thing, because odor is often used in the disinfection process of water. In 2003, the U.S. Food and Drug Administration (FDA) also approved ozone procedures for disinfection of reusable medical devices 6 (only following certain controlled procedures). In addition, studies have also shown that influenza A virus loses its activity after 210 minutes in 10 ppm (V / V) ozone. The advantage of ozone disinfection is that ozone will decompose slowly soon after it is produced (the ozone half-life is up to 25 hours; if the ventilation is good, the ozone concentration will be reduced by half every more than 30 minutes by 10), and dissipate after a period of time. However, ozone is a toxic gas, if inhaled excessively, it will cause respiratory system damage.

Because ozone has bactericidal efficacy, some civil ozone products appear on the market, and claim to be able to effectively kill pathogens in the environment and prevent infection. Depending on the use of these products, they can be roughly divided into two categories: closed space and open space. The enclosed space here refers to the small closed space of shoe cabinet, refrigerator, wardrobe, etc.; while the open space refers to the large space of toilet, kitchen, bedroom, etc. and the space for people to enter and exit. For products used for confined space use, if the ozone produced by products can be confined to a specific space and reach an effective concentration, such products may really play a role, and at the same time will not pose a great problem to other people in the room; however, for products used for open space, the effectiveness of products is affected by many factors (such as product efficiency, indoor ventilation 12. It is difficult for the user to have enough knowledge and ability to control the indoor ozone to achieve the desired effect and ensure the safety of the user. If you have children or asthma, emphysema and other high-risk people in your family, 11 these products will become a little dangerous to use. So readers must think twice before buying or using ozone sterilizer.