Nước rửa tay khô sẽ giúp bạn hạn chế được sự lây nhiễm virus, theo khuyến cáo của nhiều bác sỹ và tổ chức y tế trên thế giới WHO.
Những ngày qua, thấy các chị em thường xuyên than vãn không mua được nước rửa tay khô nên mình xin gửi tới các bạn cách tự pha chế nước rửa tay khô diệt virus theo hướng dẫn của WHO như sau nhé:
WHO đã đưa ra công thức tự pha chế dung dịch rửa tay khô với một số lưu ý, gồm công thức dùng để pha chế 10 lít dung dịch rửa tay, thể tích mỗi lần pha chế không được vượt qua 50 lít.
Hướng dẫn tự làm dung dịch rửa tay khô
Các nguyên liệu chuẩn bị gồm:
– Chai xịt, lọ để chiết dung dịch.
– Bình thủy tinh dung tích 10l.
– Phễu nhỏ.
– Cồn y tế 96%: 8333ml (tác dụng khử trùng).
– Oxy già 3%: 417ml (ngưng hoạt bào tử vi khuẩn bị nhiễm trong dung dịch).
– Glycerin 98%: 145ml (giữ ẩm da tay).
– Nước cất hoặc nước đun sôi để nguội
Lưu ý: các dụng cụ, nguyên liệu bên trên chúng ta mua tại các cơ sở y tế. Cồn y tế có khả năng bắt cháy nên khi tiến hành pha chế cần tránh xa những khu vực lửa, nguồn điện. Rửa sạch các dụng cụ pha chế và có găng tay đeo khi thực hiện.
Các bước làm dung dịch rửa tay khô:
– Đong 8333ml cồn rồi đổ vào bình chưa 10l.
– Tiếp tục đong 417ml oxy già rồi thêm vào bình chứa cồn.
– Đong 145ml glyxerin rồi cho vào bình chứa hỗn hợp trên. Sau khi đổ xong cần tráng bình đong gylxerin bằng nước đun sôi để nguội do dung dịch có tính chất nhớt. Nước tráng bình sẽ đổ vào bình chứa hỗn hợp.
– Đổ nước cất/nước đun sôi để nguội vào bình chứa khi hỗn hợp dung dịch trong bình chạm đến mốc 10l. Vặn nắp ngay để tránh bay hơi.
– Lắc đều bình 10l để trộn đều các dung dịch bên trong bình.
– Chiết dung dịch vừa pha chế sang những lọ nhỏ hơn. Khi chiết xong cần chờ 72 tiếng để các loại vi khuẩn trong bình chiết bị tiêu diệt thì mới sử dụng được.
Vậy là xong rồi đó, bạn thấy có đơn giản không? Hãy bắt tay vào làm thử ngay thôi nào.
Chúc các bạn thành công.
A WHO alcohol-based formulation
10.1 General remarks
The design of a product to be used worldwide has to take logistic, economic and cultural
(including religious) factors into consideration (see also Part I, Section 14).
At present, alcohol-based handrubs are the only products to reduce or inhibit the growth
of microorganisms with maximum efficacy156,256,262,350,359-361.
WHO recommends an alcohol-based formulation for the following reasons:
to benefit from its evidence-based intrinsic advantages: fast acting and broad-spectrum activity, excellent microbicidal characteristics, lack of potential emergence
of resistance;
to overcome the lack of accessibility to sinks or other facilities (including clean
running water or towels in some poor and remote areas) to perform hand cleansing actions that require the use of water (handwashing and hand antisepsis using
a formulation different from a waterless agent);
to improve compliance with hand hygiene by reducing the time required to perform it and the convenience of the method;
to reduce costs: the annual cost of hand hygiene promotion including recourse
to an alcohol-based handrub may not exceed 1% of HCAI costs (see also Part III,
Section 3)362-364.
To achieve a maximum effect and optimal compliance of HCWs with hand hygiene,
products should be easily available, either through dispensers placed close to the point of
care or in small individual bottles for pocket carriage263,359.
Health-care settings currently using commercially-available handrubs, liquid soaps and
skin care products sold in disposable containers should continue this practice, provided that
the handrubs meet recognised standards for microbiological efficacy (ASTM or EN standards) and are well accepted by the HCWs. In health-care settings where these products are
not available or too costly, production of the WHO handrub according to the formulation/s
and methodology suggested below is an alternative.
10.1.1 Suggested composition of alcohol-based formulations for
in-house/local production
The choice of components for the WHO handrub formulations takes into account cost
constraints and microbiological efficacy. Where commercially-available and validated
(ASTM or EN) products are already used and well accepted by HCWs, they should obviously
be regarded as acceptable even if their contents differ from those of the WHO formulations described below. The following two formulations are recommended for preparation
in-house or in a local production facility up to a maximum of 50 litres:
Formulation I
To produce final concentrations of ethanol 80% v/v, glycerol 1.45% v/v, hydrogen peroxide
0.125% v/v.
Pour into a 1000 ml graduated flask:
a) ethanol 96% v/v, 833.3 ml
b) hydrogen peroxide 3%, 41.7 ml
c) glycerol 98% ,14.5 ml
Top up the flask to 1000 ml with distilled or boiled and cooled water and shake the flask
gently to mix the content.
Formulation II
To produce final concentrations of isopropyl alcohol 75% v/v, glycerol 1.45% v/v, hydrogen
peroxide 0.125% v/v:
Pour into a 1000 ml graduated flask:
isopropyl alcohol (with a purity of 99.8%), 751.5 ml
hydrogen peroxide 3%, 41.7 ml
glycerol 98%, 14.5 ml
Top up the flask to 1000 ml with distilled or boiled and cooled water and shake the flask
gently to mix the content.
10.1.2 Method for in-house/local production
10 litre preparations: glass or plastic bottles with screw-threaded stoppers can be used.
50 litre preparations: large plastic (preferably polypropylene, translucent enough to see
the liquid level) or stainless steel tanks with an 80 to 100 litre capacity should be used to
allow for mixing without overflowing.
The tanks should be calibrated for the ethanol/isopropyl alcohol volumes and for the final
volumes of either 10 or 50 litres. It is best to mark plastic tanks on the outside and stainless
steel ones on the inside.
Mixing should be carried out using wooden, plastic or metallic paddles. Electric mixers
should not be used unless “EX” protected because of the danger of explosion.
Preparation
The alcohol for the chosen formulation is poured into the large bottle or tank up
to the graduated mark.
Hydrogen peroxide is added using the measuring cylinder.
Glycerol is added using a measuring cylinder. As the glycerol is very viscous and
sticks to the walls of the measuring cylinder, it can be rinsed with some of the
water to be added and emptied into the tank.
The tank is then topped up to the corresponding mark of the volume to be prepared with the remainder of the distilled or cooled, boiled water.
The solution is mixed by gently shaking the recipient where appropriate (small
quantities), or by using a paddle.
The lid or the screw cap is placed on the tank/bottle immediately after mixing to
prevent evaporation.
For a more detailed production guideline for 10 and 50 litres of both formulations see the
“Guide to in-house/local manufacturing” at www.who.int/patientsafety
After dividing the solution into smaller containers (e.g., 1000, 500 or 100 ml plastic bottles), the bottles should be kept in quarantine for 72 hours. This allows time for any spores
present in the alcohol or the (re-used) bottles to be destroyed by the hydrogen peroxide.
Note: If concentrated alcohol is obtained from local production, verify the alcohol concentration and make the necessary adjustments in volume to obtain the final recommended
concentration.
Labelling of the bottles should be in accordance with national guidelines, but should
include the mention:
antiseptic handrub solution
for external use only
keep out of reach of children
avoid contact with eyes
use: apply about 2 ml to the palm of the hand and rub both hands and fingers,
front and back until dry
formula contents:
Formulation I
Ethanol 80% (v/v), glycerol 1.45% and hydrogen peroxide 0.125%
or
Formulation II
Isopropyl alcohol 75% (v/v), glycerol 1.45% and hydrogen peroxide 0.125%
flammable liquid: keep away from heat and flame.
Special requirements are applicable for the production and storage of the formulations,
as well as the storage of the primary products. The quantity of locally-produced WHO
handrub should not exceed 50 litres, or possibly less if regulated by local and/or national
guidelines and regulations.
Alcohol is the active component and some aspects concerning other components should
be respected. All components should be free of spores [i.e., by treatment with hydrogen
peroxide (H2O2) or commercially by filtering]. While the use of H2O2 autosterilizes the
solution, thus eliminating spores originating from components or reused bottles and thereby
adding an important safety aspect, the use of 3–6% of H2O2 for the production might be
complicated by its corrosive nature and difficult procurement in some countries. Further
investigation is needed to assess H2O2 availability in different countries as well as the possibility of using a stock solution with a lower concentration.
While the chance of ingestion should be reduced by using a bad taste additive such as
methylethylketone (1% in 96% ethanol), this would increase the toxicity of the product in
cases of accidental ingestion, as well as adding costs and problems of availability. For this
reason, no bad taste additive is included in the above formulations. Any further additive to
both formulations should be clearly labelled and non-toxic in case of accidental ingestion. A
colorant may be added to allow differentiation from other fluids, but should not add to toxicity, promote allergy or interfere with the antimicrobial properties (see also Part I, Section 11).
Formulations should be labelled adequately in accordance with national guidelines.
To reduce further the risk of abuse and to promote the product in regions where even
external alcohol use is problematic because of cultural or religious reasons (see Part I,
Section 14.4), the product name should avoid the term “alcohol” and should be referred
to as a handrub with antimicrobial properties. Both recommended formulations should be
produced in liquid form. Addition of gelling agents may increase production costs and, in
some cases, reduce antimicrobial efficacy140,251.
While sterile distilled water is the preferable component for production of the formulations, cooled, boiled water may also be used.
Glycerol is added to the formulation as a humectant to increase the acceptability of
the product. Other humectants or emollients may be used as long as they are non-toxic,
cheap, widely available, do not cause allergies, and miscible (mixable) in water and alcohol.
Glycerol was chosen because of its historical safety record. The possibility of a lower percentage of glycerol should be investigated to reduce further the risk of stickiness.
The WHO handrub formulations can be used for hygienic hand antisepsis and for surgical
hand preparation. According to EN standards, the efficacy of the formulations is equivalent
to the reference substance for hygienic hand antisepsis, whereas for surgical hand preparation, it is slightly lower. Further results according to both the EN and ASTM standards will
be available in the near future. Substances such as chlorhexidine could be added to achieve
a sustained effect (see Part I, Sections 9.4 and 9.13 for advantages), but this would complicate production and increase costs. For hygienic hand antisepsis, a sustained effect is not
required.
Within the implementation strategy, the use of the WHO formulations at country
level should undergo a pilot phase in a limited number of sites to evaluate feasibility and
acceptability.
10.1.3 Production facilities and cost issues
Manufacture of the WHO handrub formulation should be possible in production units
such as central pharmacies or dispensaries. According to local policies, governments should
make every effort to encourage local production, support the quality assessment process
and keep production costs as low as possible. Since undiluted ethanol is highly flammable
and may ignite at temperatures as low as 10°C, production facilities should directly dilute
it to the above-mentioned concentration. The flash points of ethanol 80% (v/v) and isopropyl alcohol 75% (v/v) are 24°C and 18°C, respectively351, and special attention should be
given to proper storage in tropical climates (see also Part I, Section 9.14.1). National safety
guidelines and local legal requirements have to be considered in the storage of ingredients
and the final product. The WHO handrub formulations should not be produced in quantities above 50 litres locally or in central pharmacies lacking specialised air conditioning and
ventilation. There should be no smoking or naked flames in production and storage areas.
The costs of the WHO handrub formulation may vary according to country, resources
and labour costs; studies to evaluate costs and resource use are necessary. As an example,
in 2005 the costs of an alcohol-based hand rinse developed by a Swiss hospital pharmacy
were (Euros) € 0.57 for a 100 ml pocket bottle, € 1.74 for a 500 ml bottle, and € 3.01 for a
1000 ml bottle. The solution contains chlorhexidine gluconate (0.5%) and isopropyl alcohol
(68.5 g). In Brazil, the prices of a commercially-available alcohol-based formulation based
on ethanol (70% m/m) and glycerine (2%) are US$ 0.45 for a 100 ml disposable bottle and
US$ 3 for a 1000 ml bottle. Nevertheless, the prices of some other commercially-available
products may be much higher.
10.1.4 Safety standards
The recommended handrub formulations have been tested for efficacy according to international norms (see also Part I, Section 8) in WHO-designated independent laboratories.
With regard to skin reactions, handrubbing with alcohol-based solutions is better tolerated
than handwashing with soap and water (see also Part I, Section 11). Any additive should be
as non-toxic as possible in case of accidental or intentional ingestion.
10.1.5 Distribution
To avoid contamination with spore-forming organisms265, disposable bottles should preferably be used although reusable sterilizable bottles may reduce production costs and waste
management. To prevent evaporation, containers should have a maximum capacity of 500
ml on wards, and 1 litre in operating theatres, and possibly fit into a wall dispenser. Leakagefree pocket bottles with a capacity of no more than 100 ml should also be available and
distributed individually to HCWs, but it should be emphasized that the use of these products
should be confined to health care only. The production or re-filling unit should follow norms
on how to clean and disinfect the bottles (e.g., autoclaving, boiling, or chemical disinfection with chlorine). Autoclaving is considered the most suitable procedure. Reusable bottles
should never be refilled until they have been completely emptied and then cleansed and
disinfected.
Cleansing and disinfection process for reusable handrub bottles: empty bottles should be
brought to a central point to be reprocessed using standard operational protocols. Bottles
should be thoroughly washed with detergent and tap water to eliminate any residual liquid.
If heat-resistant, bottles should be thermally disinfected by boiling in water. Whenever possible, thermal disinfection should be chosen in preference to chemical disinfection, since
chemical disinfection not only might increase costs but also needs an extra step to flush out
the remains of the disinfectant. Chemical disinfection should include soaking the bottles in
a solution containing 1000 ppm of chlorine for a minimum of 15 minutes and then rinsing
with sterile/cooled boiled water365. After thermal or chemical disinfection, bottles should be
left to dry completely upside-down in a bottle rack. Dry bottles should be closed with a lid
and stored, protected from dust, until use.
<The WHO Guidelines on Hand Hygiene in Healthcare >
