Disinfection. Pesticide control. Rodent control manual

Author: / Country: Mainland China
Publisher:
Publishing Date: 2004-01-01
Features:
Drinking Water Disinfection: At a dose of 5 mg/L, the concentration after 5 minutes of action achieves disinfection purposes better than liquid chlorine.
Item Immersion Disinfection Dose: For bacterial vegetative cells, use a concentration of 100 mg/L for 30 minutes. For hepatitis viruses, use a concentration of 500 mg/L for 30 minutes. For bacterial spores, use a concentration of 1000 mg/L for 30 minutes.
Note: Chlorine dioxide is unstable after activation and is corrosive.
(2) Chlorine-based Disinfectants: Suitable for disinfecting environments, tableware, tea sets, water, and waste.
Note: Chlorine-based disinfectants are unstable, corrosive, and have bleaching effects. The impact of organic matter on disinfection effectiveness in environmental disinfection is significant, so the action time should be appropriately extended, and the concentration of the disinfectant should be increased.
(3) Povidone-iodine: Suitable for skin and mucosal disinfection. Since povidone-iodine is formed by the complexation of iodine with multiple surfactants, the active disinfectant components can slowly release to achieve disinfection effects and also have a decontaminating function.
(4) Chlorhexidine and Quaternary Ammonium Salts: Suitable for surgical handwashing, skin and mucosal disinfection, and surface disinfection of items; not suitable for use as sterile instrument storage solutions.
Note: These disinfectants should not be mixed with anionic surfactants.
4. Sterilization of Surgical Instruments and Supplies
(1) Heat-resistant surgical instruments should be preferably sterilized using steam sterilization (washing, drying). Non-heat-resistant items can be sterilized using ethylene oxide.
Ethylene oxide sterilization conditions: Ethylene oxide concentration of 800–1200 mg/L, temperature of 55–60°C, relative humidity of 60%–80%, and sterilization time of 6 hours.
Post-sterilization treatment: After sterilization, the adsorbed ethylene oxide must be driven off before use. Due to differences in ethylene oxide absorption rates among different materials, the desorption times vary.
Natural rubber: 35,000 ppm, desorption time of 1–2 weeks;
Synthetic rubber: 20,000 ppm, desorption time of 1–2 weeks;
Cotton: Polyethylene and polypropylene have low absorption rates and can be used as packaging materials.
For hospital ethylene oxide sterilization: Surgical instruments need to be desorbed in a desorption machine for 1–2 hours before use.
(2) Sterilization of Surgical Sutures: Non-absorbable sutures and silk sutures are commonly sterilized using steam sterilization. When using downflow steam sterilization, the temperature is 121°C, and the action time is 20 minutes. The temperature should not be too high during sterilization to avoid affecting the tensile strength of the sutures. Other items can be sterilized using ethylene oxide.
(3) Sterilization of Sharp Surgical Instruments: Sterilization of sharp surgical instruments must ensure both sterilization quality and the preservation of their sharpness. Therefore, sterilization can be achieved using dry heat sterilization with ethylene oxide, glutaraldehyde, or rapid steam sterilization.
① Dry heat sterilization: Under conditions of 160–180°C, the action time is 1–2 hours;
② Ethylene oxide: At a temperature of 54±2°C and relative humidity of 60%–80%, with an ethylene oxide concentration of 600–800 mg/L, the action time is 4 hours;
③ 2% glutaraldehyde, covered and soaked for 7–10 hours to achieve sterilization.
(4) Surgical Dressings: Surgical dressings include polypropylene wound dressings, non-woven fabrics, and oil gauze, which can be separately sterilized using steam sterilization or ethylene oxide. Steam sterilization is the primary method, as it is stable, non-toxic, and widely used. Specific parameters can be determined based on the type of steam sterilization equipment. Ethylene oxide sterilization is most suitable at a temperature of 5±2°C, relative humidity of 60%–80%, with an ethylene oxide concentration of 600–800 mg/L, and an action time of 4 hours. After sterilization, it must be desorbed in a desorption machine for 1 hour.
5. Sterilization of Injection Equipment:
Injection equipment, including syringes and infusion (blood) sets, must be strictly sterilized using the three-step method: disinfection, cleaning and drying, and sterilization. The using department should disinfect on-site after use and then send it to the supply room for cleaning and sterilization. Common sterilization methods include steam sterilization and ethylene oxide sterilization. Steam sterilization at a pressure of 2.1 kg/cm2 and a temperature of 132°C, with a downflow steam sterilization at 121°C for 30 minutes, can achieve sterilization. Ethylene oxide disinfection is mainly suitable for disinfecting heat-sensitive single-use items.
6. Disinfection and Sterilization of Endoscopes
(1) Basic Principles:
① Endoscopes for different body parts should be disinfected or sterilized separately, and biopsy forceps must be sterilized;
② Patients with tuberculosis, hepatitis, AIDS, or carriers of pathogens should use dedicated endoscopes, which must undergo specific disinfection treatment, then cleaned, and disinfected or sterilized. For endoscopes used by general patients, they can be cleaned first, then disinfected or sterilized.
③ Endoscopes immersed in disinfectant solutions should be rinsed with water to remove residual disinfectants, including the inner cavity of the endoscope.
(2) Disinfection or Sterilization Methods:
The primary method is thermal sterilization: steam sterilization at 121°C for 20 minutes. Heat-sensitive endoscopes can be disinfected chemically.
① Ethylene oxide disinfection: Ethylene oxide sterilization dose of 1000 mg/L, action time of 4 hours, or 800 mg/L for 6 hours, or 600 mg/L for 2 hours, at 50–60°C and relative humidity of 70%. A concentration of 800 mg/L of ethylene oxide for 4 hours, or 600 mg/L for 6 hours.
② 2% glutaraldehyde, action time of 20 minutes, for tracheal scopes, gastroscopes, colonoscopes, and laryngoscopes; for tuberculosis and hepatitis, the action time should be 45 minutes. 2% glutaraldehyde for 10 hours is used for cystoscopes, laparoscopes, and arthoscopes for sterilization.
7. Disinfection of General Diagnostic Supplies:
Choose disinfection methods and levels based on the microbial contamination of the disinfection objects. Boiling disinfection is suitable for treatment supplies made of metal, glass, etc. Metal, ceramic, glass, rubber, heat-resistant plastic, and cotton products can be sterilized using steam sterilization. For heat-sensitive diagnostic supplies, such as thermometers and oral scopes, chemical disinfectants can be used for immersion or wiping disinfection. Valuable items can be disinfected using ethylene oxide or formaldehyde gas.
8. Hand Disinfection for Medical Staff:
During various medical activities, medical staff's hands frequently come into contact with patients and related items, making them easy to become disease transmission. Therefore, hand hygiene disinfection must be performed before and after various diagnoses and care. Soap and water washing is a simple and practical method, mechanical action can remove 80% of contaminated microorganisms, and handwashing with disinfectants can only remove 90%–95% of pathogenic microorganisms. Additionally, if hands are contaminated with or suspected to be contaminated with pathogens, they must be disinfected with disinfectants.