Lesson Notes By Weeks and Term v3 - Senior Secondary 2
Sterilization
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Sterilization
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Subject: Cosmetology
Class: Senior Secondary 2
Term: 2nd Term
Week: 5
Theme: General Safety Precaution And Hygiene
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Definesterilization List method of sterilization Mention typesof sterilization List materialfor sterilization carry out sterilization of items.
Ultraviolet-C (UV-C) light destroys the DNA of microorganisms, preventing them from reproducing. While often advertised for sterilization in salons, UV sterilizers commonly found in salons are primarily effective for surface disinfection and storage, not true sterilization of critical instruments, especially if items are not thoroughly cleaned and exposed directly for sufficient time.
Equipment: UV sterilizer cabinet.
Advantages: Chemical-free. Relatively safe for users when operated correctly.
Disadvantages: Limited penetration (only surface sterilization). Items must be clean and dry. Long exposure times often required for significant microbial reduction, and still generally insufficient for true sterilization (killing spores). UV light can degrade plastics over time. The teacher should emphasize that UV is mostly for sanitized storage of instruments, not primary sterilization.
B. Chemical Methods (Liquid Sterilants): These methods involve the use of strong chemical solutions to kill microorganisms. They are particularly useful for heat-sensitive instruments.
1. High-Level Disinfectants/Chemical Sterilants: Mechanism: These chemicals act by denaturing proteins, disrupting cell membranes, and damaging nucleic acids of microorganisms. When used for extended contact times, they can achieve sterilization. Examples of commonly available chemical sterilants in Nigeria: Glutaraldehyde (e.g., Cidex): A potent sterilant when used for prolonged immersion (e.g., 6-10 hours). It is often used for heat-sensitive items.
Hydrogen Peroxide: High concentrations (e.g., 7.5% or more) can be used as a sterilant.
Peracetic Acid: Often used in automated systems, less common in small Nigerian salons.
Bleach (Sodium Hypochlorite): While a strong disinfectant, it is generally considered a high-level disinfectant, not a true sterilant for all purposes unless used at very high concentrations and for extended times, which can be corrosive. Best for surface disinfection.
Equipment: Non-corrosive immersion trays or containers with lids.
Advantages: Suitable for heat-sensitive and moisture-sensitive instruments (e.g., certain plastics, delicate tools). No need for specialized heating equipment.
Disadvantages: Requires long immersion times for sterilization (often hours). Chemicals can be toxic, irritating to skin, eyes, and respiratory system; requires good ventilation and PPE. Require thorough rinsing with sterile water after immersion to remove chemical residue, which adds a step and risk of recontamination if water is not sterile. Expiration dates and proper disposal are critical. Corrosive to some metals if not formulated with rust inhibitors. Cannot penetrate organic material, so instruments must be thoroughly pre-cleaned.
Example Application: Sterilizing plastic combs, brushes, facial spatulas, non-metallic tools, foot files (non-abrasive parts) that cannot withstand heat. 2.
3. Types of Sterilization This refers to the broad categories of sterilization based on the agent or approach. Based on the methods discussed, the primary types encountered in cosmetology are:
1. Physical Sterilization: Utilizes physical agents. Heat Sterilization (Dry Heat, Moist Heat) Radiation Sterilization (UV-C - primarily for surface disinfection/storage in salons)
2. Chemical Sterilization: Utilizes chemical agents. Liquid Chemical Sterilization (e.g., Glutaraldehyde, Hydrogen Peroxide solutions). 2.
4. Materials for Sterilization A wide range of items used in cosmetology require sterilization, especially those that come into contact with blood, bodily fluids, or non-intact skin.
1. Metal Instruments: Cuticle nippers/cutters Nail files (reusable metal ones) Pushers (cuticle pushers, nail cleaners) Scissors (hair cutting, cuticle scissors) Tweezers Comedone extractors (for facials) Razor blades (if reusable, though disposable are preferred) Dermaplaning tools (if reusable)
2. Non-Metallic Items (Heat-sensitive): Combs Brushes (hair brushes, facial brushes with plastic handles) Plastic bowls (for mixing, soaking) Spatulas (plastic, silicone) Some electric handpieces or attachments (check manufacturer's instructions) Foot files (non-abrasive parts)
3. Porous Materials (if reusable): Towels (face towels, hand towels) Cotton pads (reusable fabric type) Gauze 2.
5. Carrying out Sterilization of Items (Step-by-step procedure) The following is a generalized procedure applicable to both heat and chemical sterilization, with specific points highlighted for each. This general protocol ensures effective sterilization.
General Steps for Sterilization: Step 1: Pre-Cleaning (Crucial)
Purpose: To remove all visible debris, dirt, blood, tissue, and other organic matter from the instruments. Organic matter can protect microorganisms from the sterilizing agent, rendering the sterilization ineffective.
Procedure: * Immediately after use, 20-30 minutes). Teacher
Note: Emphasize strict adherence to manufacturer's instructions for concentration, immersion time, and reuse period of the solution. After immersion, use sterile forceps or gloves to remove instruments.
Step 6: Post-Sterilization Rinsing (for Chemical Sterilization ONLY)
Purpose: To remove chemical residues from instruments before use, as they can be irritating or toxic.
Procedure: After removing instruments from the chemical solution, rinse them thoroughly with sterile water (e.g., distilled water that has been autoclaved or boiled and cooled in a sterile container). This step is critical to prevent re-contamination.
Step 7: Storage Purpose: To maintain the sterility of the instruments until they are needed.
Procedure: For heat-sterilized, packaged instruments: Store them in a clean, dry, covered, and designated sterile storage area. For chemically sterilized instruments that have been rinsed with sterile water: They should ideally be used immediately or stored in a sterile, covered container for a very short period (e.g., a few hours) as their sterility is difficult to maintain outside a sterile package. Teacher
Note: Emphasize that once a sterile package is opened or compromised, the item is no longer considered sterile. Safety Precautions for all Sterilization Procedures: Always wear appropriate Personal Protective Equipment (PPE), including gloves, eye protection, and aprons. Ensure adequate ventilation when using chemical sterilants. Handle hot instruments with heat-resistant gloves. Follow manufacturer's instructions for all equipment and chemical solutions. Dispose of chemicals and contaminated materials according to local environmental regulations. reusable): Towels (face towels, hand towels) Cotton pads (reusable fabric type) Gauze 2.
5. Carrying out Sterilization of Items (Step-by-step procedure) The following is a generalized procedure applicable to both heat and chemical sterilization, with specific points highlighted for each. This general protocol ensures effective sterilization.
General Steps for Sterilization: Step 1: Pre-Cleaning (Crucial)
Purpose: To remove all visible debris, dirt, blood, tissue, and other organic matter from the instruments. Organic matter can protect microorganisms from the sterilizing agent, rendering the sterilization ineffective.
Procedure: Immediately after use, rinse instruments under running water. Soak instruments in an enzymatic cleaner solution or detergent solution to loosen stubborn debris. Using a scrub brush or ultrasonic cleaner, thoroughly scrub all surfaces, crevices, and hinges of the instruments. Ensure all visible contaminants are removed. Teacher
Note: Emphasize the use of gloves and eye protection during this step.
Step 2: Rinsing Purpose: To remove all detergent or cleaning solution residues. Residues can interfere with the sterilizing agent or cause instrument discoloration/damage.
Procedure: Rinse instruments thoroughly under clean running water.
Step 3: Drying Purpose: To prevent corrosion and rust of metal instruments (especially for dry heat) and to prevent dilution of chemical sterilants.
Procedure: Dry instruments completely using a clean, lint-free cloth or by air drying.
Step 4: Packaging (for Heat Sterilization)
Purpose: To maintain sterility of the items after the sterilization cycle until they are ready for use.
Procedure: For dry heat or moist heat (autoclave), place instruments in sterilization pouches, wraps, or appropriate containers (e.g., metal boxes with perforations for steam penetration) that are permeable to the sterilizing agent but impermeable to microorganisms. Ensure items are not overcrowded to allow proper circulation of the sterilizing agent. Teacher
Note: This step is generally not applicable for immediate use with chemical sterilization unless items are stored after rinsing with sterile water.
Step 5: Sterilization Process
A. For Dry Heat Sterilization (e.g., Hot Air Oven): Preheat the dry heat sterilizer to the recommended temperature (e.g., 160°C). Carefully place the packaged and dried instruments inside, ensuring there is space for air circulation. Close the sterilizer door and set the timer for the recommended duration (e.g., 2 hours at 160°C). Allow the full cycle to complete. Once the cycle is complete, turn off the sterilizer and allow the instruments to cool down inside the sterilizer before opening the door. This prevents warping and recontamination from ambient air.
Safety: Use heat-resistant gloves when handling.
B. For Moist Heat Sterilization (Autoclave or Pressure Cooker): Load the packaged items into the autoclave/pressure cooker, ensuring proper arrangement for steam penetration. Add the recommended amount of distilled water to the chamber. Seal the chamber according to manufacturer's instructions. Set the temperature and pressure (e.g., 121°C at 15 psi) and time (e.g., 20 minutes for packaged items). Allow the cycle to complete, including the drying phase (if applicable). Carefully open the chamber once pressure has fully dropped, using heat-resistant gloves.
C. For Chemical Sterilization (e.g., Glutaraldehyde): Pour the chemical sterilant into a non-corrosive tray or container with a lid, ensuring sufficient volume to fully immerse all instruments. Carefully immerse the thoroughly pre-cleaned and dried instruments into the solution. Ensure no air bubbles are trapped. Cover the container to minimize fumes and prevent evaporation. Set a timer for the recommended immersion time for sterilization (e.g., 6-10 hours, depending on the product and desired level). For high-level disinfection, times are shorter (e.g., 20-30 minutes). Teacher
Note: Emphasize strict adherence to manufacturer's instructions for concentration, immersion time, and reuse period of the solution. After immersion, use sterile forceps or gloves to remove instruments.
Step 6: Post-Sterilization Rinsing (for Chemical Sterilization ONLY)
Purpose: To remove chemical residues from instruments before use, as they can be irritating or toxic.
Procedure:** After removing instruments from the chemical solution, rinse them thoroughly with sterile water (e.g., distilled water that has been autoclaved or boiled and cooled in a sterile container). This step is critical to This section provides in-depth explanations of the core concepts related to sterilization for the teacher's comprehensive understanding. 2.
1. Definition of Sterilization Sterilization is the complete destruction or removal of all forms of microbial life, including bacteria, viruses, fungi, and particularly bacterial spores, from an object or surface. It is the highest level of decontamination and is crucial for items that will penetrate skin or mucous membranes, or contact non-intact skin.
Differentiation from other terms: Sanitation: The process of significantly reducing the number of microorganisms on a surface to a safe level, typically using soap and water or detergents. It cleans rather than kills all microbes.
Example: Washing salon floor, wiping down reception desk.
Disinfection: The process of destroying most pathogenic (disease-causing) microorganisms on inanimate objects or surfaces, but it does not necessarily kill bacterial spores. Disinfectants are typically stronger than sanitizers.
Example: Wiping down manicure tables with an antiseptic solution.
Antisepsis: The process of reducing or inhibiting the growth of microorganisms on living tissue (e.g., skin) to prevent infection. Antiseptics are generally milder than disinfectants.
Example: Applying spirit to a client's skin before a treatment. 2.
2. Methods of Sterilization There are various methods employed for sterilization, primarily categorized into physical and chemical methods.
A. Physical Methods: These methods use physical agents like heat or radiation to achieve sterilization.
1. Heat Sterilization: This is the most common and reliable method. a.
Dry Heat Sterilization: Mechanism: Achieves sterilization by oxidation (burning up) of microbial cells. It is suitable for items that can withstand high temperatures without damage and that cannot be easily penetrated by moist heat (e.g., powders, oils, sharp instruments).
Equipment: Dry heat sterilizer (e.g., hot air oven). These are commonly found in Nigerian salons, though sometimes incorrectly used as simple dryers.
Typical Temperatures and Times: Requires higher temperatures and longer exposure times compared to moist heat. 160°C (320°F) for 2 hours 170°C (340°F) for 1 hour Advantages: Non-corrosive for metal instruments and sharp objects (maintains sharpness). Suitable for items sensitive to moisture (oils, petroleum jelly, powders). Relatively simple to operate.
Disadvantages: Longer sterilization cycles. High temperatures can damage heat-sensitive materials (e.g., plastics, rubber). Poor penetration, so items must be spread out evenly.
Example Application: Sterilizing metal instruments like cuticle nippers, nail files (reusable metal ones), scissors, tweezers used in manicure and pedicure services. b.
Moist Heat Sterilization (Autoclaving): Mechanism: Achieves sterilization by denaturing and coagulating (solidifying) proteins within microbial cells, including spores. It uses steam under pressure to reach higher temperatures than boiling water.
Equipment: Autoclave (a pressure chamber that uses steam). Domestic pressure cookers can serve as a rudimentary autoclave if specific conditions (pressure and temperature maintenance) are met for smaller items, though not recommended for professional salon settings due to lack of validation.
Typical Temperatures and Times: 121°C (250°F) at 15 psi (pounds per square inch) for 15-30 minutes. 132°C (270°F) at 30 psi for 4-10 minutes.
Advantages: Faster and more effective than dry heat for most items. Steam provides excellent penetration. Suitable for heat-resistant and moisture-resistant materials.
Disadvantages: Can corrode or dull sharp metal instruments if not properly dried or made of susceptible materials. Not suitable for heat-sensitive or moisture-sensitive materials (oils, powders). Requires a more specialized and potentially expensive equipment (autoclave).
Example Application: Sterilizing porous materials like towels, cotton pads, gauze, certain plastic instruments that are heat- and moisture-resistant, glass items, and some metal instruments.
2. Radiation Sterilization (UV-C Light): Mechanism: Ultraviolet-C (UV-C) light destroys the DNA of microorganisms, preventing them from reproducing. While often advertised for sterilization in salons, UV sterilizers commonly found in salons are primarily effective for surface disinfection and storage, not true sterilization of critical instruments, especially if items are not thoroughly cleaned and exposed directly for sufficient time.
Equipment: UV sterilizer cabinet.
Advantages: Chemical-free. Relatively safe for users when operated correctly.
Disadvantages: Limited penetration (only surface sterilization). Items must be clean and dry. * Long exposure times often required for significant
Public Health and Client Safety in Nigerian Salons: The knowledge of sterilization is directly applicable to maintaining hygienic standards in every hair salon, barbershop, and beauty spa across Nigeria. By consistently sterilizing tools like clippers, scissors, and manicure implements, cosmetologists prevent the transmission of common infections such as ringworm, boils, fungal infections (e.g., athlete's foot from pedicure bowls), and more serious blood-borne pathogens like Hepatitis B and C. This builds client trust and protects the wider community's health.
Entrepreneurship and Professionalism: For students aspiring to open their own beauty businesses in Nigeria, mastering sterilization techniques is paramount. It ensures compliance with potential local government health regulations (e.g., Lagos State Environmental Protection Agency guidelines), helps in acquiring and retaining clients who prioritize safety, and ultimately contributes to the reputation and success of their enterprise. A salon known for its strict hygiene practices will attract and retain more discerning clients.
Infection Control in General Practice: Beyond cosmetology, the principles of sterilization are fundamental in healthcare settings, hospitals, and even local maternity homes or traditional birth attendant centers. Understanding these principles provides a foundational knowledge of infection control that can be applied to various professional fields or personal hygiene practices within Nigerian homes. For instance, the same principles of sterilizing medical instruments apply to sterilizing tools in a traditional piercing parlor, highlighting the broad impact of this knowledge.