Knowing how to effectively clean your home, car or work space and wash your hands can protect you during cold and flu season, in the midst of a global pandemic or any other time of year.
Washing Your Hands
Do you effectively wash your hands? How long do you wash your hands? What temperature water do you use? Washing your hands effectively is the best prevention you have against preventing illness or from carrying hazardous materials out of your work area. Follow these tips for hand washing that actually protects you and your loved ones.
Or watch our YouTube video on proper hand washing steps.
Print our hand washing posters to place near hand washing sinks in your home or office.
Want EHS to come do a hand washing exercise with your department, office, section or research group? Ask us! We provide Glow Germ (fluorescent lotion), black lights and Glo Germ view boxes to demonstrate where hand washing techniques can be approved.
Some people may also use gloves during their work procedures, cleaning around the house, or while visiting public places. Follow these tips to use your gloves properly.
- Do not touch your personal objects that you will touch with ungloved hands such as your cell phone or purse.
- Do not touch your face, eyes, mouth, glasses, skin, etc. This helps prevent contamination on your person.
- Just because your gloves are not visibly dirty does not mean they are not contaminated.
- Limit the number of items you touch.
- If you are wearing gloves for an extended period of time, like at work, change them frequently. Gloves can become compromised during use and then you have lost your protective barrier.
- Do not wear the same pair of gloves for multiple tasks (e.g., visiting multiple stores). If you choose to wear gloves, don a fresh pair for each location.
- Remove gloves promptly after use and discard into a trash receptacle.
So how do you remove gloves without contaminating your skin with what you are trying to protect yourself from in the first place? Watch our YouTube video for a step-by-step how to!
You can also print our glove removal posters to hang in your work areas!
Cleaning Work Surfaces
Whether you are cleaning lab benches or common kitchen or office areas, using the proper disinfectant is a vital part of keeping your space clean and free of germs or other contamination. There are many factors that impact decontamination.
- Microbial load (number and variety of organisms present)
- Organism life cycle (does the organism form spores?)
- Innate resistance of the organisms
- Presence of biofilms
Physical and Chemical Factors
- Temperature and pH can increase/decrease efficacy of a chemical disinfectant
- Presence of organic and inorganic materials.
- Organic matter can create physical barriers reducing contact and bind antimicrobial agents decreasing overall concentration of the effective agent in a solution.
- Inorganic matter can create a physical barrier in the formation of salt crystals.
- Disinfectant concentration
- Duration of exposure or "contact time"
Before we look at the different types of disinfectants, let's talk about some definitions.
Cleaning – the removal of foreign material, such as soil or other organic material, from objects or surfaces through water with detergents/enzymes. Cleaning is necessary for high-level disinfection and sterilization as inorganic and organic matter interferes with the efficacy of these processes. Additionally, failure to remove material may result in buildup and further difficulties with disinfection and sterilization.
Decontamination – the removal or neutralization of a hazardous/unwanted agent or the destruction/removal
of microorganisms to some acceptable level which may not
necessarily be zero. Sanitation, disinfection, antisepsis and sterilization, are all forms of decontamination.
Disinfection – the use of (liquid/chemical) antimicrobial agents on inanimate objects to destroy
or irreversibly inactivate all infectious fungi and bacteria but not their spores.
Disinfectants can be "general" or "hospital' grade. Chemical disinfectants are used
to render a contaminated material safe for further handling, whether it is a material
to be disposed of as waste or a laboratory bench on
which a spill has occurred. It is important to choose a disinfectant that has been proven effective against the material(s) or agent(s) being used and at the appropriate concentration.
Sanitation – the reduction of microbial load on an inanimate object/surface to an acceptable level.
Sterilization – implies destroying all viable organisms and their spores on the surface of an article or in a fluid; measured as the probability of a single viable microorganism surviving the process.
Contact time – the duration of exposure required for a disinfectant to effectively destroy or irreversibly inactivate a biological agent.
-cidal – kills or inactivates an agent or material. (e.g., bactericidal, fungicidal, sporicidal, tuberculocidal, virucidal, etc.)
-static – repression of growth or multiplication of an agent in its presence. (e.g., bacteriostatic, fungistatic, etc.)
Basic Steps to Proper Disinfection
- Chemical disinfectants are not intended for use on skin. Do not apply surface disinfectants, such as Lysol, to ANIMATE objects (i.e., yourself or clothing); you need an antiseptic (skin disinfectant) for this purpose.
- Chemical disinfectants are not intended to be mixed together; more (chemicals or concentration) is not better - most importantly avoid mixing anything with bleach.
- Properly use, store and dispose of chemical disinfectants per the manufacture's instructions on the label.
- Clean away debris and organic matter first.
- Prepare fresh disinfectant according to the manufacturer guidelines for concentration and frequency of preparation.
- Evenly apply the disinfect to the surface to be decontaminated and allow the surface to remain wet for the duration of the required contact time. Reapply if needed.
- Wipe to dry if needed AFTER contact time.
Choosing a Disinfectant
There are many different types of disinfectants available. Choosing the correct one can be overwhelming. Use the information below to assist you in your choice! Always read the container labels to determine the appropriate function, use the disinfectant according to manufacturer instructions and leave it in contact with the work surface for the appropriate contact time.
- Recommended dilution is 75-5,000 mg/L (ppm), or approximately 0.5% concentration
- Effective against vegetative bacteria, fungi, and viruses
- Some are antiseptics (e.g., betaydyne, scrubodyne)
- Some are surface disinfectants (e.g., Wescodyne™ Steris Corporation)
- Effectiveness reduced by organic matter (but not as much as with hypochlorites)
- Stable in storage if kept cool and tightly covered. Built-in color indicator; if solution is brown to dark yellow, it is still active.
- Generally non-staining
- Active in hard water
- Relatively harmless to humans
- Not as corrosive as chlorine products; leaves a film of residue which allows for residual antimicrobial activity
- Can stain and discolor equipment in some conditions
- Can be corrosive to silver, copper, and aluminum but relatively harmless to stainless steel
- Can foam
- Cannot be used above 110°F (iodine vaporizes) and is not as effective in low temperature environments (cold rooms, refrigerators, etc.)
- Cannot be used in conjunction with other products
Sodium hypochlorite (bleach)
- User dilution is 1:5 to 1:100 in water; 20% to 1% dilution.
- Strips to test ppm can be purchased.
- Contact time varies with agent to be neutralized and concentration of solution.
- Only Clorox brand bleach has been approved by the EPA as a disinfectant; however, any brand of sodium hypochlorite will meet the requirements of Texas law.
- Effective against vegetative bacteria, fungi, most viruses at 1:100 dilution
- Available free chlorine is maximized when the solution is pH 5-7
- Recipe for large quantity ~1% solution with 800 ppm available chlorine:
- 1:64 dilution of Clorox in water (2oz in 1 gallon of water)
- 2oz of 5% distilled white vinegar (cooking vinegar)
- Make daily as the solution quickly inactivates
- Store prepared solutions in brown plastic bottles to protect from light
- Broad spectrum effectiveness
- Readily available and inexpensive
- High concentrations can kill spores and remove biofilms
- Fast acting
- Very corrosive, especially to stainless steel
- Must be prepared daily for effective available ppm chlorine concentration
- Rapidly inactivated by organic matter, light, and some metals
- WARNING!! Bleach in combination with other cleaners can produce deadly, toxic compounds
- Bleach + 4% phosphoric acid cleaner = chlorine gas
- Bleach + Ammonia containing cleaner = chloramine vapors and potentially hydrazine
Alcohols (ethanol, isopropanol)
- The effective dilution for decontamination is 60-80%; 70% is ideal
- Effective against a broad spectrum of bacteria and many viruses
- Ethanol is preferred to isopropanol given it has a slightly more broad-spectrum kill.
- Ethanol inactivates all lipophilic viruses and many hydrophilic viruses.
- Isopropanol is not active against hydrophilic viruses but virucidal against lipophilic viruses.
- Use the C1* V1 = C2 * V2 formula to calculate the concentration you wish to make
- Fast acting and quick drying
- Leaves no residue
- Relatively inexpensive
- Broad spectrum effectiveness against bacteria and viruses
- Maintains activity in presence of organic matter
- Not effective against bacterial spores, C. difficile and Helicobacter
- Evaporate rapidly not allowing for extended contact time unless an item is immersed
- FLAMMABLE; use only on small surface areas and in well-ventilated areas
- Certain agents require a lengthy contact time (30 minutes or more)
- Attacks acrylic, polypropylene, PVC and polycarbonate plastics and rubber overtime or with prolonged or repeated use
- Can coagulate proteins and attach them to surfaces
- Can compromise latex and vinyl gloves with extended exposure (1 hour)
- Cannot penetrate protein-rich materials (e.g., dried blood/plasma)
Quaternary Ammonium Salts/Amines ("Quats")
- Dilute according to manufacturer instructions
- Spectrum of effectiveness varies with manufacturer; generally effective against Gram positive bacteria, Gram negative bacteria and enveloped viruses
- Quats sold as hospital-grade disinfectants are generally bactericidal, fungicidal and virucidal (Examples include Lysol, BacDown)
- 4th generation QUATs maintain effectiveness in the presence of organic material and hard water
- Can be used to both clean and sanitize
- Readily available, generally inexpensive
- Low-level human toxicity
- Excellent for walls, furniture and floors
- Some not effective against non-enveloped viruses, spores or fungi
- Hard water and organic matter can reduce effectiveness
- Cellulose-containing materials can absorb active ingredients
- Some people are prone to allergies and skin-reactivity
- Dilute according to manufacturer instructions
- Effective against bacteria, fungi and enveloped viruses
- Maintain good activity in the presence of organic material and hard water
- Residue has some residual activity after drying
- Ineffective against non-enveloped viruses, spores and some Gram negative bacteria
- Toxic to infants and the environment
- Prolonged exposure can cause allergies and skin irritation
Hydrogen Peroxide (3-8%)
- Surface sterilant
- Broad-spectrum effectiveness
- Aqueous hydrogen peroxide concentration 3-8% for spray application and >30% for vaporization
- Environmentally safe by-products (H2O, O2)
- Rapid kill action
- No disposal issues, odor or irritation when diluted (3-8%)
- Readily available and inexpensive
- Good compatibility with sensitive equipment, electronics and furnishings
- Little penetration
- Concentrations >7.5% can cause discoloration of metal finishes
- Compatibility concerns with brass, zinc, copper, and nickel/silver plating
- Oxidizing capability is rapidly inactivated by organic material; cellulose cannot be processed
- Nylon items can become brittle
- Vapors have no color and are odorless; inadvertent exposure can cause serious health effects