By Dr. Ken Roy
Posted on 2020-09-02
Personal Protective Equipment (PPE) act as shields or barriers designed to protect teachers and their students in science/STEM labs from exposure to biological, chemical, and/or physical hazards. These include items such as safety goggles or glasses, gloves, aprons, face masks, face shields, and footwear. Masks may help prevent people who have COVID-19 from spreading the virus to others; see Considerations for Wearing Masks (dated 7/31/20). One should not expect the same protection from the coronavirus by using PPE without a face mask. A face mask should never be used in place of any regularly used or required PPE in the laboratory. Given the COVID-19 virus pandemic, cleaning and sanitizing/disinfecting the laboratory and contents is more important than ever!
First of all, teachers should only use sanitizers/disinfectants approved by their school district. If the school board did not approve the purchasing of an item used in the classroom, liability for any incident can be directed solely on the teacher. Though hand sanitizers are meant to clean and disinfect, some are made with toxic chemicals, which will be covered later in this section.
Anyone, staff or student, who is expected to clean must be trained how to clean the surfaces, materials, and equipment that they are responsible for. A log should be kept of the training, and the results of their post-training assessment must be kept on file. The district has a responsibility to develop specific sanitizers/disinfectants use procedures for school personnel. The administration also needs to provide employee training in the use of and the proper protocols to follow when using sanitizers/disinfectants.
Be aware that washing hands with soap and water is preferred over Hand Sanitizers; see Operating schools During COVID-19: CDC's Considerations (dated 7/31/20). This goes along with the “Clean First/Disinfect Second (if needed)” protocol from my previous Safety Blog post. Also remember that social distancing procedures need to be followed when sanitizing/disinfecting laboratories. Appropriate PPE, including, but not limited to safety goggles and appropriate face masks, must also be worn during this cleaning process. In addition to training staff how to clean and disinfect surfaces, they must be trained on how to properly use the PPE.
The CDC and the EPA have a list of disinfectants that can be used against COVID-19 (dated 8/1/20). Make sure that your staff follows all instructions while using the disinfectants. In addition to proper PPE, make sure that they are working in a well-ventilated area. Also make sure Safety Data Sheets (SDSs) are acquired and reviewed prior to application of the sanitizer/disinfectant. Some can be dangerous if instruction/precautions are not followed, such as those containing concentrated alcohol.
Do not use ethanol, isopropanol, or other flammable solutions near active flames, electrical outlets, or hot surfaces. There is risk of fire and explosion! Others, like bleach, can be extremely irritating and corrosive to the user and to the surfaces being cleaned. Before using a disinfectant, make sure that the surfaces are first cleaned with soap and water.
One final piece of advice is this: A disinfection log should be used for each item sanitized/disinfected. Information should include date and time of application, lab, location, and initials of the individual doing the cleaning. Cleaning logs are just as important as the safety inspection logs used for your safety showers and eyewash stations. These logs can be reviewed during Right to Know, OSHA, and Fire Marshal inspections, to name a few, as well as used as evidence in court should the school district or employee be sued. If it was not written, it was not done.
The CDC notes that before using the chemical cleaner, always read and follow the directions on the label to ensure safer and effective use. They also noted the following safety protocols should be addressed (dated 8/1/20):
“Wear skin protection and consider eye protection for potential splash hazards.
Ensure adequate ventilation.
Use no more than the amount recommended on the label.
Use water at room temperature for dilution (unless stated otherwise on the label).
Avoid mixing chemical products.
Label diluted cleaning solutions.
Store and use chemicals out of the reach of children and pets.
You should never eat, drink, breathe, or inject these products into your body or apply directly to your skin, as they can cause serious harm. Do not wipe or bathe pets with these products or any other products that are not approved for animal use.”
The following are several common disinfectants approved for use against COVID-19 virus:
5%-6% sodium hypochlorite bleach concentration of 5%–6%.
Ensure the product is not past its expiration date. Remember that surfaces being cleaned must remain wet for at least one minute, if not longer. Check the instructions. Bleach solutions (1 gallon of water and ⅓ cup of bleach) must be prepared daily in that they can degrade in less than 24 hours. See Cleaning and Disinfecting Your Home (dated 8/1/20).
Additional disinfectants can be found on the Environmental Protection Agency’s list of approved disinfectants for use against SARS-CoV-2 (dated 8/3/20).
Note of caution–Make sure appropriate hand sanitizers that are on the EPA Pesticide Registration list are used. Do not use hand sanitizer by Eskbiochem! This hand sanitizer is made in Mexico with Methanol, a.k.a. Wood Alcohol. Substantial methanol exposure can result in nausea, vomiting, headache, blurred vision, permanent blindness, seizures, coma, permanent damage to the nervous system, or death.
The FDA has an updated list of those hand sanitizers that have been recalled due to their methanol content (dated 8/1/20). In some cases, the labels of these hand sanitizers claimed that ethanol was used in the manufacturing of the hand sanitizer. It only takes 30 ml, a little more than one ounce, of methanol to cause toxic effects on the human body (dated 8/1/20). Also remember that one should wash one's hands frequently and only use hand sanitizer when soap and water are not available.
Examples of required personal protective equipment (PPE) include the following:
Use cloth masks or surgical masks.
Face shields could be worn, but must be worn over safety goggles and masks.
Gloves–nitrile gloves are recommended with cleaning and disinfecting solutions.
Lab coat or disposable gown
Eye protection–indirectly vented chemical splash goggles meeting ANSI/ISEA Z87.1 D3 standard
The safer approach for sanitizing eye PPE right now until we have definitive results is a two-step protocol.
1. Wash goggles and/or glasses with antibacterial soap and warm water.
2. After washing and drying, place them in the goggle sanitizer with UV-C bulbs and run the sanitizer for the amount of time recommended by the sanitizer manufacturer.
Also remember that the sanitizer only "cleans" biologicals on the PPE, not chemicals or physicals. In general, the two-step protocol covers all three potential hazards. If in doubt, eye protection and face shields should be cleaned according to the manufacturer’s recommendations.
Examples of work surfaces and equipment include counters/tables, doors, lab benches, switches, and draw and cabinet pulls, as well as other hard or non-porous surfaces, including composite materials, glass, metal, or plastic.
As with working with all lab chemicals, detergent and/or disinfectant solutions need to be prepared in a clean, dry container. Use the recommended PPE noted above.
Follow manufacturer’s recommendations before cleaning and disinfecting laboratory equipment or instruments. All lab surfaces need to be cleaned and disinfected a minimum of once or twice daily. Surfaces involving dust, smudges, and debris should have regular housekeeping protocols used with water and detergents, then apply disinfectants. Disposable wipes may be placed into the regular trash.
Use disinfectant wipes–not spray bottles–when cleaning surfaces. Spraying surfaces may cause aerosols. If wipes are not available, apply 70% isopropanol to a cloth while avoiding saturation or dripping. Make sure that the room is well ventilated.
Equipment shared by multiple people or lab groups must be cleaned and disinfected before and after each person uses them. Do not allow equipment to be shared that has not been cleaned. Highly-touched surfaces should be cleaned several times a day. Examples of these types of surfaces include countertops, desks, doorknobs, handles, keyboards, light switches, phones, sinks, and tables.
After removing hand PPE, wash hands and forearms thoroughly for at least 20 seconds with soap and warm water.
Always wear the recommended PPE listed above.
Avoid spraying disinfectants directly onto surfaces and potentially getting liquid into equipment openings.
Consider the use of 70% ethanol or 70% to 80% isopropyl alcohol on a soft cloth or pre-moistened wipes. Avoid using harsher disinfectants, like bleach.
For delicate surfaces, such as computers, electronics, instruments, keyboards, microscopes, screens, and tablets, consider the use of wipeable covers when feasible.
Gently wipe the surface until it is visibly wet. Allow it to evaporate.
Make sure to power off all devices. Unplug all external cables, cords, devices, and power sources.
Computers, equipment, and keyboards that are shared should be disinfected after every user. This could be done simply by unplugging the keyboard from the computer if that is the focus of the cleaning.
Wash hands and forearms thoroughly for at least 20 seconds with soap and warm water after removing PPE.
Many important protocols must be followed if schools have a chance of running in a safer manner. Make sure that you spread the word and get as many people as possible on the same page. The protocols include the following:
● Clean with soap and water first, then disinfect (if needed).
● Always clean in a well-ventilated area.
● Washing hands with soap and water is preferred over hand-sanitizing.
● Anyone who is expected to clean must be trained on how to clean and sanitize.
● Everyone needs to be trained on how to effectively wear PPE.
● Make sure all cleaners have been vetted by the EPA. This information can be found on the label.
It is important to label all workplace containers with at least the chemical name and appropriate hazard warnings. Follow labeling protocols stated in the school’s Chemical Hygiene Plan. For cleaning of more sensitive equipment, contact the manufacturers for advice on cleaning products and disinfectants to use on items such as centrifuges, microscopes, and other sensitive lab equipment. Some cleaners can be corrosive and damage equipment.
Submit questions regarding safety to Ken Roy at email@example.com. Follow Ken Roy on Twitter: @drroysafersci
Safety Blog Acknowledgement: NSTA Chief Safety Blogger Dr. Ken Roy wishes to sincerely thank nationally recognized District Supervisor of Science Kevin S. Doyle, Ed. D., of Morris Hills Regional High School District, Rockaway, New Jersey (firstname.lastname@example.org) for his professional review of this commentary.
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