In a pandemic, infrastructure collapse or other widespread emergency situations, hospitals could quickly be overloaded and care of an ill or injured person would by necessity be done at home. Quarantine, either self imposed or by government order, is one way of containing epidemics. Proper disposal of infectious waste is also critical to avoid spreading the contagion.
Merely burning the waste is not a good option; not only does burning of materials release pollutants into the air, fire often does not burn hot enough or long enough to completely destroy the waste. So waste needs to be sorted as to its treatment and disposal requirements. First, harmful waste (contaminated) needs to be separated from other wastes.
Uncontaminated waste can then be sorted into discards, recyclables, paper and food scraps. Food scraps are compostable for soil improvement. Paper can be recycled by burning for heat or cooking (make rolled ‘logs’ or ‘bricks’), or shredded to add to the compost pile (if it is printed with non-toxic inks, like newspapers), used as mulch, or recycled. Recycle items can be recycled either through trash collection channels or sold to recyclers, leaving only the ‘discards’ to deal with in landfill or by burial.
Infectious or hazardous medical wastes, however, require special treatment to make them safe to handle before they are disposed of. So obviously reducing the amount of waste is a good idea. Avoid using disposable items if a reusable version is available. Use non-mercury thermometers if available. Use pills instead of injections, non-plastic items when possible, and use the least toxic products to clean and disinfect whenever possible.
Disinfection is NOT the same as sterilizing. Sterilizing kills ALL the kinds of germs on something so it will not transmit infection. Disinfection kills enough germs, but not all, so that the item will not transmit infection. There are several levels of disinfection.
I will be describing ‘high level’ disinfection which kills almost all the germs on something, so they can be safely disposed of (or further treated for re-use). Sorting of hazardous wastes is necessary since different items are disinfected in different ways.
Wastes that need to be disinfected include:
Used sharps (needles, blades, etc); blood and body fluids; things that carry body fluids (bandages, swabs, other wastes); other items contaminated with body fluids, blood or feces; feces with people with infectious diseases (such as cholera); bedding from all persons.
Things that do NOT need disinfecting:
body parts, waste water from disinfection and cleaning, chemicals, food waste, feces from healthy people, and any materials not contaminated with blood or body fluids (cardboard, paper, plastics, glass, metals).
Waste needs careful storage until it can be sorted and treated. Seal waste bins and bags when only 3/4 full for safety (they are less likely to spill or break when picked up). If there is leakage, double-bag. Keep in a closed room secure from scavenging and animals. Health care waste can only be stored safely for specific amounts of time before it begins to stink and risk spreading infection through decomposition:
Moderate climate – 3 days in winter, 2 days in summer
Warm climate – 2 days in cool season, 1 day during hot season.
After these times, waste must be treated or transported away. Wear protective gear (safety glasses, face masks, thick rubber gloves, an apron, clothing that covers the entire body with long sleeves and trousers, and rubber boots). Use a cart or wagon with no sharp edges to tear bags open. Never put sharps in bags with other waste – they should be in a hard box. Wash hands after handling wastes, and do not let it touch your body. After use, wash your gloves, aprons, glasses and masks. (If you run out of gear, improvise by making plastic garbage bags to make protective aprons, pants, masks and hats. It is better to have some protection than none at all!)
The 2 most common methods of waste disinfection in home health care practice are disinfection with chemicals (bleach, hydrogen peroxide, or other chemicals) and disinfection with heat (boiling, steaming, pressure cooking, or microwaving).
Disinfecting with chemicals
This is a common technique used with walls, floors, furniture and other hard surfaces. Some common chemicals used are chlorine bleach, isopropyl alcohol, hydrogen peroxide and common pre-made cleaning and disinfecting products. However, some commercial disinfectants contain chemicals which can cause cancer with regular exposure (glutaraldhyde and formaldehyde). No matter which ones you use, treat them with respect. Wear safety clothing, a mask and eye protection. Keep them in their proper containers and do not mix them. Make sure they do not leak.
Wastes best treated with chemicals are body fluids, blood and feces.
Separate these wastes into special containers, then disinfect with bleach before burying. Bedpans and bedding should also be disinfected with bleach, then washed with hot water and soap, and the use bleach diluted in water and poured into a sanitary sewer or septic tank (in other words, down the toilet) or in a leaching pit if you have no working toilet.
Body parts (amputations, skin removed from debridement, afterbirth, umbilical cords, etc) can simply be put in a latrine or buried deeply.
Safe chemicals to use for disinfection include bleach, hydrogen peroxide solutions containing natural oils, or a home-made solution made by mixing equal parts of white vinegar and hydrogen peroxide.
A hydrogen peroxide disinfectant:
Mix together only enough hydrogen peroxide and vinegar needed for one day in equal parts. Keep in a closed container. Pour a small amount on a cloth and scrub the surface to be disinfected. This mixture is best for use on tabletops, bed rails, and other surfaces.
Many places use bleach to disinfect surfaces as well, but care must be taken with it as it can splash into and harm your eyes and skin, and the fumes are dangerous to breathe.
One way to more safely use bleach is to use a ‘bleach bucket’ which is a outer container to hold the bleach solution, and an inner container or basket with many small holes to hold the wastes. (Any metal or plastic bucket or container with a strainer or even a wicker basket can be used as an inner bucket. A bleach bucket must have a tight fitting cover.
To prepare a ‘bleach bucket’, fill the outer bucket 1/2 full of a 5% bleach solution. Place a smaller inner container inside so the bleach passes through the holes. It should not float up. In this inner bucket, place the used bandages, cotton swabs, gloves, blood bags, etc. You may want to make 2 bleach buckets, one for items to be disposed of and one for items that can be re-used, like tools, equipment, etc. Cut up any items not intended for re-use before dropping them in the disposal bleach bucket.
Any bleach bucket should contain enough liquid to completely cover the materials, which should stay submerged for at least 10 minutes. The cover is both to prevent spills, and help the bleach solution hold its strength. Make a new solution daily.
How to make a disinfecting solution of 5% bleach
If the bleach says on the bottle it is 5% available chlorine, use just bleach.
If the bleach has 10% chlorine, add water in equal amount as the bleach.
For bleach with 15% available chlorine, add 2 parts water to 1 part bleach.
Mix just enough for one day; it will not be strong enough to kill germs after 24 hours.
Bleach is an effective disinfectant of laundered items. It is just as effective as the old carbolic acid wash that many hospitals used to use. That is not necessary. To disinfect bed linens and clothes, soak them in a bleach bucket for 10 min before washing with hot water and soap.
If you are concerned with Anthrax spores, which are notoriously hard to kill, know that they are killed by a combination of heat and moisture. Steam ironing letters (for example) with an iron set on linen and using lots of steam will kill the spores. The board can then be disinfected by using an acidulated bleach solution.
Acidulated bleach can be used for area or surface disinfecting. For counter tops and exposed surfaces, it is applied with a sponge or towel while wearing latex gloves. If it is used in a plastic pressure garden sprayer, it could be used to clean off driveways or vehicles! Clean it off after 10-15 minutes by flushing liberally with water because it will cause metals to rust severely. You can use soap and water to clean it off too, but no ammonia (ammonia will react with the bleach to produce mustard gas). The acidulated bleach solution kills everything from anthrax, to ebola, to smallpox, or other items.
To make acidulated bleach:
Mix 1 cup bleach with 1 1/2 gallons of water. Then add 1 1/2 cups of 5% vinegar. Mix in that exact order, in a plastic bucket if possible, and stir with a wood spoon or stick (this solution reacts highly with metals, so an aluminum pot should NOT be used.
Microwaving can disinfect medical wastes, but you must use a high power microwave. It is used for syringes, tools and certain wastes. Wear gloves and a mask and cut up items to ensure high-level disinfection. Put the waste in a non-metal container with water to cover. Put a light cover over the top to reduce the loss of water, and microwave for at least 20 minutes. Let the container cool, and dispose of liquid waste in a leaching pit or down the drain (it is disinfected liquid).
You can also boil, steam or pressure-cook materials for at least 20 minutes to disinfect. Start timing once the pot is fully boiling after you put in the items. Remove with sterile tongs or gloves and placed right away inside a disinfected container and sealed. The used water can be poured down the drain because the boiling disinfected it, too. Separate waste you treat this way from tools you are treating.
Steam disinfects gloves, masks and things made of metal and plastic. The steam must be kept coming for 20 minutes, although the water does not need to cover everything in the pot.
Pressure cooking disinfects metal, rubber, plastic and cloth items. Wash and rinse well to remove all visible dirt (the fancy medical name is ‘gross filth’) and when it looks perfectly clean, put the things in the pressure cooker, and add water. Cover, heat it up, and process at 15-20 pounds of pressure for 20 minutes.
After disinfection, the waste may be disposed of permanently. Burial pits are the most useful way. Do not fill waste pits with compostable items, reusable items (some disinfected glass and plastics), or items that can be sent to a landfill (disinfected plastics, cloth, bandages). If there is no local waste collection or local landfill, disinfected waste can be collected and put in a small waste pit on site, with a separate ‘sharps pit’ dug separately.
Locate the pit in an area where ground water is not near the surface, downhill from nearby wells and at least 50 meters away from rivers, streams, springs, and other water sources. Line the pit bottom and side with clay to prevent leaching of liquids. Build up a ridge of earth around the top to keep rainwater from running in. Make the pit and put a fence around it to keep people and animals away.
Each time the pit is used, cover waste with 10 centimeters of soil or a mix of soil and lime (to disinfect and repel animals). When the waste is less than 1/2 yard from the surface, cover it with soil and seal it with a layer of concrete at least 10-20 centimeters thick.
You can also seal sharps waste in containers with concrete. Place them in a hard container like a metal drum. When the container is 3/4 full, add a mixture of 1 part cement, 1 part lime, 4 parts sand, and 1/3 to 1/2 part water. Lime works as a disinfectant, and it also helps the cement flow into empty spaces to completely surround the waste. Seal the container and bury it in a trench or landfill.
Many places pour bleach, contaminated water or other liquids down the drain, which can be safe if the drain does not enter a stream. Dilute the liquid with a lot of water before dumping. But to protect water sources, it is better to dump them into a safe leaching pit.
To make a leaching pit:
In a place where ground does not flood and far from waterways and wells, dig a pit 18 inches to 3 feet deep. In the bottom put a layer of sand 2 inches deep. Then a layer of gravel 2 inches deep, and a layer of larger stones on top. Put a cover on it to prevent rainwater from getting in.
Bleach can be dumped into a leaching pit. Hydrogen peroxide solutions can be disposed of without special treatment.
To treat gutaraldehyde or formaldehyde for disposal, add caustic soda (sodium hydroxide) while checking the solution with litmus paper or a pH meter. The pH should be brought to 12 and stay at that pH for no less than 8 hours. After 8 hours, bring the pH to a neutral level (pH 7) by adding hydrochloric acid. (If you do not have the proper materials to make these chemicals safe for disposal, it is best not to use them or disinfectants using them!)
Disposal of antibiotics requires wearing gloves, safety glasses and a dust mask. Grind up the pills to a powder, mix the powder with cement, add water and form into solid balls. Bury these balls in a sealed waste pit.
Sterilization of disinfected materials is necessary for items you plan to re-use. Hopefully, you can stock enough items that you will have no need to re-use things. But safe disposal of contaminated medical waste is a good thing to know, just in case someone gets sick and requires home care in tough times.
A Community Guide to Environmental Health, upcoming Hesperian Foundation publication, Hesperian Foundation, 1919 Addison St, #304, Berkeley, CA 94704
“Using Bleach to Destroy Anthrax and Other Microbes”, EPA: Emergency Use of Bleach in Anthrax Decontamination
“Disinfecting Exposed Surfaces” Miles Stair End Times Report (internet)