Pharmaceutical waste can result from many activities and locations in a healthcare facility. If you have a compounding pharmacy on-site, it generates drug waste. Anywhere medicines are employed can be the site of spills, half-used bottles, IV equipment with residual medicine on it. Waste drugs or pharmaceuticals can pose a special treatment and management challenge. Small quantities at households can often be thrown away in the municipal waste stream (perhaps with some makeshift method of denaturing or making the drugs undesirable to interlopers). Large quantities kept at pharmacies, distribution centers, hospitals, etc. must be managed to minimize the risk of release or exposure to workers and the public.
This category of waste includes expired, unused, and contaminated pharmaceutical products including vaccines and biological products used for therapy. Prescription and over-the-counter drugs end up as pharmaceutical waste as does paraphernalia used in pharmacies: gloves, masks, bottles, etc.
In the past, health care facilities would routinely flush waste pharmaceuticals down the drain. As a society, we didn’t know how detrimental these drugs would be to the environment. Now biologists have found residual pharmaceuticals in fish and the aquatic ecology and we are understanding how bad the untreated disposal of drugs is. As responsible citizens and waste managers, we need to keep the Precautionary Principle in mind.
Pharmaceutical wastes can be hazardous under RCRA, but in many cases, they are not. Solid pharmaceutical waste is generally easy to handle and package, but liquid waste poses more challenges in confining the waste and minimizing the risk of release.
Unused medicines in their original unopened packages can often be returned to the supplier you bought them from. This is a win-win. You don’t have to dispose of the drugs as waste and someone else who needs the medicine can use it.
Used transdermal patches. An increasingly popular way to administer medication is through a patch that sticks on the body and releases the drug through the skin. To maintain a more-or-less constant flowrate, the patch starts with substantially more medicine than it will ultimately deliver. A transdermal patch may contain 20 times the quantity of active ingredient the patient will get. After the patient removes the patch for good, it still has over 90 percent of the drug it started with.
Chemical Nature of Pharm Waste
Pharmaceuticals encompass a huge range of chemical compounds and they have all sorts of different effects on humans, animals, and plants. You need to be careful with all of them. Even aspirin should not be flushed down the toilet. Some medicines, such as those used to treat cancer, are outright dangerous (genotoxic or cytotoxic) and healthcare workers have to be protected from exposure.
Pharmaceutical wastes can be hazardous the same way many chemicals are. They can be easily ignitable, corrosive, or highly reactive. Additionally, pharmaceutical wastes can be irritants to body tissues.
Some drugs are genotoxic or mutagenic – aside from being dangerous to release to the environment, these can cause cancer and reproductive problems in healthcare workers. Medical facilities that deal with cancer treatment produce carcinogenic and/or teratogenic waste.
Treatment of pharmaceutical waste
There are exceptions for household waste, but enterprises (commercial and non-profit alike) cannot dispose of drugs by putting them in the municipal waste stream for delivery to a landfill. In the US, the EPA’s Land Disposal Restriction requires treatment of pharmaceuticals before disposal.
Treatment is aimed at changing the chemical structure of the medicines. The treated medicine should be acceptable for disposal with no worries of it getting into the ecosystem and harming people. While any number of chemical reactions could be proposed and systems devised to deliver those reactions (think of a giant artificial liver)., a more foolproof, all-encompassing solution is incineration.
Incineration induces chemical reactions, too. Combustion is the oxidation of anything that will burn, and most pharmaceuticals are organic compounds that will burn with sufficient temperature, oxygen, and time. A few drugs such as arsenic oxide are inorganic.
Many common drugs that do not fit the criteria for RCRA hazardous waste include antidepressants, antihypertensives, hormones, and antibiotics. Although there is no special requirement that they be treated before disposal, healthcare facilities that have these items in their waste streams generally want to treat them to reduce liability. These can all be incinerated. Some medicines are not ideal for incineration. Especially those with non-active ingredients that do not burn easily. Dietary supplements containing heavy metals are also inappropriate for incineration. These can probably be put in the MSW stream, but encapsulation is also an alternative and the waste manager may choose this alternative just to be sure and to reduce liability.
An incineration is thus an appealing option for the waste management engineer with a heterogeneous waste stream, as many streams with pharmaceuticals tend to be. Alkaline hydrolysis (mixing with a strong solution of sodium hydroxide) can also work on a wide range of pharmaceuticals. The system never gets hot and avoids the problems incinerators can come with (e.g. ash, acid gases in the flue stream, need to cool flue gas.) Because the reactants and their products do not go into the gas phase, the kinetics of the oxidation can be slower and inadequate mixing may limit the effectiveness of the destruction.
Alkaline hydrolysis is an un-nuanced blunt technology that destroys a lot of things. It is used to decompose animal carcasses. Given the unpopularity of incineration in many cases, the appeal of hydrolysis is clear. No air pollution, no chance of dioxin formation, no greenhouse gases, temperatures comparable to a kitchen (and hence less dangerous than an incinerator). For all practical purposes, both technologies affect that same level of sterilization. Alkaline hydrolysis results in a lot more secondary waste that must be dealt with – high pH liquid slurry and maybe solid residue versus incinerator ash. But there is also no air permit required.
Isolation/Encapsulation
Isolation leaves hazardous materials unchanged but prevents them from seeping into the environment. Encapsulation is accomplished with many plastics, resins, and even concrete. The medicines do not have to be removed from the packaging. The process of “inertization” is similar. Medication (pills, this is not often used on liquid medication) are removed from packaging and mixed into wet concrete. The concrete goes to the landfill. This isn’t perfect as it still allows leaching of the medicine in the landfill.
Remove the packaging from the pills (and that includes taking the pills out of blister packs). Grind up the pills and mix with lime and cement and water into a paste. The WHO recommends putting the moist paste into the landfill before it dries, but there appears to be no reason for that, It could be allowed to dry before transport to the landfill. In any case, this is thought to be safe enough to put into a sanitary landfill with municipal solid waste. Leaching is still a possibility, but if the landfill is a sanitary landfill, the chances of that should be reduced. (The WHO even recommends a ratio of 65 percent by weight medicine to 15 percent lime and 15 percent cement and 5 percent water.)
Denaturing pharmaceuticals
The UK government requires that controlled drugs be denatured before disposal. Denature means changing the physical/chemical characteristics so the drug is ineffective.
Pharmaceuticals as hazardous waste
Waste is considered hazardous because it either (1) contains materials on canonical lists – the F, K, P, and U lists – that are elaborated in the code of federal regulations, or (2) has the RCRA characteristics. The RCRA characteristics
- Ignitable
- Corrosive
- Toxic
- Reactive
The P-list includes eight chemical compounds used as drugs. These are “acutely hazardous” with a lethal dose (oral administration) of 50 mg/kg patient weight or less. The compounds are Warfarin (P001), Nitroglycerin (P081), Physostigmine (P204) and Physostigmine salicylate (P188), Nicotine (P075), Phentermine (P046), Arsenic trioxide (P012), and Epinephrine (P042). Waste Epinephrine is the most common of these in most hospitals.
The P-list includes 21 chemical compounds used as drugs.
- Mitomycin C U010
- Uracil mustard U237
- Streptozotocin U206
- Lindane U129
- Mercury U151
- Warfarin <0.3% U248
- Trichloromonofluromethane U121
- Melphalan U150
- Chloral hydrate U034
- Cyclophosphamide U058
- Phenol U188
- Paraldehyde U182
- Chlorambucil U035
- Diethylstilbestrol U089
- saccharin U202
- Dichlorodifluoromethane U075
- Reserpine U200
- Daunomycin U059
- Resorcinol U201
- Selenium sulfide U205
- Hexachlorophene U132
Chemotherapy medicines are notoriously dangerous, but only nine chemotherapy drugs are either P- or U- listed chemicals. These nine were in use in 1976. Therefore, over 100 equally hazardous chemotherapy drugs currently in use today are not identified federally as hazardous waste and are not subject to the RCRA Subtitle C requirements. However, a good deal of chemotherapy waste must be managed as hazardous waste.
Mineral preparations with heavy metals can be classified as hazardous waste.
Pharmaceuticals as non-hazardous waste
Medical waste managers often consider non-RCRA waste as hazardous waste when it contains pharmaceuticals even though this is not legally necessary. They are applying the precautionary principle and intentionally erring on the side of safety. Dangerous drugs are usually incinerated, as are waste antidepressants, antibiotics, and high blood pressure medications. Waste hormones and endocrine disruptors (from any source) cause concern and are often burned before final disposal.
Can I put pharmaceutical waste in my hazardous waste containers?
If you have a contractor that takes away your RCRA waste and they agree to take pharmaceutical waste, you can do this. However, it is not a “best practice”.
To know more, please check Malsparo.
