Hazardous Waste Determination
This page will help you determine if a given waste material
must be classified as hazardous. The rules are spelled out in the Resource
Conservation and Recovery Act (RCRA), and in the large body of regulations
developed by the Environmental Protection Agency to implement RCRA.
It is important to know the correct classification of all of your facility's waste. The reason is that different sets of rules will apply to your facility depending on the total amounts of each type of hazardous waste that you generate per calendar month. Large quantity generators operate under more stringent rules than small quantity generators. The information on this page will help you determine what wastes to count toward the total.
Once you have determined the types and amounts of hazardous waste generated per calendar month at your facility, you will be able to find which rules apply to your facility by using the information provided on the page "Managing Hazardous (RCRA) Wastes" (see Generator status, EPA ID).
Please note that the regulations in your state may be different
in some respects from the federal regulations. Consult the HERC
State Hazardous Waste Locator to find more information on your state's
hazardous waste regulations.
Outline of the six steps
EPA recommends that you follow a six step process to determine
whether a waste is hazardous. The steps are listed below, expressed as
a series of questions:
The steps are discussed in some detail in the following sections,
with an emphasis on issues that would typically arise in healthcare facilities. Because
the issues can get complicated, the sections also provide links to more detailed
Is it "solid waste"?
The first step in determining if a material is a hazardous
waste is to determine whether it is classified as a "solid waste". The
rules specify that a material cannot be a hazardous waste unless it is first
determined to be a solid waste.
RCRA purposes doesn't mean what it means to you and me. The regulatory
usage of the term "solid" in this context is closer to the sense
of the word "contained".
“The term “solid waste” means any garbage,
refuse, sludge from a waste treatment plant, water supply treatment plant,
or air pollution control facility, and other discarded material including
solid, liquid, semisolid or contained gaseous material…” (US
Code, Title 42, paragraph 6903, emphasis added)
So even gaseous material can, in some circumstances, qualify
as a "solid waste".
Most materials of concern in healthcare facilities will fall
under the "other discarded material" category in the RCRA definition. So
how can you recognize when material has been "discarded"? According
to EPA usage, there are three types of "discarded" material:
- Inherently waste-like
Abandoned: In simplest terms, a material is considered "abandoned" if you plan to get rid of it. It clearly applies to material you have already disposed of, or that you have incinerated. It also applies to material that is being accumulated, stored and treated for eventual disposal.
It's not hard to imagine situations in which a facility and
an inspector might have a difference of opinion about whether some stored material
is or is not a waste. Here are some of the questions the inspector might
- Does the facility have a use for the material?
- Does the facility treat the material as if it was a valuable
- Does the facility plan to give it to someone else that
has a use for it?
For example, suppose the inspector comes across a 55 gallon
drum of solvent in the basement that is rusted, corroded and sitting in a pool
of water. Even if the solvent is a valuable commodity, the facility is not ‘treating’ it
as such. They are treating it as waste. The inspector would be likely
to consider it abandoned.
types of recycled materials are considered ‘discarded’ and are
therefore solid waste.
A material is normally considered to be discarded if it is:
- used in a manner constituting disposal
- burned for energy recovery
- accumulated speculatively
"Speculative accumulation" refers to all those
piles of material that you fully intend to recycle, but haven't quite gotten
around to. EPA will generally consider that your material is being "accumulated
speculatively" if you cannot demonstrate a viable market for it, or if
you have not recycled at least 75% of it in a given calendar year.
A material is also considered discarded if it is accumulated,
stored or treated before recycling.
Please note that some materials that are reclaimed are not
considered solid wastes under RCRA, even if they exhibit a characteristic of
hazardous waste (like ignitability or corrosivity -- see below). These
- commercial chemical products
Similarly, commercial chemical products that are speculatively
accumulated are also not solid wastes under RCRA.
Inherently waste-like: Certain materials pose
such a significant threat to human health that they are deemed "inherently
waste-like" and are always considered solid wastes. A standard example
is any material containing dioxins -- that is in fact the only example so far.
In case of dispute: It
can sometimes happen that an inspector will consider that a particular material
has been "discarded", and the facility will not agree. In
such a case, the facility will have to submit appropriate documentation to
the inspector. For example, if
you are claiming that the material is a valuable commodity or has another
use, you will need to show that you have a market for it, or that someone
is actually taking and using it beneficially, etc.
Is it excluded?
The next step is to determine if the waste qualifies for
an exclusion from RCRA regulation. There are three main avenues:
- solid waste exclusion
- solid waste variance
- hazardous waste exclusion
Solid waste exclusion: There are some materials
that are specifically excluded from the definition of "solid waste". You
can find a full listing in 40
CFR 261.4(a), but most cases are not likely to be relevant to healthcare
facilities. Examples include solid or dissolved material in domestic
sewage, certain nuclear materials (already covered under the Atomic Energy
Act), and a long list of materials from industrial and agricultural processes.
Regarding the case of domestic sewage, please be aware that
this exclusion does not give you an opportunity to throw questionable waste
down the drain and then claim that it's excluded under 40 CFR 261.4. The
purpose of that exclusion is to allow facilities like municipal sewage treatment
plants (known as "publicly owned treatment works", or POTWs) to deal
with their waste streams without having to comply with RCRA requirements that
would be inappropriate for them. Healthcare facilities must have a written
agreement from their POTW to accept any waste that might qualify.
Solid waste variance: Another possible way to
keep a particular material from being regulated under RCRA is to apply for
a solid waste variance. This option applies to:
- Materials accumulated speculatively without sufficient
- Materials reclaimed and reused within original process
- Materials incompletely reclaimed
In order to use these variances, you will have to submit
documentation demonstrating your case. If your state is authorized to administer
the variance program, send the documentation to the director of your state
agency. Otherwise, send it to the EPA Regional Administrator. You
can find the rules governing solid waste variances in 40 CFR, sections 40 CFR 260.30, 40 CFR 260.31 and 40 CFR 260.33.
Hazardous waste exclusion: Even if a material
is indeed a solid waste, and even if it does not qualify for a solid waste
variance, the regulations provide yet another possibility for exclusion. The
solid waste might be excluded from being considered a "hazardous waste" if
it falls under any of the exemptions listed in the next subsection of the Code, 40
Most of the hazardous waste exclusions listed in that subsection
are not relevant to healthcare facilities, but here are three possibilities
that may apply to you:
- Household waste (see 261.4(b)(1))
- Waste from university dormitories, military housing,
and any residents’s housing that you may have at your facility will
fall under this exclusion.
- However, note that only wastes normally found
in a household would fall under this exclusion.
- Note: if your facility hosts a mercury thermometer
swap for the community, this would be household waste and would qualify
for the exclusion, as long as that waste is kept separate from other
- Used Freon (see 261.4(b), paragraphs (11)
- Samples of solid waste collected for the purpose
of testing and treatability studies (see 261.4(d),(e), and (f))
Is it listed?
The RCRA regulations include four lists of materials, designated
with the letters F, K, P, and U. (The origin of the letter designations
is obscure.) If the waste you are screening appears on the any of the
lists, your task is done -- it's hazardous.
What distinguishes the lists?
The F- and K-lists cover
process wastes -- wastes generated from processes carried out in
your facility. The P-
and U-lists cover unused commercial chemicals that are being discarded for various
reasons; for example, they may be off-specification or expired, they
may have been spilled and cleaned up, or they may be residues left in containers.
The distinction between the two process waste lists (F and
K) lies in their specificity. The K-list deals with very specific processes
that are typically carried out by one manufacturing sector only, such as organic
chemical manufacturing or petroleum refining. The F-list covers general
processes that might occur in a range of sectors, such as solvent use, metal
finishing processes, and wood preserving.
The unused chemicals lists (P and U) differ in their degree of risk. P-listed wastes are "acutely toxic", meaning that they can cause death or irreversible illness at low doses. U-listed wastes are "toxic": they are still regarded as hazardous, but some of the more stringent regulations that apply to the P-list do not apply to U-listed wastes. It should be noted that the drug is only listed if its sole active ingredient is listed on the P or U list.
The P- and U-lists do not apply to manufactured articles
that contain a P- or U-listed waste (e.g. mercury thermometers) or to products
that contain more than one active ingredient. Such wastes might
still be hazardous, but their hazard classification would fall under a different
category (most likely the toxicity characteristic discussed in the next
Healthcare facilities do not carry out manufacturing processes,
and would not typically generate any K-listed materials.
The first five F-listed categories, F001
- F005, cover a range of solvents used in a variety of applications. A
healthcare facility might generate F-listed solvents such as acetone, methanol,
toluene, xylene, and methylene chloride from departments such as:
- pathology laboratory
- histology laboratory (xylene)
- maintenance shops (degreasers)
The rest of the F-list is not likely to apply to healthcare
If you are interested in reducing the hazardous waste generated
in your facility, eliminating or finding substitutes for P-listed chemicals
is a good place to start. A small quantity -- one kilogram -- of a P-listed
waste can cause a facility to be classified as a "large
quantity generator," and to have to comply with more stringent rules
as a consequence.
The P-list includes
about 239 different "acutely toxic" substances, listed under about
135 different waste codes. (Some codes cover several substances.) HERC
has identified 15 of these that you might expect to find in a healthcare facility. They
are listed below, along with their waste codes and typical uses associated
with each. The CAS numbers for these compounds can be found in the official
list at 40
Please note that our short list is not meant to be exhaustive,
and also that states may impose restrictions that apply to wastes beyond those
listed in the federal list.
P-listed chemicals commonly found in healthcare
| 3-benzyl Chloride
|| pharmaceutical manufacturing
|| veterinary medicine, severe parasitic diseases
| Arsenic Trioxide
|| pharmaceutical synthesis
| Cyanide Salts
|| emergency allergy kits, certain types of glaucoma, eye surgery, cardiac
|| smoking cessation, nicotine patches, etc.
|| coronary vasodilator in angina treatment
|| appetite suppressant
| Phenylmercuric acetate
|| bactericide, pharmaceutic aid in contact lens solutions and nasal sprays
|| acholinergenics (liberates/acts like acetylcholine)
| Physotigmine Salicylate
|| acholinergenics (liberates/acts like acetylcholine)
| Potassium Silver Cyanide
| Sodium Azide2
|| chemical preservative in hospitals, laboratories
||veterinary tonic and stimulant
1 Does not include epinephrine salts.
2 Special note on sodium azide (P105): Sodium
azide, found in Enterococcus agars, is also used in detonators and other
explosives. An odorless white solid, it s a rapidly acting, potentially
deadly chemical. It changes rapidly to a toxic gas with a pungent (sharp) odor
when it is mixed with water or an acid, or when it comes into contact with
certain metals (for example when it is poured into a drain pipe containing
lead or copper). But the odor of the gas may not be sharp enough to give people
sufficient warning of the danger. You should note that serious accidents have
occurred in laboratory settings. In one case, when sodium azide was poured
into a drain, it exploded and the toxic gas was inhaled.
3See EPA 2/17/2012 memorandum that clarifies the scope of the hazardous waste listing.
4For clarification, see EPA 3/18/2003 memorandum.
The U-list includes
about 472 distinct materials, listed under about 247 different waste codes. (As
with the P-list, the same code can refer to several different materials.) HERC
has identified 66 of them that you might expect to find in a healthcare setting,
and has listed them, along with their waste codes and typical uses, below. The
CAS numbers for these compounds can be found in the official list at 40
Our list is not meant to be exhaustive. States may
impose restrictions that apply to wastes beyond those listed in the federal
U-listed chemicals commonly found in healthcare
||solvent in pharmaceutical formulations
||sedative, hypnotic, antitussive
||anthelmintic, pharmaceutical formulations
||cough syrups, sleeping pills
||germicides, pharmaceutical manufacturing
||germicides, pharmaceutical manufacturing
||germicides, pharmaceutical manufacturing
||anticancer agent, contraceptive
||drug flavoring agent, topical anesthetic
||high level sterilant for surgical instruments
||antiseptic, disinfectant, preservative
||diuretic, heart and muscle treatment
||anthelmintic (anti-worm treatment)
||skin treatment (pHisoHex' Septisol')
||dialysis, pesticide (Septisol foam?) [note
ref to Septisol as hexachlorophene -no hits on "hexachloropropene
||preservatives (thimerosal), antiseptics (mercurochrome), devices (thermometers,
||solvent in pharmaceutical manufacture
||bactericide, pharmaceutical manufacture, pain control, anti-hemorrhagic
||antiseptic, anesthetic, antipruritic (relieves itching)
||hypertension, insanity, snakebite, cholera, horse tranquilizer
||acne, dandruff treatment, intermediate in pharmaceutical synthesis
||sugar substitute, food preparation
||inhalation anesthetic, pharmaceutical manufacture
|Warfarin < 0.3%
|2-Chloroethyl Vinyl Ether
||anesthetics and sedatives manufacture
Some chemicals used to treat cancer patients during
chemotherapy fall on either the U or P lists. These agents are often
referred to by their brand names rather than the chemical designations appearing
on the lists. For your convenience, HERC has compiled a list
of some common brand names, together with their chemical names and RCRA waste
codes. Please note that since new products may be introduced at any
time, the list may not include all brand names composed of RCRA listed chemicals.
Is it characteristic?
Designating hazardous materials by listing them explicitly
is fine as far as it goes, but that strategy will never go far enough. There
are many more materials used in commerce than could ever be covered in a manageable
set of lists. Furthermore, some mixtures of materials can be just as
hazardous as single materials, while others can be relatively benign. Given
the astronomical number of possible combinations of materials, listing is not
a practical way to account for mixtures.
To cope with these possibilities, RCRA provides another set
of criteria for classifying a waste as hazardous. Whatever its composition,
a waste is considered hazardous by RCRA if it exhibits any of four characteristics:
They are discussed in greater detail below.
Note: Even if a waste has been determined
to be a listed waste, it should also be evaluated to see if
it also qualifies as a characteristic waste. Additional rules may apply
to it in some cases.
Ignitable wastes pose hazards because they either catch fire
readily themselves, or (in the case of strong oxidizers) promote fires.
A waste is considered "ignitable" under RCRA if
- a liquid with flash point under 140oF, or
- a non-liquid, but susceptible to vigorous burning by friction,
water absorption, or spontaneous chemical change, or
- a flammable compressed gas, or
- a strong oxidizer
(The "flash point" of a liquid is the temperature
at which the vapor above a pool of liquid will catch fire under a standard
set of conditions.)
Ignitable wastes commonly found in hospitals include:
- rubbing alcohol (if the alcohol concentration
- certain mouthwashes including
Listerine' fall into this category
- silver nitrate
- certain topical preparations, such
- Cleocin T topical solution
- Erythromycin topical solution
- Retin A gel
- collodion based preparations
- certain injectable materials
The regulations covering the ignitability characteristic
can be found in Title 40 of the Code of Federal Regulations, Part 261, Section
Corrosive wastes include liquids with pH less than 2 or greater
than 12.5, or that corrode steel faster than a quarter-inch per year at 55oC.
Examples of corrosive wastes occurring in hospitals include
concentrated solutions of acetic acid or sodium hydroxide (lye).
The regulations covering the corrosivity characteristic can
be found in Title 40 of the Code of Federal Regulations, Part 261, Section
Reactive wastes include:
- materials that generate toxic gases in contact with water
- wastes that contain cyanide or sulfide and can release
toxic gases in contact with strong acids or bases
- explosive materials, or materials that are explosive
Reactive wastes that may be found in hospitals include:
- lithium-sulfur batteries
- dry picric acid
- explosive when dry -- should be handled with extreme
- may be found in histology laboratories
- a component of the tissue preservative Bouin's Solution
- nitroglycerin formulations (see
the HERC Pharmaceuticals page for more
information on nitroglycerin)
- ethylene oxide
The RCRA sense of toxicity is somewhat indirect. The
concern is not so much with the toxic properties of the wastes themselves as
with the extent to which toxic materials can leach out of the wastes if they
are exposed to water in the environment.
To measure this potential, the rules specify a test called
the Toxic Characteristic Leaching Procedure, or TCLP (EPA
Method 1311). The test is designed to give some indication of how
readily various materials would tend to leach into groundwater if the waste
were placed in a landfill. One form of the test involves subjecting the
waste to a mild acetic acid solution (about the strength of household vinegar)
at room temperature for 18 hours. The solution is then tested for the
presence of any of the so-called "D-listed" chemicals. For
each of the chemicals, the RCRA rules specify a threshold level (concentration). If
any of the chemicals is present in the solution at a concentration above its
threshold level, the waste is considered a toxic hazardous waste.
link will take you to the most recent available version of the complete
Examples of hospital wastes that are considered by RCRA
to have the toxicity characteristic include:
- mercury compounds, such as thimerosal, used as a preservative
- phenylmercuric acetate
- arsenic compounds
- barium compounds
- certain compounds containing other
Is it a mixture?
If a hazardous waste and a non-hazardous waste are mixed,
the resulting mixture may inherit the hazardous classification. The rules
are different for listed and characteristic wastes.
- Mixing in any amount of a listed waste
will cause the mixture to be considered hazardous.
- Mixing in a characteristic waste will cause
the mixture to become hazardous only if the mixture itself exhibits the characteristic.
There are various exceptions and exemptions
-- see, for example, the RCRA
Orientation Manual listed in the More Resources section for additional
information and references.
Is it derived from a
Similar rules apply to wastes that are derived from listed
or characteristic hazardous wastes as residues from waste treatment processes. Since
most healthcare facilities are not hazardous waste Treatment, Storage, and
Disposal (TSD) sites (and thus should be sending all hazardous wastes to a
licensed TSD facility), this consideration is unlikely to apply to them.
Related EPA Policy Memos
- Scope of Hazardous Waste Listing for P046 - Phentermine. Feb. 17, 2012 memorandum from EPA's Materials Recovery and Waste Management Division.
- Regulatory Status of Antineoplastic
Drug Wastes. This
letter is in response to a request for clarification of the status of certain
wastes. The request was for an interpretation of 40 CFR 261.33, with respect
to excess antineoplastic drug formulations which are not needed and thus
are discarded. (4/25/1988).
- Containers Used To Hold Listed
Chemotherapy Drugs. This letter responds to a question regarding the regulatory status of chemotherapy
drugs and related
supplies; in particular, the question whether the weight of the "empty" vial
should be included in determining the amount of drug residues to be disposed.
- Returned Pharmaceutical Products. This responds to a letter requesting
a determination regarding the regulatory status of pharmaceutical products
that are returned
by the dispensers of these products to the manufacturers, wholesalers,
or to a third-party service company that will facilitate the processing,
and, if needed, appropriate disposal of the returned products. (5/16/1991)
of Solid Waste and Reclamation. A distributor of a U-listed commercial
chemical product finds that the product is no longer saleable. (8/2005)
Pharmaceutical Products.' This responds to a letter requesting a
determination regarding the regulatory status of pharmaceutical products
that are returned by the dispensers of these products to the manufacturers,
wholesalers, or to a third-party service company that will facilitate
the processing, crediting, and, if needed, appropriate disposal of the
returned products. 5/16/1991
THERMOMETERS RECLAIMED OFF SPEC AND BROKEN.' This is in response
to a letter dated March concerning the regulatory status of off-spec
and broken mercury thermometers that are reclaimed under the Resource
Conservation and Recovery Act hazardous waste rules. 4/2/1986.
LISTINGS FOR COMMERCIAL CHEMICAL PRODUCTS MERCURY.' This letter
is in response to a telephone conversation and letter, both dealing
with waste listings for commercial chemical products (mercury thermometers).
- P AND U LISTED WASTES. This letter is in response to a letter, in which
someone asked for clarification of Resource Conservation and Recovery Act
(RCRA) regulations as they pertain to "U" and "P" listed wastes. (4/21/1989)
The definition of "solid waste" appearing
above can be found in the US Code. A different definition appears in
the Code of Federal Regulations 40
CFR 261.2. The US Code contains the text of laws passed by
Congress, while the Code of Federal Regulations contains the text of rules
written by executive agencies. The former is the definition most frequently
cited by EPA.
RCRA Orientation Manual https://www.epa.gov/hwgenerators/resource-conservation-and-recovery-act-rcra-orientation-manual