Hazardous Waste Management Manual – Waste Accumulation


The following section pertains to requirements for RCRA hazardous waste, i.e, waste that meet the RCRA definition, however some of procedures are used for the other types of hazardous and regulated waste.

Under RCRA, a hazardous waste accumulation area is a designated area where the hazardous waste is held and is sequentially accumulated for more than 24 hours such as NMSU’s accumulation area on ‘A’ mountain.

A satellite accumulation point is similar to the above except that it

  • is establishes for a process that generate the same or similar waste on a regular, on-going basis, i.e. not sporadic,
  • must be at or near the point of generation and be the location where waste initially accumulates (i.e. is not moved from one accumulation area to another)
  • can only be used to accumulate up to 50 gallons of hazardous waste or 1 quart of extremely hazardous waste and
  • must be under control of the operator of the waste generating process

While regulations allow hazardous waste to accumulate and/or be held up to 90 days at a central accumulation facility.  No duration is specified for a container in the process of being filled at a satellite area, however a full waste container must be moved to the central accumulation area as soon as possible after it is full (normally within 3 days).   Containers holding waste for less than 24 hours and/or attached to a process, which are filled automatically, are not included in this definition.

Hazardous waste generated by a NMSU activity must be held at an accumulation area and remains the responsibility of the generator until the waste has been properly identified, inspected, and accepted by EH&S .

Accumulation of hazardous waste containers in the laboratory and/or shop is regulated by law. It is important as a generator of hazardous waste to follow the guidelines outlined below:

  • All wastes generated in a laboratory or shop must be stored within the same laboratory or shop.
  • Do not allow wastes generated in another lab or area to be stored within your laboratory or shop.
  • Do not accumulate more than 50 gallons of hazardous wastes in any one location.
  • Ensure that all waste containers are tightly capped except when waste material is being introduced into them.

Generally satellite accumulation areas are established at locations near the waste generation activities for convenience and to lessen the risk of spillage by allowing transport of one large container rather than numerous small container loads to a central accumulation area.  Only one container and one waste stream may be in use at a satellite accumulation area at a time.

When necessary, hazardous waste may be held in small containers in individual work areas. The container must be: labeled with chemical name and the hazards and used only for the particular waste stream.  The container must be emptied according to the procedures defined in the following paragraphs

Accumulation Area Requirements

All NMSU hazardous waste generators (any activity, operation, or test that produces hazardous waste) are required to provide information on the waste they produce and quantities.  EH&S will inspect all collection sites and ensure the existence of appropriate conditions for safe chemical handling and collection prior to implementation of accumulation activities

NMSU will establish all satellite accumulation areas/points as follows:

  • Satellite accumulation areas will be located at or as near as reasonable to the generating activity or work place where hazardous waste, waste petroleum products, or used hazardous materials produced.
  • The accumulation areas must be located such that accidental spills and discharge will not flow into sanitary or storm water run-off systems.  Secondary containment must be provided if the accumulation area can not be isolated from the drain or run off area.
  • Indoor satellite accumulation locations will be designated with yellow and black safety tape and the area shall be identified with a sign specifying that it is a waste accumulation area and listing instructions for use and spillage. The containers will be placed within secondary containment pans or other support device (as designated).
  • Outdoor satellite accumulation points with bulk waste containers will use yellow and black safety rope/tape to segregate the area from the surrounding.  The area shall be identified with a sign specifying that it is a waste accumulation area and listing instructions for usage and spillage. Fifty-five gallon containers will set and remain on pallets or other special containment support at all times.
  • Large 55 gallon drums shall be labeled in accordance with 40 CFR. .Information on the specific wastes that may be placed in the waste container along with cleanup and personal protective equipment will be posted at or near each waste container.
  • For the larger containers an logbook will be provided for use with each container.  The log will be used to maintain a record of each time that waste is added to the container.  The log will be attached to and/or coded to the container by id and waste stream name.  Each entry must include: name of person adding waste, waste volume (gallons or convenient measure), and addition date

Accumulation Area Management

Each designated accumulation locations will have a primary and alternate monitor from and appointed by the waste generator accumulating the majority of the hazardous waste.  The names and phone numbers of the primary and alternate monitors will be posted at the waste container in the accumulation area

The waste generator is responsible for the proper accumulation, maintenance, and housekeeping of their satellite accumulation areas.  The waste generator and the accumulation monitor from each waste generating activity must ensure that:

  • Waste streams are not mixed. i.e. No waste other than the normal waste stream (approved for the container) is placed in the collection container.
  • The list of waste components is correct and complete for each waste container.  An accurate log will minimize analytical costs associated with disposal.
  • All leaks, spills, and releases are recorded and reported to EH&S .   Unless instructed otherwise, any release should be contained and cleaned up as soon as safely and quickly as possible.  Small leaks or spills around the bungs or openings of containers will be absorbed with absorbent material or rags. The materials used to pick up the spill will be disposed of as a solid hazardous waste and will be properly packaged and labeled.
  • Major leaks, releases, or spills sufficient to pose a threat to human health or the environment must be brought to attention of EH&S .  The accumulation monitor must ensure that all major spill are reported immediately and the appropriate evacuation action is taken.
  • Waste containers are to be filled to not more than 90 percent of the rated capacity of the container.  Fifty-five gallon containers must have at least 6 inches of freeboard.  This will allow sufficient free space to compensate for expansion due to heating.  Small containers must maintain sufficient freeboard for transportation and liquid transfer.  (Freeboard is the distance between the level of the liquid and the top of the container.)
  • Containers will be opened, handled, filled, emptied, and stored in a manner that avoids rupture or leakage.  Funnels will be used when adding waste to containers.  Funnels should fit securely in the container opening and must be compatible with the waste being entered.  Funnels shall be removed from container after transfer of liquid is complete.  Except when necessary to add or remove waste, containers must be kept closed.
  • Special procedures and/or separation may be required for some waste, e.g. ethidium bromide (see appendices for Standard Operating Procedures for these wastes)


Hazardous Waste Containers:

It is important to use the proper container when collecting hazardous chemicals in the laboratory. A chemical collected in the wrong container could pose a danger to laboratory personnel, EH&S personnel and university property. Container holding waste must be clean, in good condition, not leaking, and compatible with the waste being stored. Numerous accidents can be traced to the placing of hazardous material in unwashed containers that previously held incompatible waste.

EH&S has established the following guidelines for collecting waste chemicals:

  • Use a separate screw-top container for each hazardous chemical waste.
  • Use an appropriate container size to match the amount of waste generated.
  • All containers must be identified and appropriately labeled (see Labeling).
  • Containers holding waste must be in good condition, not leaking, and compatible with the waste being stored.
  • The container must always be closed during storage, except when it is necessary to add waste.
  • Hazardous waste must not be placed in unwashed containers that previously held an incompatible material (see compatibility chart – appendices).
  • If container holding spent hazardous material begins to leak, generator must transfer it to a container that is in good condition or manage the material to prevent potential for release
  • Incompatible materials and container holding incompatible materials must be separated or protected by means of a partition, wall or other device.
  • Container should be kept at or near the site of generation and under control of the generator.
  • Properly identified with completed waste sheets before pickup is requested.
  • Filled to a safe level (not beyond the bottom of the neck of the container or a 4-inch head space for 55 gallon drums).
  • All waste containers must:
    • Be clearly labeled with contents. Do not mark the container with the words “hazardous waste” or “non-hazardous waste”.
    • Use the waste/material tracking forms to list specific chemical constituents and amount of each.  This list should included all diluents (water, alcohol, etc).
    • If the container is reused container, then the old labels must be removed or painted over.

Note: Do not use Red bags, Sharps containers (Biohazard), or Asbestos bags for hazardous chemical waste collection.


Hazardous Waste Compatibility:

When more than one type of material is being discarded at one time, the integrity of the chemical compatible groups must be maintained.  Incompatible waste must be segregated.  For example, flammable liquids and other organics must be segregated from acidic and caustic wastes.  Never mix or pack together:

  • Acids with bases
  • Flammable or combustibles with oxidizers
  • Cyanides with other materials
  • Flammable with non-flammable solvents
  • Resins with the hardeners or catalysts

Partial lists regarding chemical incompatibilities, shock-sensitive compounds and potentially explosive combinations of some common reagents and common peroxide-forming chemicals are provided in the appendices.

Waste Segregation Guide

The following guidelines have been developed to assist in generating a well defined and separated waste stream.

  • Collect inorganic substances separately and do not mix solids with liquids unless the generation of a process waste is involved.
  • Collect halogenated and non-halogenated organic solvents in different containers.
  • Collect individual non-halogenated organic solvents separately; however, when they must be mixed, clearly indicate each constituent and state its percentage composition in the mixture.
  • Do not mix metals in with organic solvents. Such a mixture cannot be incinerated because of the metal or landfilled because of the organic solvent.
  • Recycle vacuum pump oil and do not mix with organic solvents or other chemicals. Indicate on the label and on the tracking form as “pump oil contaminated with other chemicals.” Uncontaminated pump oil may be sent to PPD Motor Pool for eventual recycling.
  • Contact EH&S for disposal of lab ware and equipment contaminated with acutely hazardous or toxic chemicals. This includes disposable laboratory items such as gloves, bench top coverings, pipettes, glassware, aprons, etc. As a general rule, clean and triple rinse other lab ware and dispose in the normal trash.
  • Do not put empty glass chemical containers directly into normal trash. Place in a box, mark “glass bottles” on the outside of the box, and, when full, dispose in nearest commercial dumpster.
  • Package any treated grain or similarly affected plant materials and contact EH&S for disposal. Sterilize any plant materials contaminated by a potential biohazard prior to disposal or pick up.

Segregation of non-hazardous and hazardous chemical waste has several advantages: the prevention of unwanted or potentially dangerous reactions, the protection of laboratory and EH&S personnel from potentially unsafe working environments, the ease in handling and disposing of wastes and the reduction of disposal costs.

Flammable Wastes

Drums containing flammable materials must be grounded and bonded to the waste collection containers before emptying the waste collection containers into the drums.



Empty containers of waste can be discarded as solid waste if they are properly managed. The prescribed management for an empty container varies depending on the type of waste. RCRA regulation defines an empty container and mandates its decontamination prior to disposal as solid waste. These guidelines are provided to assist you in defining and managing empty containers.

A container of hazardous (non-acute) waste is empty by regulation if:

  • All wastes have been removed using common practices for the type of container.
  • No more than one inch of residue remains on the container bottom.
  • If the container is
    • smaller than 110 gallons and no more than 3.0% residue by weight remains or
    • larger than 110 gallons and no more than 0.3% residue by weight remains in the container.

A container of acutely hazardous waste (see list of acutely hazardous materials) is empty if:

  • It has been triple rinsed with an appropriate solvent.
  • It has been cleaned by a method shown to be equivalent to triple rinsing.
  • The container has an inner liner which prevented contact between the container and the acutely hazardous waste.
Guidelines for Handling Residues
  • The residue in a RCRA “empty” container or liner is exempt from regulations (i.e., a RCRA “empty” container can be discarded as solid waste).
  • Rinsate from “triple rinse” procedures is hazardous waste and must be collected for proper disposal through EH&S .
  • Empty containers that have been rinsed are solid waste and can be disposed of in the trash can.
  • When “triple rinsing” containers, use appropriate quantities of solvent to minimize the generation of large volumes of waste.
Compressed Gas
  • Compressed gas cylinders are considered empty when the container pressure approaches atmospheric pressure.
  • Do not store cylinders for long periods without use.
  • If possible, purchase compressed gas only through the Physical Plant.  If you must purchase outside then buy from manufacturers that will agree to take the empty cylinder.
  • Small compressed gas cylinders (2 – 3 lbs.) which have been emptied can be given to EH&S, but the tag must be left on the cylinder for easy identification of the contents. These cylinders are usually returned to the manufacturer; however, some manufacturers are not accepting returned cylinders even for a fee.
  • When ordering lecture-sized compressed gases, please check whether or not they accept returned cylinders. If they do not, check with other vendors or consult with EH&S before placing your order. The handling and disposing of a single lecture-size cylinder can cost several hundred dollars. Label all empty gas cylinders with an “EMPTY” tag.


Proper labeling of laboratory material is essential for proper handling and disposal. In the laboratory, labeling helps minimize the generation of unknown chemical substances and facilitates disposal by EH&S . When preparing chemicals for pickup, use the following guidelines for labeling:

  • Use the Waste/Material Tracking Form provided by EH&S on all waste accumulation containers.
  • Use a permanent marker to mark out the wording on container or label (or remove label).   However the original container labels must remain on chemicals which are surplus or have reached their manufacturer’s expiration date because such chemicals have a potential for redistribution to other users.
  • Use proper chemical or common names in identifying chemical compounds.
  • Do not use chemical formulas, symbols or structural formulas to identify a chemical for the purpose of disposal.
  • List the active ingredients whenever a trade name or proprietary name must be used. This information is usually provided on the Material Safety Data Sheet (MSDS) or by the chemical manufacturer.
  • Properly label chemicals synthesized in the laboratory.
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