Montana State University

Safety and Risk Management

Montana State University
P.O. Box 170510
Bozeman, MT 59717-0510

Tel: (406) 994-2711
Fax: (406) 994-7040

Physical Address:
1160 Research Drive
Bozeman, MT 59718

Patrick Ryan

Hazardous Materials Manager
(406) 994-7803

How to Safely Accumulate and Store Chemical Waste

Choosing a Storage Location

Designate a specific location for the storage of chemical waste. Select a location out of the way of normal lab activities, but easily accessible and recognizable by Chemical Safety staff. Label the area with a "DANGER - HAZARDOUS WASTE" sign (available from Chemical Safety). Fume hoods may be used temporarily to store small quantities of waste materials, but should not serve as designated waste storage areas. Chemical Safety staff may ask you to assist them in removing waste from fume hoods, both for safety reasons and to avoid disturbing your experiments or processes.

Filling Out a Hazardous Waste Tag

An MSU Hazardous Waste Tag must be securely attached to your container at the time waste is first accumulated. Deface all other labels on containers you decide to use as waste receptacles. All of the following information must appear on the Hazardous Waste Tag:

  • Contact Name
  • Phone Number
  • Building and Room
  • Hazard Classification (flammable, poison, corrosive, etc.)
  • Date (when the first drop of waste was added to the container)
  • Chemical Name and Volume percent of each constituent totaling 100%
    • (non-hazardous components such as water should also be listed)
  • Age of Material
  • pH, if applicable; if not, use N/A

The accumulation start date must be entered when the first drop of waste is placed into the container. Wastes are to be listed by chemical name by percent volume in percentages as they are added to the container. Chemical names must be specific. Labels with nonspecific names such as organic waste, waste solvents, acid waste, etc. are not acceptable. Chemical formulas or abbreviated chemical names are not acceptable. Please list all pertinent information to assist Chemical Safety in properly managing your waste.

If a container is not properly tagged, Chemical Safety will not collect it. A Waste Refusal Notice pointing out the problem will be left at the waste storage site or posted on the door.

Selecting and Maintaining Containers

Make sure you utilize Chemical Safety containers or containers that are resistant to the chemical waste they will contain. In other words, you don't want chemicals to eat through or otherwise react adversely with the material the container is made of! For example, acids or bases cannot be transported in metal containers and hydrofluoric acid cannot be transported in glass. Call the Chemical Safety Facility if you have questions about compatibility.

All waste materials must be kept in secondary containers. Secondary containers can be lab trays, dishpans, or any container that will contain 50% volume of the waste.

The size of the primary container should correspond to the quantity of waste being discarded. For example, it is not cost effective to ship 50 ml. of material in a 4 L container. Store smaller quantities in smaller containers.

Liquids must be in a screw-capped container that will not leak if tipped over. Corks, parafilm, or lab beakers that will not stand on their own are not acceptable. When necessary, transfer waste material to a different container to comply with closure requirements.

Containers with liquid waste must be no more than 80% (Normal containers need 2" of headspace) full per Department of Transportation regulations and Chemical Safety processing requirements.

Liquid waste must not contain solids. Most liquids are transferred to drums after receipt by Chemical Safety and must be poured or pumped. Labware such as tubes, pipettes, stirring bars, etc., may not be placed in bottles containing liquid waste. The container will not be picked up if it contains any solids. Liquid containers found to contain solids during processing will be returned to the generator for separation. These items clog funnels and pumps and are not acceptable by the disposal vendors that receive our waste.

Solid contaminated waste materials such as glassware, gloves, paper towels, etc., must be in sealable containers suitable for transportation. Clear plastic bags must be used to allow visual inspection by the Chemical Safety waste handlers. If the contents cannot be visually inspected, it will not be picked up. The materials listed on the Hazardous Waste Tag should correspond to the contents in the bag (e.g., lab trash contaminated with trace amounts of phenol, absorbent contaminated with oil, etc.).

Containers holding materials that will be lab packed will not be returned. If you have a container you'd particularly like to have returned, consult with Chemical Safety before you begin using it for waste collection.

Chemical Safety will replace bulk liquid containers at time of waste collection. Chemical Safety periodically requires replacement of these containers. Chemical Safety does supply most of these containers as well as tags and labels.

Sharps and piercing objects include any device having acute rigid corners, edges, or protuberances capable of cutting or piercing skin or regular waste bags. Examples are: needles, razors, and scalpel blades; broken glass and plastic; pipettes, pipette tips,eppendorf tubes, capillary tubes; and sharp-cornered objects. Sharps and piercing objects must be placed in a rigid, leakproof container labeled with a Waste Tag.

Wipe down containers prior to your scheduled collection date. Containers must be leak proof and free of exterior contamination.

Segregating Incompatible Materials

Segregation at the point of generation is the key to safe, cost-effective waste management. Whenever possible, it is necessary to separate organics and inorganics for disposal purposes.

Segregate chemical waste by hazard class (e.g., flammable, poison, reactive, oxidizer, acidic, basic, or other). Follow basic safe storage procedures: keep flammables separated from oxidizers, acids from bases, cyanides from acids, etc.

*Note: Chemical Safety will not transport cyanides and acids together. If disposal of these chemicals is necessary, please clarify this information on the request form so arrangements can be made for Chemical Safety to collect these wastes on separate days.


Oxidizers react vigorously with reducing materials. The reaction can lead to fire or explosions. Keep oxidizers away from flammables, combustibles (such as paper or wood), and other reducing agents. Chlorine, for example, is an oxidizer; it should not be mixed with solvents such as acetone in a waste container. Not only is a reaction possible, but the material is then more expensive to dispose of.


Do not mix acids with any other chemicals for disposal. At no time should hydrofluoric acid be poured or mixed. List acid strength and solution pH on the Hazardous Waste Tag. Strong acids may be considered oxidizing agents; Chemical Safety personnel need to know the strength for these determinations.


Keep bases separate from all other waste. Do not mix acids and bases in the same waste container! Bases are corrosive and react violently with acids.


This waste stream can only contain elemental mercury, glass, or plastic. Please do not use sulfur, charcoal, or water during cleanup. All towels or debris should be segregated and labeled as mercury-contaminated debris. Double-bag mercury (metallic) thermometers in clear, plastic bags.

*Note: Mercury disposal is very costly. Consider using the alternative temperature measurement devices now available; they are accurate, biodegradable, and do not contain mercury.

Separating Solvents

Chemical Safety endeavors to use waste handling vendors that will recycle, redistill, or reuse wastes, but this can only be accomplished if the waste is as clean as possible. To boost MSU's recycling efforts; every effort should be made by the generator to keep incompatible waste separated. Laboratory personnel must separate halogenated solvents from non-halogenated solvents whenever possible. Current disposal procedures prevent us from mixing halogenated wastes with those chemicals sent for recycling as supplemental fuels. Halogenated solvents must be sent for direct incineration.

Do not mix solvents that have a high BTU value, such as ketones and alcohols, with low BTU solvents such as halogens, or those that have a high water content. High BTU materials can be recycled as fuel and are less expensive to dispose of than low BTU materials that must be incinerated as wastes. Store the materials in compatible containers, tag the waste, and identify the percentage of the material in the container (e.g., 33% acetone, 33% methanol, 34% hexanes).

Do not combine solvents with metals! Disposal is nearly impossible; and when it is available, the cost is exorbitant. Chemical Safety staff will not separate metals from solvents. These containers will be returned to the lab. Arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver also pose difficult disposal problems. Please call Chemical Safety for assistance if you use these compounds.

Chemical Safety presently sends used petroleum oils for recycle. Oils that contain mercury, lead, or other regulated metals cannot be managed in this program. All too often we find mercury or lead mixed with solvents after we have combined the solvent with other waste for incineration. If your oil possibly contains these materials, please notify us via the Waste Tag.

Deactivating Chemicals

MSU is not a licensed hazardous waste treatment or disposal facility. Therefore, operations that could be construed as hazardous waste treatment are not to be conducted at any MSU facility or laboratory without appropriate permits. Treatment is interpreted as any method, technique, or process that changes the physical, chemical, or biological character or composition of hazardous waste or material contained within, or which removes or reduces its harmful properties. Please contact Chemical Safety if you have questions regarding the deactivation of laboratory-generated wastes. Untreated waste should be stored and disposed of as indicated under each specific category in this publication.

Empty Containers

MSU is permitted to dispose of empty containers that are five gallons or less in the dumpsters if they meet the definition of the Resource Conservation Recovery Act (RCRA) empty container rule:

A container which previously held a hazardous material or waste is defined as empty if:

  1. 1. No hazardous material can be poured or drained from the container, or
  2. 2. No hazardous material remains in the container that can feasibly be removed.

The walls of the container must not contain any adhered or encrusted materials; however, a thin layer of dried material is acceptable. The Chemical Safety Environmental Management Facility advises the following procedures be followed:

  1. Make certain the container is EMPTY.
  2. Deface the label either by removing it, spray painting over it, or using a bold marker to deface it.
  3. Remove the lid.
  4. Place the container in the trash or dumpster.

Triple-rinsing is not required to comply with the RCRA empty container definition, but is a good practice for small containers.

*Note: If the container is greater than five gallons, attach a Hazardous Waste Tag to it, list the material that it previously contained, and request a waste pickup. List the container size in the special request section of the request form. Chemical Safety will determine whether it is hazardous waste or is suitable for recycling.

IMPORTANT: At no time should full or partially full containers, or any containers that do not comply with the aforementioned instructions be placed in the regular trash.

Mixed Infectious/Chemical Waste

Remember: CHEMICAL SAFETY will only pick up biohazardous waste that is cross-contaminated with either chemicals or radioactivity, or both.

Whenever possible, deactivate infectious waste at the source of generation. Contact the Biosafety Officer (994-4490) for approved methods of disinfection.


Chemical Safety will deal with unknowns on a case-by-case basis. In each case they must be labeled as an "unknown" with a MSU Hazardous Waste Tag. The generator is responsible for determining pH and age of the materials, and writing on the tag any other information that is known. This may include the type of lab (chemistry, organic or inorganic, biology, DNA research, etc.), and where it was found in the lab (under the hood with other organics, on a shelf with inorganics or salts, etc.). Chemical Safety Environmental Management Facility personnel will use HazCat field tests to identify the contents in the laboratory. Again, handling and disposal of unknowns is particularly expensive due to the great care with which they must be handled. Please make every effort to avoid unknowns by diligently labeling and dating inventory.


Chemically contaminated animals must be disposed of through Chemical Safety like all other chemical waste. Place them in clear, double plastic bags; seal each bag separately. Label each bag with a completed Hazardous Waste Tag, specifying the percentage of each chemical contaminant to the total weight of the animal. Weigh each animal, or group of animals--information that will help Chemical Safety determine the appropriate disposal method. Store them in a freezer.

In the case of preserved animals, separate the liquid preservative and the animal. Place the animal(s) in a clear, double plastic bag and label as "Animal Preserved in ________." Place the preservative in a container and tag it.

Gas Cylinders

With the exception of lecture bottles, all cylinders can be returned to the manufacturer for recycle and/or reuse--even if product is still in the cylinder. Returns are arranged through Chemical Safety.

*Note: Lecture bottles of compressed gases are extremely expensive to dispose of. The university owns both the container and the gas when the purchase is made. If you are certain the cylinder is empty and that the valve has not malfunctioned, write EMPTY in bold pen on both the label and the metal cylinder. Write EMPTY on the Hazardous Waste Tag and place it on the cylinder neck. Chemical Safety will remove the valve, deface the label, and send it to a metal recycler. If the cylinder is not empty, state on the Hazardous Waste Tag approximately how much product is left. Ensure all cylinders have a valve cap installed prior to collection.

Before purchasing a lecture bottle of compressed gas, ask the manufacturer if they will take the cylinder back, whether or not it is empty. Some do and some do not. If they do not, it is more cost effective to lease a larger tank from a local supplier.

If you have questions, call the Chemical Safety Team prior to purchasing a lecture bottle.


Many batteries are regulated as hazardous waste. Spent lead acid batteries, typically used in motor vehicles, are hazardous waste and should be tagged and disposed of through Chemical Safety. Other types of regulated batteries are lithium, nickel-cadmium, silver oxide, and mercuric oxide--regardless of size. Separate the batteries by type and place them in a bag or box. Identify the type of battery on the Hazardous Waste Tag and request a pickup as usual. Contact Chemical Safety if you have questions about other types of batteries.

Spray Cans

Spray cans still containing product are considered hazardous waste and must be disposed of through Chemical Safety. Place a completed Hazardous Waste Tag on the neck of the spray can and request a waste pickup from Chemical Safety.

Contaminated Materials

Materials, which have been contaminated with a hazardous chemical waste, must be handled, stored, and disposed of according to the guidelines in this booklet. Examples include; soil contaminated with oil, diesel, or other fuels; oilsorb; vermiculite; rags; sawdust; diatomaceous earth, and personal protective equipment. Contact Chemical Safety if polychlorinated biphenyls (PCBs) or large amounts of soil are involved.

Contaminated labware includes items such as plastic labware, kimwipes, towels, pipette tips, gloves, and containers less than five gallons that are contaminated with trace amounts of chemicals. Double bag these items in clear plastic bags and attach a completed Hazardous Waste Tag.

Chromatography Waste

Chromatography waste includes silica gel, alumina, safeties, glass spheres, glass wool, and sand contaminated with trace amounts of solvents and compounds. These materials must be dry and free of organic vapor odor. Drain columns for 24 hours prior to storage. Small quantities can be stored in double, clear plastic, bags. Seal each bag separately. Contact the Chemical Safety Facility if large quantities are generated so an appropriate container can be supplied.

Photographic and X-ray Fixer Waste

Fixers contain some silver, which must be treated or recovered before it can be disposed of. There are two options available for recycling this material. One is to have a commercial company service your photographic needs: typically, keeping your developer and fixer stocked and your waste removed. The second option is to have Chemical Safety collect the waste. Chemical Safety will dispose of the silver waste. If you have any questions, contact Chemical Safety for assistance.