By 1st Lt. Kaitlyn Barry, USAF, Jacob Denney, and Jeremy Slagley, Ph.D., CIH, CSP

Each year, the U.S. Air Force spends hundreds of millions of dollars to purchase materials that are necessary to support the execution of missions around the world. However, many of these materials have a shelf life that expires before they can be used, resulting in thousands of expired materials and millions of dollars in materials being unused and wasted. In addition to the money lost on procurement, the Air Force pays the Defense Logistics Agency (DLA) to properly dispose of the materials, many of which are considered hazardous waste.

While hazardous material disposal is an inevitability for the Department of Defense, potential cost savings are available. A recent study was performed at six bases within Air Force Materiel Command to look at what types of materials expire on the shelf regularly, and a short list of specific materials was collected to focus on to reduce the quantity of expiring materials and excessive spending. Recommendations can facilitate decision-making and inspire low-effort changes that could be made at installations worldwide, and directly impact costs of material procurement and disposal.

A KC-135 Stratotanker undergoes programmed depot maintenance at the Oklahoma City Air Logistics Complex at Tinker AFB, Okla. U.S. AIR FORCE PHOTO BY AIRMAN KIAUNDRA MILLER


The Materiel Command study focused on materials that could have their shelf life extended, otherwise known as Type II materials. Type I materials cannot be extended. From the broad description of materials, six stock classes of Type II materials were analyzed: chemicals, cleaners, paints, adhesives, sealants, and petroleum and grease. These expire in large quantities due to purchasing patterns and shelf life restrictions, and therefore, have the greatest cost-saving potential.

The six bases—Edwards AFB, Calif.; Eglin AFB, Fla.; Wright- Patterson AFB, Ohio; Hill AFB, Utah; Robins AFB, Ga.; and Tinker AFB, Okla.—were selected due to their similar missions and material procurements patterns. (These installations and all sites in the Air Force are partnered with DLA to supply and dispose of hazardous materials and waste items. DLA is responsible for procuring a significant majority of materials that the Air Force needs, as well as properly disposing of hazardous materials and waste after they leave the shops. This contract benefits the Air Force since DLA is held liable for any issues regarding improper disposal practices or procedures of the materials and waste they accept.)

The study considered how much the selected bases spent on procurement of materials in the designated stock classes from FY2016 to FY2019. This time span was selected in order to supply ample data on which materials commonly expired and resulted in a significant amount of money lost. While procurement data was available for a greater range of fiscal years, the Enterprise Environmental, Safety, & Occupational Health Management Information System database for disposal officially started in April of 2014, and it took about a year for bases to properly implement it.


There has also been discussion of a universal system that would allow bases to check what materials are available in the Air Force inventory, regardless of location, along with the remaining shelf life.

The six bases were separated into two categories: research, development, and testing (Edwards, Eglin, and Wright-Patterson); and maintenance and upgrades (Hill, Robins, and Tinker). The first step was to gather procurement data for each base from  the Logistics, Installations and Mission Support-Enterprise View. The information was gathered by people trained in the data management system and each file was organized the same way. The files included all the necessary attributes to classify the material, quantify the procurement costs, and note the qualities that had expired due to shelf life.

The disposal data was more complicated than the procurement data due to variations in the processes at each base as well as the accuracy and completeness of the data entered. The data for the study included the materials that were sent to DLA for disposal in addition to the materials that were transferred offsite. The data also varied considerably for the different bases due to the processes they used.

Information was organized and cleaned to remove irrelevant data, and then analyzed with each base separately and all six bases together. The bases listed eight main reasons why material was sent for disposition: damaged, excess, expired, lab test, mission changed, recalled, received expired, and unserviceable. A Pareto analysis was performed to locate specific materials that have high total procurement costs and were often disposed of through the waste disposal facility, as well as  the  materials  with a lower procurement cost that expired in vast quantities.


The study noted that certain bases have a significant quantity of expired materials in a particular year due to lapses in communication about deployment timing. Materials are ordered following normal procedures before the unit deploys, but then the materials are not used since the aircraft are not at the base. While this does not occur at every base, it demonstrates the importance of adequate communication between organizations. When a unit knows they are scheduled to deploy, this should be relayed to the logistics flight responsible for ordering the materials. Some materials will still be needed for ongoing tasks, yet the materials ordered should be proportional to the amount of aircraft and weapon systems still located at the unit. In a similar manner, the mission of a unit can change and require a new and different supply of materials. In the time leading up to the change, it is vital to communicate with all relevant parties so the materials already ordered can be used before the new ones to prevent an excess from expiring.

Another factor that leads to an increased quantity of expired hazardous materials is the minimum order quantity (MOQ) placed on some national stock numbers by DLA. The policy forces the base to buy more than they may actually need. For instance, a unit may only need four touch-up paint pens, but the supply unit of issue is a box containing 24 pens and the MOQ is four. The base must procure four boxes even though it only needs four pens that could all be from one box. This results in an excessive amount of expired materials each year. The MOQ imposed by DLA should be a target of further research, whereby some flexibility is given at the time of procurement. These contributing factors, in conjunction with improper shelf life management, materials arriving at the base with insufficient time for use, and excessive order quantities, all contribute to materials having an expired shelf life before they can be utilized for their intended purposes.


A potential method of reducing material waste is to repurpose materials that have an expired shelf life. It  is not uncommon   to buy similar materials for multiple-use cases. If a material is nearing the end of its useful life, it makes sense to repurpose   it. While certain materials are highly specialized, others have more general characteristics. This is already a precedent for some sealants, so the system would only have to be expanded.

There has also been discussion of a universal system that would allow bases to check what materials are available in the Air Force inventory, regardless of location, along with the remaining shelf life. This has a high potential for cost savings, since it would allow bases with similar missions to obtain needed materials that have already been purchased and are nearing the end of their shelf life. Even if the system were limited in the number of bases or materials, the cost saving potential is evident.

The most crucial step to addressing the problem is exposing it. If the underlying problems can be identified, small steps can be taken that will greatly reduce the amount of unused materials that have to be disposed of. Great Power Competition requires the Air Force to invest in cutting-edge research, development, and upgrades—this research highlights areas where money can be saved and re-directed to ensure the United States remains dominant on the global stage.

1st Lt. Kaitlyn Barry, USAF, is Graduate Student, Jacob Denney is Researcher, and Jeremy Slagley, Ph.D., CIH, CSP, is Assistant Professor, Air Force Institute of Technology. They can be reached at;; and

[This article first published in the Sept-Oct 2020 issue of The Military Engineer.]