The objective of this Topic Area is to seek proposals to demonstrate and validate alternative cleaning methods and alternative solvents for use in the maintenance cycle of Department of Defense (DoD) assets, including cleaning and surface preparation, application, and removal of adhesives, sealants, and coatings.  

The alternative cleaning method and solvent alternative should have the following general characteristics: 

• Eliminate or significantly reduce the use of chemicals with risk evaluations under TSCA¹ for a targeted application.
• Reduce or eliminate the use of emerging chemicals of concern.²
• Not contain per- and polyfluoroalkyl substances (PFAS), perfluorinated oligomers, and polymers or other chemicals or materials that have been the subject of extensive replacement and/or cleanup efforts.³
• Reduce or eliminate hazardous air pollutant (HAP) content or reduce or eliminate their emissions.
• Reduce or eliminate volatile organic compound (VOC) content or eliminate their emissions. 
• Maintain low flammability or reduce flammability.
• Reduce the risk of harmful workplace exposures and the need for personal protective equipment (PPE).
• Cause no damage to or degradation of the substrate material.
• Alternative solvents for a targeted application must be compatible with the substrates used. Substrates include steel, aluminum, titanium, or magnesium alloys or polymer matrix composites, depending on the application. 
• Alternative solvents should be relatively safe with lower toxicity relative to the incumbent solvent.
• Alternative solvents should be scalable and relatively cost effective.
• Equipment for alternative cleaning methods should be able to fit within a DoD production line.
• Additional specific characteristics for targeted DoD application should be identified in the proposal, rationale for the alternatives to meet those requirements should be provided, and work to develop the solvents to meet those requirements should be proposed. Example key requirements are repainting effectiveness (time required and percent removal) and no increases in susceptibility to hydrogen embrittlement. 

The project must demonstrate that the commercial solution is focused on effective and sustainable resource management. The project must also demonstrate that the technology will result in reduced cost to maintain the weapons system or platform and have realistic initial acquisition costs.  

The materials and processes to be demonstrated should already be developed to a minimum Technology Readiness Level (TRL) of 4, and the proposed project should mature them to TRL 7 or higher. Field testing in military depots on general military weapons systems and platforms components, parts, sub-systems, or sections should be included in the proposed project. Alternative solutions should be production-level rather than laboratory. Projects must demonstrate producibility, defined as the ability to be produced in the near term to meet the current weapons systems and platforms requirements. 

Proposals should also include a plan to conduct an appropriately-scaled Sustainability Analysis^4,5 to inform financial decisions regarding incumbent and alternatives to aid in technology transition. 

Identifying and developing alternatives to currently used cleaning methods and solvents would reduce supply risk to DoD operations and lead to improved process sustainability, including reduced time and costs associated with personal protective equipment usage and facility controls. Reducing hazardous emissions can lead to increases in production throughput to enable increased readiness. 

Solvents are used in various aspects of the maintenance cycle, including cleaning and surface preparation, application, and removal of adhesives, sealants, and coatings. Solvent usage is applied to small parts, medium-sized parts, and large parts or sections of weapons systems. Cleaning can be performed via dip tank, vapor degreasing, spray applied, or hand applied via cleaning rag. Solvent-based coatings, adhesives, and sealants are applied by spray, caulk tube applicator, and roll on methods. Solvent-based coating removal can be performed via dip tank, spray applied, or hand applied. Adhesive, sealant, and coatings are typically governed by military or commercial specification requirements. Solvents that are chosen must be compatible with those specifications, or a path needs to be identified to enable revision of the relevant specification to enable use of alternative solvents.  

Examples of regulated chemicals and chemicals of concern that are used as solvents in relevant industrial operations include methylene chloride, trichloroethene (TCE), tetrachloroethene (PCE), dichloroethene, d-limonene, methyl isobutyl ketone, N-methyl pyrrolidone, benzene, toluene, and xylene among others due to their nature as HAPs or current or potential restrictions on their use.