The U.S. Army Environmental Center (USAEC) has developed a comprehensive program to identify the emissions resulting from range operations that involve weapons firing, smoke and pyrotechnic devices, and exploding ordnance and to assess the environmental and health hazard impacts resulting from their use. In the execution of the program, USAEC has identified four items—two of the colored smoke grenades, one white smoke grenade, and one of the smoke pots—that contain and emit toxic and carcinogenic compounds in significant quantities. These smokes and dyes may present a risk to soldiers, to nearby receptors, and to production and test personnel, especially in the hexachloroethane (HC)-filled grenades. It is in the interest of the Army and Department of Defense (DoD) to demonstrate and implement a material substitution for the dyes, smokes, fills, and starter patches in these specific munition items. Under this project, the functional and operational capabilities of these items with the alternative (less toxic) dye and smoke materials was validated prior to their implementation. Replacement has been implemented in other colored grenades but due to excessive flaring and inadequate burn rates, replacement has not occurred in the grenades to be changed under this project (red and violet M18 grenades).

The objective of this demonstration was to validate alternative materials/products so that they could be written into new military specifications (MILSPECS), including modified formulations of the smoke grenades to be used in manufacturing. The effort provided production and testing of four potential material substitutions for two smoke munitions items that are considered essential to Army training operations. The potential material replacements included: (1) the replacement of the dye in M18 red grenades, (2) the replacement of the dye in the M18 violet grenades, (3) an evaluation of the starter patches for use in the colored smoke grenades, and (4) the replacement of sulfur with a sugar-chlorate formulation. The production of the replacement for HC was not part of the detailed Demonstration Plan for this project but the success of the starter mixtures and patches will ensure future technical success of replacement efforts for HC mixtures in the munitions currently containing HC. This demonstration included the survey, testing and manufacturing of test, pilot, and production runs of red and violet smoke grenades to ensure they met the specifications of their predecessors and the safety requirements for soldiers to use them during training and also in active service.

This demonstration project sought to take existing technology from the M18 green and yellow smoke grenades and the M83 smoke grenade and combine them for the replacement of the dyes, sulfur, and other components of the M18 red and violet smoke grenades. The substitutions of a sugar-chlorate formulation smoke and less toxic dyes were successfully implemented for green and yellow M18 smoke grenades and for red, green and yellow 40mm projectiles. The red 40mm smoke grenade also was successfully transitioned to new materials. Similar changes to the red and violet M18 smoke grenades initially proved unsuccessful due to excessive burning of the dyes resulting in failure of the items to meet military standards for signaling. Later, with funding provided by the Environmental Security Technology Certification Program (ESTCP), reconfiguration of the red and violet M18 smoke grenades based on the M90 Light Vehicle Obscuration Smoke System (LVOSS) grenade utilizing redesigned starter patches proved more effective. The LVOSS grenade was fitted with a new starter patch in order to control excessive burning similar to that experienced with red and violet M18s. The patch slowed the starter mixture’s contact with the smoke mix allowing the temperature of the mixture to decrease, eliminating extreme flaming. This process was successful for both smokes; however, the transition to the red was not successful due to the coloration of the smoke being less red than required by MILSPECS. A cost comparison was done for current and new red and violet M18 smoke grenades. It was determined that the production cost increase for a batch of violet M18 smoke grenades in the new configuration can be attributed to the cost of the reformulated, and more expensive, smoke mixture. The opposite is true for a batch of red M18 smoke grenades. Labor costs are lower for both items. Testing of the M18s was conducted in accordance with Military Standard 810F at Pine Bluff Arsenal in Arkansas, DoD’s manufacturing facility for smoke grenades.

The USACE program was intended to make the material change completely transparent to the end-users, soldiers. The ammunition was tracked by the military Services by utilizing National Stock Numbers (NSN) and Department of Defense Identification Code (DODIC) numbers. Labels identifying “Reduced Sulfur Smoke Grenades” were placed on the wire bound boxes, metal cans, and fiberboard packing containers. Demonstrations encompassed two main areas: (1) the First Article test/standard lot testing for the corresponding smoke grenade and (2) a smoke grenade based qualification test. Upon completion and attainment of toxicity test requirements, an Engineering Change Proposal was submitted to the Configuration Control Board (CCB) for approval. The CCB makes the final determination as to whether the grenade meets all the standards of the Technical Data Package for procurement. Once approved for production and distribution, the grenade will replace the current M18 red and violet smoke grenade.