Testing in 1963 showed that the TIARA 5 mixture had averse effects on the functioning of the C12 fuze integral to the M25A2 design. This led to the replacement of the fuze's integral primer, the M39A1, with a model that was resistant to the filler mixture, the M5. The EX 2 Mod 0, visibly more similar to other cylindrical smoke and chemical grenades (such as the AN/M8 and M18 discussed in this section) was designed to be used as a rifle grenade using the M2 series of grenade launcher adapters. The US Army also tested a plastic chemiluminescent grenade in 1966, utilizing the PB-155 filler and the M217 impact fuze, with negative results about the mixture's usefulness for the intended role, with the brightness and duration of functioning being "insufficient". In September 1942 the United States standardized a Molotov cocktail-style device that was nominally designated as a "grenade". It consisted of a pint-sized clear glass bottle with a crimped metal cap. It was dubbed "frangible" because it was made of glass, which is brittle and easily broken. The M1 grenade could be filled with any of a number of chemical compounds depending upon the effect required, in both lethal and non-lethal combinations. Most fillers were liquid compounds selected because they were activated by exposure to the air, thus not requiring a detonator. AC filler (Hydrocyanic Acid) was a blood agent. CNS (Chloracetophenone solution) was a tear gas made from CN gas (Chloracetophenone) dissolved in Chlorpicrin and Chloroform. M1 (B Chlorvinyldichlorarsine, or "Lewisite") was a liquid that turned into a powerful vesicant gas upon exposure that chemically burned the surfaces of exposed skin and lungs. The M6/M7 series were cylindrical riot control grenades, with a variety of fillers, including CN, CS, and DM. DM is a substance that causes a burning sensation in nose and throat and a heavy tight feeling in the chest, accompanied by a nauseating effect. All of these weapons are burning type grenades that work by burning the filler and emitting the resulting smoke through holes in the body. The M6/A1 is filled with CN-DM, the M7/A1 with CN, the M7A2 (also written ABC-M7A2) with CS, and the M7A3 (also written ABC-M7A3) with the CS in pelletized rather than gelatin capsule form.