M687 155 mm projectile

The M687 was an American 155 mm binary sarin chemical artillery shell.

Production was halted three years later, following the 1990 Chemical Weapons Accord between the United States and the USSR, and the dismantling of existing stocks began in November 1997 at Hawthorne Army Depot, Nevada.

The compartments were filled with two liquid precursor chemicals for sarin (GB2): methylphosphonyl difluoride (denominated DF) and a mixture of isopropyl alcohol and isopropyl amine (denominated OPA) is in a second canister.

The isopropyl amine binds the hydrogen fluoride generated during the chemical reaction.

When the shell was fired the force of the acceleration would cause the disk between them to breach and the spinning of the projectile facilitated mixing.