The gas masks were found by Dr. Alan Grant and Robert Muldoon on the wall of the unmarked storage room on Isla Nublar. Grant and Muldoon took several of the masks, as well as some gas grenades, to the Velociraptor nest. Before entering the nest, Grant put his gas mask on over his face, in case the grenades needed to be used. Donald Gennaro did the same thing before entering the nest headfirst. When an adult Velociraptor approached Ellie Sattler, Grant could not set off a gas grenade because she had neglected to put her mask on before entering the nest. As the gas grenades were not used, the gas masks ended up being unnecessary.