Kerosene

Kerosene is a chemical that Umbrella used to destroy Zombies.

The improper destruction of Zombies can trigger the t-viruses "back-up" system. This "back-up" - referred to as V-ACT - brings the creature back to life; with the added bonus of increased muscular density, whilst the cells in the body begin cellular reproduction, which recovers wounds and reverses the effects of rigor mortis. This creature is made worse with its ability to run along with the nails becoming claws.

Umbrella used this chemical - along with others - which, when set alight, burns the infected creature and stops the t-virus recovering.

The Arklay Research Facility, Spencer estate and a workers quarters began placing canteens of Kerosene around the area to stop zombies and raise workers morale, knowing that there was some way to save them.