Here is some info on the website, it has a flamabiltiy rating of 2 and a flashpoint of 131 degrees.
CLEANS: WD-40 gets under dirt, grime and grease to clean. It also dissolves adhesives, allowing easy removal of labels, tape, stickers, and excess bonding material.
DISPLACES MOISTURE: Because WD-40 displaces moisture, it quickly dries out electrical systems to eliminate moisture-induced short circuits.
PENETRATES: WD-40 loosens rust-to-metal bonds and frees stuck, frozen or rusted metal parts.
LUBRICATES: WD-40's lubricating ingredients are widely dispersed and hold firmly to all moving parts.
PROTECTS: WD-40 protects metal surfaces with corrosion-resistant ingredients to shield against moisture and other corrosive elements