Montag compares kerosene to at least a couple of different things over the course of the book.
The first comparison comes in the very first paragraph of the book. At that point, he compares kerosene to a snake's venom. He sees the hose as a snake and the kerosene as its venom. This seems like he sees kerosene as something dangerous and a bit evil.
But then, when he first meets Clarisse, he says something completely different. He says that kerosene is, to him, "nothing but perfume." This, clearly, is showing kerosene in a much more positive light.
So Montag seems to have something of a love-hate relationship with the stuff.