Is beer poison

No, it is not considered poison. OSHA and the EPA define toxic as substances with an oral rat median lethal dose (LD50) 500 mg / Kg or less, The DOT and IATA/ICAO use LD50, oral rat, 200 mg / Kg or less as the definition for poison for shipping hazardous materials and dangerous goods.

Ethyl alcohol, found at concentrations around 6% in beer has an LD50, oral rat, variously reported between 7060 to 12,000 mg / Kg.

Anything, though, can poison you if taken in large doses. There was a recent story of a woman who poisoned herself with water trying to win a Wii from a radio station's contest.

See Link.