Pennsylvania is currently waiting for Gov. Tom Corbett to sign a bill that will officially ban animal shelter gas chambers, which are used to euthanize sick or overpopulated animals. The chambers would be replaced by drug injection performed by certified veterinary professionals. Death by gas chamber is a slow process, taking around 30 minutes for the carbon monoxide to take effect, and is also more costly than drug injection, which is a much faster method of euthanizing. If signed and approved, Pennsylvania will join 19 other states that have already banned the inhumane gas chambers in animal shelters. Some of the most populated states that outlaw the practice are California, New Jersey, and New York.