The Environmental Protection Agency (EPA) defines disinfectants as the class of agents intended to destroy specific bacteria, viruses or pathogenic fungi on inanimate objects, but not necessarily their spores. A "hospital disinfectant" is such an agent shown to be effective against Staphylococcus aureus, Salmonella choleraesuis, and Pseudomonas aeruginosa, and may kill other pathogens as well.

Some substances with disinfectant properties include:

"Natural" products such as vinegar and baking soda don't work very well at killing microbes, studies show.

http://www.eurekalert.org/releases/uncc-scd012000.html
http://www.nwu.edu/research-safety/labsafe/cbsl/cbsl7.htm
http://www.ehs.ucdavis.edu/sftynet/sn-51.html
http://www.bhj.org/journal/1997/3901_jan/special_042.htm