Potassium Salts of Fatty Acids
Potassium salts of fatty acids provide "varying degrees of success" in killing moss, according to Oregon State University. These salts, which you mix with water and spray on the moss, are biodegradable but should not be used in areas with a lot of water, as they kill aquatic invertebrates. Use potassium salts of fatty acids in killing moss on lawns, decks and other surfaces. They are not harmful to metal.
Zinc is harmful to moss. It comes in a variety of applications, like zinc/copper sulfate mix that goes on dry or combined with water, liquid zinc chloride, zinc sulfate powder or liquid, or zinc strips physically attached to the area on which moss is likely to grow. This range of applications makes zinc a method of moss control that you can use on areas of moss within vegetation as well as on surfaces like wood or concrete. Effectiveness lasts for up to five years, depending on the application you choose, according to Oregon State University. These products are likely to kill fish, so take precautions to keep them from running off into a water source.
Household chlorine bleach kills moss on hard surfaces like roofs, decks and patios. You can also purchase bleach specifically for the purpose of killing moss. Thoroughly rinse bleach from the surface after you have killed the moss to avoid corroding metal surfaces or damaging other surfaces due to overexposure. Bleach keeps moss from growing for up to a year, according to Oregon State University, but it will likely kill surrounding vegetation and wildlife with which it comes in contact.
Baking soda mixed with water and sprayed on moss is an effective method of killing it, advises the University of Florida IFAS Extension. It may take a few days for the solution to completely kill the moss, but several days after application you should be able to brush it away if the elements don't take care of it for you. Avoid sprinkling baking soda directly on moss, as this can burn vegetation you wish to keep in the areas surrounding the moss, according to Ohio State University's Buckeye Turf website.