The spermicide nonoxynol-9 has been claimed to reduce the likelihood of STI transmission. However, a technical report by the World Health Organization has shown that nonoxynol-9 is an irritant and can produce tiny tears in mucous membranes, which may increase the risk of transmission by offering pathogens more easy points of entry into the system. They reported that nonoxynol-9 lubricant do not have enough spermicide to increase contraceptive effectiveness cautioned they should not be promoted. There is no evidence that spermicidal condoms are better at preventing STD transmission compared to condoms that do not have spermicide. If used properly, spermicidal condoms can prevent pregnancy, but there is still an increased risk that nonoxynyl-9 can irritate the skin, making it more susceptible for infections.