For more than half a century, FA has been widely used in Oxymetazoline hydrochloride resins, as adhesives and binders in particle boards, carpets and paints, as well as in the production of plastics, textile finishing, cosmetics, and insecticides. The International Agency for Research on Cancer and national agencies have classified FA as a human carcinogen. According to IARC, there is robust evidence of acausal link between FA exposure and the risk of nasopharyngeal cancer and leukemia. Indeed, FA exposure and the oxidative stress it induces are cytotoxic and potentially carcinogenic. Very few human studies have evaluated the effect of FA exposure onreproduction and development. Although controversial, some studies suggest reproductive and a Thiabendazole developmental toxicity in both humans and mice. A meta-analysis of 18 human studies provided evidence that FA exposure is associated with miscarriage and possibly with other negative reproductive out comes. For obvious ethical reasons, animal models are used to analyze the reproductive and developmental toxicity of formaldehyde. Male rats and mice exposed to FA present seminiferous tubule damage, decreased testosterone levels and decreased sperm counts, motility and viability. Female mice exposed to FA show hypoplasia of the uterus and ovaries as well as irregular estrus. Moreover, female rats and mice exposed to FA present an increase in fetal abnormalities such as embryo degeneration, chromosome aberrations and aneuploidy. The size of the placenta and corpus luteum are decreased, as are fetal weight and size. These observations support there productive and developmental toxicity of FA. The perfused human placental cotyledon model was used to study the kinetics of FA transfer across the placenta. This model is the only experimental technique which allows human placental transfer to be studied, an intact dual maternal-fetal circulation and placental tissue. We observed rapid transplacental transfer of formaldehyde from the maternal to the fetal compartment. The main mechanism of placental transfer is passive diffusion.