A substance or agent that can poison or cause degenerative effects in a developing fetus or embryo. The effects are generally similar to those an adult would suffer from exposure. This is closely related to a teratogen, which causes malformations of an embryo or fetus. Both fetotoxins and teratogens are reproductive toxins, substances which cause damage to one's reproductive and/or endocrine system and/or a developing fetus. Additional Info: A fetotoxin can cause developmental toxicity. The American College of Occupational and Environmental Medicine defines developmental toxicity as: The occurrence of adverse effects on the developing organism that may result from exposure before conception [pregnancy] (either parent), during prenatal[before birth] development, or postnatally [after birth] to the time of sexual maturation [puberty] . Adverse developmental effects may be detected at any point in the life span of the organism". Examples of developmental toxicity include fetal death, structural abnormalities or birth defects, and functional deficiencies or altered growth. In response to potential reproductive hazards and fetotoxins, the state of California (USA) passed a measure called the The Safe Drinking Water and Toxic Enforcement Act of 1986, which is better known by its ballot name, Proposition 65. This act attempts to regulate the use of potential fetotoxins and reproductive hazards. Further information can be found in the links below. MSDS Relevance: Always minimize the use and release of fetotoxins (or believed fetotoxins) in the workplace. If you are of child-bearing age, and must work with such materials, make sure that your employer implements workplace controls that minimize or eliminate your exposure. Better yet, See: If you can avoid working with such materials. See also: Mutagen, Carcinogen