EWG and Women’s Voices for the Earth filed a complaint in US District Court against the Food and Drug Administration and its “failure to act” on keratin hair straightening treatments, according to the group.    The summons will be filed today and a judge may also be assigned as soon as this afternoon.   High levels of formaldehyde make many keratin hair straightening treatments a serious health threat to both clients and salon workers. These treatments – often known by the popular brand name...