Regardless of Ledford's business interests, there are real problems with the highly toxic chemicals the workers are exposed to all day in this business - far more serious for the manicurists themselves then for their customers who are only exposed for a short periods of time - tho a customer who is pregnant or has  pulmonary or respiratory problems might want to think twice about exposing themselves.   I don't know what OSHA has to say about the responsibilities of nail salon owners and school operators – but perhaps the regulations are some sort of partial response to workplace health concerns.  Coal miners never used to worry very much about their respiratory health either as long as they had a good paycheck,until years later when black lung disease became an epidemic level  problem.