Plastics, drugs and miracle fibers are just a few of the things that use chemicals in their manufacture. But chemicals have to be treated with respect, too. Many can cause injury or illness if not handled properly. Materials Safety Data Sheets are information documents about chemicals, their hazards and required protective and emergency measures. OSHA and the American Conference for Government Industrial Hygienists both published exposure limits that indicate the maximum of a substance that a person may breathe in a given period of time, without suffering ill effects.
Acute effects occur rapidly as the result of short term exposure, regardless of their severity.
Chronic effects usually occurs over a long duration and may not manifest except after long term exposure.