An official website of the United States government.

Due to a lapse in appropriations, EPA websites will not be regularly updated. In the event of an environmental emergency imminently threatening the safety of human life or where necessary to protect certain property, the EPA website will be updated with appropriate information. Please note that all information on the EPA website may not be up to date, and transactions and inquiries submitted to the EPA website may not be processed or responded to until appropriations are enacted.

We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Styrene Results - AEGL Program

Styrene      100-42-5     (Interim)
  10 min 30 min 60 min 4 hr 8 hr
ppm (12/12/06)
AEGL 1 20 20 20 20 20
AEGL 2 230 160 130 130 130
AEGL 3 1,900* 1,900* 1,100* 340 340


Lower Explosive Limit (LEL) = 9,000 ppm
* = >10% LEL
For values denoted as * safety considerations against the hazard(s) of explosion(s) must be taken into account.
Level of Distinct Odor Awareness = 0.54 ppm

IMPORTANT NOTE: Interim AEGLs are established following review and consideration by the National Advisory Committee for AEGLs (NAC/AEGL) of public comments on Proposed AEGLs. Interim AEGLs are available for use by organizations while awaiting NRC/NAS peer review and publication of Final AEGLs. Changes to Interim values and Technical Support Documents may occur prior to publication of Final AEGL values. In some cases, revised Interim values may be posted on this Web site, but the revised Interim Technical Support Document for the chemical may be subject to change. (Further information is available through AEGL Process).

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.