Carbonyl sulfide Acute REL (μg/m3) 660 8-Hour Inhalation REL (μg/m3) 10 Last 8-Hour REL Revision 02/21/2017 Chronic Inhalation REL (μg/m3) 10 Last Chronic REL Revision 02/21/2017 Last Acute REL Revision 02/21/2017 Read more about Carbonyl sulfide