Requirements and laws for carbon monoxide detectors differ from state to state. NCSL table summarizes state CO detector regulations.
Amended rules for landlords on fitting carbon monoxide alarms
Carbon Monoxide and Smoke Alarm Legislation - Bartrop & Dilks
Carbon Monoxide Detectors: LL 191 Amendment
Are you compliant with smoke and carbon monoxide alarm regulations? - Total Landlord Insurance
Carbon Monoxide Alarms
Law a reminder to check your carbon monoxide detector, News
Carbon Monoxide Detector Requirements in California
Indiana Board Unblocks Local Carbon Monoxide Detector Rules
Carbon Monoxide Poisoning Poisoning Advice - Chim-Me-Sweep