According to the US Consumer Product Safety Commission, a yellow cap left on during the manufacturing process of models PI2010 and PI9010 can cover on the two smoke sensors, posing a risk of consumers not being alerted to a fire. In the United States 452,000 units are being recalled along with 40,000 in Canada. The specific affected units are:PI9010 (DC/battery powered) – Date code: 2016 Sep. 10 through 2017 Oct. 13PI2010 (AC/hardwired) – Date code: 2016 Sep. 10 through 2017 Oct. 13 Consumers should remove the alarm from the wall/ceiling and visually inspect it through the opening on the side of the alarm for the presence of a yellow cap. Consumers should not attempt to take apart the alarm, open the casing, or otherwise remove the yellow cap themselves. If a yellow cap is present, the consumer should immediately contact Kidde to receive instructions and request a free replacement smoke alarm. They should remove and discard the recalled smoke alarm only after they receive and install the replacement alarm. If no yellow cap is present, consumers should reinstall the smoke alarm and no further action is needed.