Narrative:

I served as pilot flying during this flight. Due to snow and frost on the wings; the aircraft was deiced prior to takeoff. SOP was followed for deicing procedures at ZZZ. Type 1 was requested and we (captain and myself) were informed they were using a 50/50 mix and we would not have the required 10 degree temperature spread. Type 1 and type 4 was applied to the aircraft. After application; the engines were run up for 20 seconds as per deicing SOP. The checklist was followed and we continued the taxi with the packs off. Captain ran the engines over 60% on the taxi in excess of 30 seconds on the taxi to runway xx. At the end of runway xx (8-10 minutes later) the packs were turned back on as part of the before takeoff checklist. We departed ZZZ straight out on runway xx and cleared present heading to join the SID. At 2;000-2;500 ft; the smoke toilet caution message came on. I called for the smoke toilet abnormal checklist and requested to level off at 7;000 ft. Captain ran the checklist while I handled the radios and the aircraft. As per SOP of the pom; I requested for a return to ZZZ. The flight attendant confirmed there was no smoke in the lavatory as per the pom checklist. I received vectors to return to runway xyc while captain completed the steps in the checklist. On the turn to the base leg; the message went out and a normal landing was conducted. It is unknown why this event has occurred. However; there have been numerous smoke toilet caution messages that have occurred as a result of glycol from the deicing process. I strongly suspect this was the cause of the caution message. This flight was a strong example of how a crew followed and exceeded the procedures designed to prevent this message and yet failed to prevent the toilet smoke message from occurring.

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Original NASA ASRS Text

Title: A CRJ200 flight crew experienced a 'smoke toilet' caution message after takeoff and returned to land at departure airport. Pilot Reporter suspects the warning may have been due to deice procedures and glycol in the air conditioning system.

Narrative: I served as Pilot Flying during this flight. Due to snow and frost on the wings; the aircraft was deiced prior to takeoff. SOP was followed for deicing procedures at ZZZ. Type 1 was requested and we (Captain and myself) were informed they were using a 50/50 mix and we would not have the required 10 degree temperature spread. Type 1 and Type 4 was applied to the aircraft. After application; the engines were run up for 20 seconds as per deicing SOP. The checklist was followed and we continued the taxi with the packs off. Captain ran the engines over 60% on the taxi in excess of 30 seconds on the taxi to Runway XX. At the end of Runway XX (8-10 minutes later) the packs were turned back on as part of the before takeoff checklist. We departed ZZZ straight out on Runway XX and cleared present heading to join the SID. At 2;000-2;500 FT; the Smoke Toilet Caution message came on. I called for the Smoke Toilet Abnormal checklist and requested to level off at 7;000 FT. Captain ran the checklist while I handled the radios and the aircraft. As per SOP of the POM; I requested for a return to ZZZ. The Flight Attendant confirmed there was no smoke in the lavatory as per the POM checklist. I received vectors to return to Runway XYC while Captain completed the steps in the checklist. On the turn to the base leg; the message went out and a normal landing was conducted. It is unknown why this event has occurred. However; there have been numerous smoke toilet caution messages that have occurred as a result of glycol from the deicing process. I strongly suspect this was the cause of the caution message. This flight was a strong example of how a crew followed and exceeded the procedures designed to prevent this message and yet failed to prevent the toilet smoke message from occurring.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.