B767-300 and 300 ER
Flight Crew Air Transport Pilot (ATP)
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Hazardous Material Violation; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Returned To Gate; General Maintenance Action
Procedure
During preflight we were notified of total dry ice of 1229 KG and a waiver was issued. Max without waiver is 966 kg. FO preflight and wore the CO2 detector. On pushback with packs off and starting engines his detector alarmed level 1 with .8 registering. Just to make sure it was not malfunctioning we turned the extra monitor on and it too alarmed. Told pushback crew to bring us back in gate and we shut down engines. Turned AC packs on and opened FOs window for ventilation as towed back in gate. Conferred with the HazMat specialist; maintenance; Ground operations; and Dispatch. Concluded to take off pallet position 3L which had majority of dry ice containing 861.7 kg. Continued on flight after receiving proper paperwork and redoing our preflight duties. No further issues.Excessive dry ice near cockpit causing monitor alarms to go off. I've carried a lot of dry ice using waivers and never had this problem. Not sure why this time it set alarms off. Prevention methods would be to carry less and maybe move it further back from flight crew; or in belly.
B767-300 Captain reported returning to the gate after the crew's CO2 detector alarmed because of a large quantity of dry ice that had been loaded under waiver.