Md-11 flight crew reported ACARS notification of unmanifested dangerous goods on board. At departure...

Narrative:

Blocked out of ZZZ 53 minutes late due to late inbound aircraft. Another MD11 was loading up beside us (aircraft Y); also bound for ZZZ1. The flight was normal; until I received an ACARS message from our dispatcher that there was undeclared hazardous material onboard in position 3L. I immediately made a sat phone call to dispatcher. He said they did not know anything other than it was class 9. He had spoken to the duty officer. My excellent (and probationary) first officer quickly brought up the relevant section of the fom; 10.25; under 'dg manifest modification.' after consulting with the dispatcher and the first office; I decided that; since there were no physical signs such as smells or smoke that would call for a divert; and that there was no other hazmat onboard that may create a separation issue; we would continue to ZZZ1 if the duty officer concurred. We would modify the dg manifest in-flight. I notified the dispatcher of this. He informed me later that the duty officer concurred with the decision to continue. In an abundance of caution we donned the CO2 detectors; as we were not sure what class 9 hazmat we were carrying. [We] received another ACARS. We were informed that the hazmat was some sort of 'safety devices.' we were in contact frequently with the dispatcher to see if there was any new information; but there was not. Landed uneventfully in ZZZ1.

Original NASA ASRS Text

Title: MD-11 flight crew reported ACARS notification of unmanifested Dangerous Goods on board. At departure; received no Dangerous Goods required documentation.

Narrative: Blocked out of ZZZ 53 minutes late due to late inbound aircraft. Another MD11 was loading up beside us (Aircraft Y); also bound for ZZZ1. The flight was normal; until I received an ACARS message from our Dispatcher that there was undeclared hazardous material onboard in position 3L. I immediately made a SAT phone call to Dispatcher. He said they did not know anything other than it was Class 9. He had spoken to the Duty Officer. My excellent (and probationary) First Officer quickly brought up the relevant section of the FOM; 10.25; under 'DG Manifest Modification.' After consulting with the Dispatcher and the First Office; I decided that; since there were no physical signs such as smells or smoke that would call for a divert; and that there was no other Hazmat onboard that may create a separation issue; we would continue to ZZZ1 if the Duty Officer concurred. We would modify the DG Manifest in-flight. I notified the Dispatcher of this. He informed me later that the Duty Officer concurred with the decision to continue. In an abundance of caution we donned the CO2 detectors; as we were not sure what Class 9 Hazmat we were carrying. [We] received another ACARS. We were informed that the Hazmat was some sort of 'safety devices.' We were in contact frequently with the Dispatcher to see if there was any new information; but there was not. Landed uneventfully in ZZZ1.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1677738
Time
Date	201908
Aircraft 1
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Instrument Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Person 2
Function	Pilot Flying First Officer
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Procedural Hazardous Material Violation Deviation - Procedural Published Material / Policy

Md-11 flight crew reported ACARS notification of unmanifested dangerous goods on board. At departure; received no dangerous goods required documentation.