Date: 201904
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: B787 Dreamliner Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Communication Breakdown; Troubleshooting
Second reporter function: Technician
Anomaly: Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Maintenance
When detected: Aircraft In Service At Gate; Routine Inspection
Result: General Maintenance Action
Contributing factors: Human Factors; Procedure
Primary problem: Procedure

Narrative: Assigned to work Aircraft X with [another Mechanic]; due to vomit throughout plane at several seats. While checking plane and waiting for the seats to be addressed with [a vendor] to clean them. While looking at what needed to be done with addressing the cleaning it was noticed the above all the seats that had been vomited in there was an unknown substance sprayed all over the ceiling; the overhead bins throughout the galley as well.This again appears to be the pesticide that was referenced from upper management had said the planes had been sprayed with to kill bugs.After walking throughout the cabin looking at the numerous spraying and even runs of this unknown substance; by the time we had made the full run through the cabin this was leaving a bitter taste in the back of my mouth which was noticeable once I got out to the jet bridge for fresh air.As it turns out the log book had a write up of unknown substance in the forward and aft cargo but nothing about the cabin.Supervisor came out to see about the vomit and was shown the unknown substance and the log book was signed off as he had inspected the plane and said it was 'overspray of product during cabin cleaning' and then referenced a [Maintenance Discrepancy] without any inspection to verify the chemical or what the people are being exposed to.Cleaning or verification of this unknown substance needs to be removed and this could have been the issue of the people that had vomited inside of the plane; but since this is not being addressed people could be exposed without knowing what this chemical is.Suggestions: Exposure to unknown chemicals could cause long term issues in which nobody knows what is going on.

Callback: Reporter identified dried substance throughout cabin & galley areas. Repeat write up assigned Tracking number. Reporter experienced minor health symptoms.

Second narrative: I was assigned by my Crew Chief to work a couple interior PIREP items on Aircraft X. Also assigned is [another] mechanic. The aircraft arrived that day from [a] trip. The aircraft was taxied to [the] gate for trip that day. While working on the PIREPs assigned in the cabin; I noticed an unknown substance throughout entire cabin; including but not limited to overhead bins; ceiling panels; galleys and interior door trim. The color of the unknown substance is clear.The unknown substance film was sprayed inside the cabin all over and sprayed so thick that it ran down numerous ceiling panels and appeared to have dried in a run state in some locations. Lately numerous aircraft have been identified with an unknown substance in the cabin and cargo compartments. Looking in the logbook I noticed [a Logbook Deferral Sheet item a] Mechanic wrote up the forward and aft cargo compartments are covered in an unknown film. In our hazardous training [company] policy and procedure is to contact the Environmental Coordinator to identify the unknown substance and after knowing what the chemical is; consult with the products MSDS (Material Safety Data Sheet) before attempting to clean and release the aircraft back to revenue service. None of this was done. [Company] Management Supervisor came out to the aircraft. I showed him numerous areas that appeared to have been sprayed with the unknown substance and he signed off the aircraft logbook as inspected aircraft interior; condition observed consistent with over-spray of product during cabin cleaning process. Checked and approved for deferral per [Maintenance Discrepancy].


Synopsis: B787 mechanics reported unknown substance residue in cabin and galley area.