Commercial Fixed Wing
Maintenance Airframe; Maintenance Powerplant
Communication Breakdown
Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors
Upon completion of work on the aircraft; we boxed up our three pieces of tooling with no HAZMAT to return with us on the first ZZZ1 flight.  We attached the SLI (Shipper's Letter of Instructions) labels as required and moved them to the far left of the baggage cart that we were provided. We then moved the three hard containers with visible HAZMAT labels and no return paperwork on them to the far right of the baggage cart. We then took our escort over to the baggage cart and showed her the form and explained to her that the three boxes on the left of the cart with our tools and the SLI labels needed to be sent on the first ZZZ1 flight in the morning; and the three hard containers on the right side of the cart were labeled HAZMAT and needed to be sent through the freight house for HAZMAT shipping.  We then asked her if we needed to move the cart to a secure area and she said to leave it where it was.  We again; reiterated the importance of making sure the HAZMAT items were not shipped with our tooling; and asked her to make sure and leave a turnover if she was not going to be available in the morning. We still had to scan paperwork to Maintenance Control; and I failed to give her a copy of step 3A after confirmation from Maintenance Control that they received all documents.  After going through security in the morning we asked the Operations Agent on the ZZZ1 flight to confirm that our three boxes of tooling and only our three boxes of tooling were on the plane.  Due to TSA requirements; we are unable to go down to the ramp to confirm or review shipping procedures once we have been screened.
Air Carrier Contract Maintenance person reported improper shipment of Hazmat material due to a communication breakdown between maintenance and the shipping personnel.