Incident or near miss – On 4/19/16 at ~6 pm, an undergraduate (hereafter referred to as “student”) and his girlfriend (not an MIT student) were in a professor’s office working on student’s UROP project, a robotic exoskeleton designed to increase vertical leap distance for the user. The student had been told that he was only to test the project with the assistance of a graduate student or postdoctoral researcher, but no one from the lab group was available that day. The thesis project was due very soon and the student needed data, so his girlfriend was assisting him. The professor’s office was used because it provided the high ceilings needed to test the project.
The girlfriend went to connect a makeshift plug assembly fabricated of 12 gauge electrical wire that was crimped and soldered on both ends. One end was connected to a LiPo battery pack consisting of 4, 4-cell 14.8 V 5000 mA•h packs wired together (reportedly in series), previously measured at a total of 66 volts. The other end was connected to motors on the exoskeleton project. The battery supplies and motors were previously used on another MIT project, and all wiring had been completed by a previous grad student in the group who is now no longer at MIT. This was the first attempt at using this source to power this project. As the male and female ends touched, there was a loud noise and the girlfriend screamed in pain. The floor was charred also.
Response action – The student escorted the girlfriend into the corridor; in the stress of the situation he was unable to find his MIT Police contact number and dialed 911. A neighboring student who heard the screams escorted them to a water fountain nearby (later to a bathroom sink) to provide cool water to her injured hand which was black in color. Another individual nearby called 253-1212 and MIT Police, EMT’s, and CFD responded. This resulted in transport of the injured person to Mass General Hospital where she spent the night due to (what was understood to be) a second degree burn between the first and second knuckle of the ring finger.
Immediate Cause – Short circuit at soldered joint between two wires when system was connected to battery pack
Causal factors (confirmed or suspected) –
- Having a joint at the location to be plugged (should have re-wired)
- Lack of strain relief at soldered connection in flexible cable (should have crimp connected)
- Use of makeshift plug (should have had better plug assembly or switch)
- Wiring done by someone else
- Wiring not checked ("approved?") by electrical safety/wiring expert
- Lack of training for student in general and on electrical safety and battery safety in particular (including EHS Rep not having knowledge of the student’s project)
- Lack of detailed, hands-on training and oversight of lab-scale electrical projects over a certain power level (and specifically electrical aspects of lithium battery safety) at MIT in general
- Lack of even rudimentary knowledge of experiment by injured party
- Non-MIT individual involved in MIT research
- Undergraduate student told to work only with grad student or post-doc, did not do so
- Time constraints / rushing to get data meant proper supervision not available
- Work performed in office rather than lab environment (high ceiling requirement could have been satisfied in a lab setting somewhere on campus)
- Work performed outside standard business hours (6 pm) (issue per PI)
- Project should not have been an undergraduate project to begin with (per PI in hindsight)
- Dialed 911 instead of 617-253-1212
- No calculation of potential instantaneous power from the system
Recommended corrective action(s) or lessons learned –
- Working Alone Policy doesn’t address level of knowledge that 2nd person must have.
Working Alone Policy doesn’t address two undergraduates working alone together.
- Suggest partnering with subject matter experts around the Institute to create
- short, relevant, useful lithium battery safety course
- hands-on, detailed, lab-level electrical safety course (if for nothing else to insure that users "know what they don't know" aka when to ask for help and who to ask)
- formalized way for competent professional (whatever that means) to review potentially hazardous lab electrical experiments
- Minimum training requirements for labs that have only physical hazards must be evaluated.
- It is certainly not the case that only those working in labs with chemicals need Lab Specific Training. However, that is exactly what current Training Needs implies, because there is no course called "Lab Specific Training," only one called "Lab Specific Chemical Hygiene Training" – which is only required when the activity "Work with chemicals" is checked off.
- (e.g. powerful batteries, UAVs, Collaborative Robotics, physical testing of materials, lasers, cryogens, hoists, water tanks, machinery/equipment, gas cylinders, pressure or vacuum vessels, 3D printers, laser cutters, ovens/furnaces, soldering, heavy objects)
- Examine MIT policy on non-MIT people participating in MIT research (at MIT or in the field).
What worked well – A neighboring student who heard the screams escorted them to a water fountain nearby (later to a bathroom sink) to provide cool water to her injured hand which was black in color. Another individual nearby called 253-1212 and MIT Police, EMT’s, and CFD responded.
Lessons Learned – See corrective actions