Safe Disposal of Mercury Displacement Relays
Watlow developed this procedure for properly disposing of MDRs to
be a good steward of the environment and comply with applicable laws.
By returning your Watlow MDR to an approved mercury recycler you can
be sure that the MDR will be recycled or disposed of properly. However,
the recycler will charge a recycling fee.
Mercury Displacement Relay (MDR) - An electromechanical switching
device having one or more poles that contain metallic mercury and a
plunger which, when energized by a magnetic field, moves into a pool
of mercury, displacing the mercury sufficiently to create a closed
• MDRs must not be placed in the waste stream until the mercury
is removed for recycling.
Please contact Retrofit Recycling at 507-455-2181 or www.retrofitcompanies.com
to obtain a quotation for your recycle job.
MDRs eligible for this service are Watlow Series A, H, HG, KD, L, LD,
M and MD relays.
If the MDR you wish to recycle has one or more breached (open) poles,
you must seal it in a non-porous container to prevent the escape of
liquid and gaseous mercury. Acceptable non-porous containers are composed
of high density polyethylene, or equivalent.
Watlow recommends the relay(s) be double-bagged in sealed Zip-Lock®-type
storage bags and further sealed with heavy-duty packaging tape. Ship
the unit with adequate packing material in a corrugated cardboard
box (minimum burst strength of 20 pounds). Breached relays must be
as hazardous material.
Please include the following information on the hazardous material
Proper shipping name: Mercury contained in
Emergency contact number: 507-454-5300
Hazard Class or Division: 8
Identification Number: UN2809
Packing Group: 1 for air transport
Packing Group: 3 for ground transport
Type Label(s) and required information: Corrosive