We’ve received an increasing number of inquiries regarding spent resin’s toxicity, and to what extent the resin is subject to special hazardous waste regulations.  Because of this, we are now offering TCLP testing ( Toxicity Characteristic Leaching Procedure) to identify the eight heavy metals (Arsenic, Lead, Silver, etc.) of most concern to the EPA and state regulatory agencies. We also test for copper and zinc content.

If your resin is shown to be non- hazardous, the TCLP test is only needed once per year. the certified test results should be kept on file at your plant, available for review at any time.  If your resin is shown to be hazardous we will advise you of how to ship it as hazardous material for recycling.

 TCLP TEST

Congress has passed the Resource Conservation Recovery Act which sets the controls over these issues and gives the EPA responsibility to control industries and to set allowable threshold limits set for heavy metals. We are concerned with the limits set for heavy metals. The following chart lists the eight federally mandated metals and their individual limits. Copper and zinc are also shown, however, they are optional by state. It is important to note that individual states may pass more stringent limits but no state can pass weaker limits. To help you determine whether or not your resin contains any of these metals you simply have to review the metals you are cutting to see if these metals are present. If none of these metals are present, i.e. aluminum, then you know you are safe. If you are cutting material containing any of these, you would be wise to have a T.C.L.P. test done.

THE EPA LIST OF HAZARDOUS MATERIALS

It is of interest to note that of all the T.C.L.P. tests that we have done , we can count on one hand how many of them have failed. All of these failures occurred in Michigan after Zinc was added to the list.

If you decide to have a test made, make sure that it is done on resin that was used when EDMing your shop’s normal range of metals. The test must be done on spent resin. That is, at a time when you would normally replace it. The test results should be kept on file and are considered viable for one year- If your work materials don't change appreciably within that time frame. Should the EPA inspect your shop, the test results are considered "reasonable expectations".

Some larger EDM users, who test on a regular basis, have mentioned that upon occasion, their resin has tested hazardous. This seems to coincide with over-using the resin beyond the normal replacement time. For instance, EDMing a long roughing job, trying to get some extra hours from the resin even though it indicates replacement.

In either case, hazardous or not, the resin can still be recycled. However, non-hazardous can ship by any method, while hazardous requires special shipping procedures.

There is one important exception to all of this. The EPA has targeted six manufacturing processes as "Listed " as producers of hazardous waste. If your company is engaged in one of these processes then your waste is hazardous, period, no exceptions. You do not have to have it tested as it makes no difference, IT IS HAZARDOUS!!!!

I hope that our industry can operate properly and keep from being added to this list.

If your company is involved in one of the above and you operate an EDM machine, then the residual waste from the EDM machine is considered hazardous by the USEPA.

RESIN REGENERATION & DISPOSAL