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Region 9 Laboratory SOP 239
Recycling Used Methylene Chloride
Summary
The purpose of this Standard Operating Procedure (SOP) is to describe the solvent recycling program at the EPA Region 9 Laboratory. This SOP will discuss the procedures for the recycling of "used" methylene chloride, or dichloromethane (DCM), using both the Integrity 2000⁜ and the B/R 8600⁜ High Purity Solvent Recovery Systems located in the BNA/GC-MS Laboratory, Room 402, to produce pesticide-grade methylene chloride. Procedures for completing the monthly solvent recycling report, as well as preventive maintenance schedules and procedures, will also be described in this SOP.
This SOP applies to the recycling of Aused@ methylene chloride which contains minor quantities (up to approximately 1%) of other constituents. Only "used" methylene chloride generated during the extraction of semivolatile, pesticide and total petroleum hydrocarbon compounds, during solvent recycling processes, and during the triple-rinsing of solvent bottles will be recycled.
Methylene chloride recycling will be performed daily by ESAT personnel when a sufficient volume of solvent is available for recycling. Recycling "runs" of a maximum of 9 liters using glass receivers or 18 liters using NowPak® receivers will be performed each day. However, both recycler units will be equipped for recycling up to 18 liters of solvent. The regenerated methylene chloride will be analyzed by gas chromatography (GC) with electron capture and mass spectrometry detectors to verify the purity of the recycled product. The total volume of "used" methylene chloride generated, recycled and recovered will be documented daily in the appropriate logbooks. This information is used to complete the solvent recycling reports which are submitted to the Laboratory Safety, Health and Environmental Manager (LaSHEM) on a monthly basis.