### MEMORANDUM
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REG N 5

To: 

### File

From: 

### Christopher Lambe is nvironmental Scientist, LCD

Date: 

### September 30, 2010 Subject: 

### Owosso delisting petition NMP sampling and analysis

This is a summary of sampling and analysis Owosso conducted for n-methyl 2- pyrrolidone (NMP) in their waste samples for a delisting petition.

Background: Owosso Graphic Arts conducts chemical etching of magnesium plates to produce photoengraved dies for the printing and foil stamping industries. A desired pattern is applied to a magnesium plate in the form of a printed laminate sensitive to ultra-violet (UV) light. After UV exposure, the magnesium plate is exposed to a spray of developing agent in a self-contained unit that washes away areas of laminate where etching is to occur. Owosso used the solvent trichloroethylene (TCE) as the developing agent until it was replaced in December 2007 with an aqueous solution (Hydro-Coat) containing inorganic sodium salt and a surfactant. The aqueous developer was used until September 2008 when Owosso began using the solvent n-methyl 2-pyrrolidone (NMP) as the developing agent. EPA determined that Owosso would analyze waste samples for NMP for inclusion in the DRAS risk assessment for the delisting petition.

Sampling and Analysis: Owosso collected four composite samples of the waste and one sample of the raw-product developing agent on March 9, 2010. The sampling of the raw product and waste filter cake is described in Owosso's submission to EPA dated June 4, 2010. Owosso sent these samples to Trimatrix Laboratories, Grand Rapids, Michigan, (Trimatrix) for NMP analysis by a modified SW-846 8270 method for tentatively identifies compounds (TICs). The laboratory diluted the raw product by a factor of 10,000 and analyzed the sample to determine the retention time of NMP by GC/MS in order to aid in the analysis of the composite samples.

Laboratory Quality Control: There were issues with some of the laboratory quality control results for these sample analyses. These problems are addressed in Owosso's June 4, 2010 submission and Trimatrix's revised narrative dated July 8, 2010. Generally, some of the internal standard and surrogate recoveries in the samples were out of control and below acceptable control limits. This happened because of high concentrations of oil and grease in the samples which leads to elevated chromatographic baselines masking the quality control analytes. EPA determined this explanation is sufficient and the data acceptable because the internal standard (1,4-Dichloronenzene-d4) used to quantitated NMP in the samples was in control and un-masked in all samples.Sample Results:

Sample Lab ID NMP (mg/kg) 1 st TIC

(mg/kg) 2n d TIC

(mg/kg) Total

(mg/kg) Total

dry wt. (mg/kg) Est.

TCLP (mg/L) Comp 1 1003152-03 0.4 2.56 2.41 5.37 15.79 0.79 Comp 2 1003152-04 ND ND 2.08 2.08 6.12 0.31 Comp 3 1003152-05 0.02 ND 5.35 5.37 15.79 0.79 Comp 4 1003152-06 ND ND ND ND ND ND

In order to achieve a conservative estimate of the NMP concentration in the waste, the
total NMP concentrations include the sum of concentration estimates from two other GC/MS peaks (where detected) in addition to the NMP analyte found at the approximate

retention time of 8.257 minutes. The 1S t TIC included has a retention time of approximately 7.825 minutes and has the same primary ion mass to charge ratio as NMP (99 m/z). The 

### 2 nd TIC included has a retention time of approximately 8.117 minutes and has the same secondary ion mass to charge ratio as NMP (70 m/z).

The estimated TCLP values are calculated by adjusting the total concentrations to dry weight concentrations using the minimum observed percent solids result (34%), and dividing by 20 to equal the dilution factor required in the TCLP extraction method. Using the DRAS software for this project, the provisional maximum allowable concentration for delisting is 734 mg/L TCLP. All observed concentrations of NMP analysis are well below the maximum allowable concentration.