Use of Environmental Forensics In Drycleaning Investigations
State Coalition for Remediation of Drycleaners
2009 Annual Meeting San Antonio, Texas
November 17-19, 2009
Robert D. Morrison, Ph.D. DPRA, Inc Hawi, HI
Forensic Issues in Drycleaner Investigations
• Apportionment in comingled plumes
• Date/age of a contaminant release
• Optimizing forensic sampling locations
• Forensic analytical program
• Cost
Presentation Outline PCE
Where to sample?
What to sample (media)?
Analytical decisions
Isolating the PCE source
Case study – multiple sources
Degradation Pathways of Four Chlorinated Solvents
Chemical names Carbon bichloride Carbon dichloride Ethylene tetrachloride Perchloroethylene Tetrachloroethylene
Trade names Ankilostin Blacosolve No. 2 Dee-Solv Didakene DowPer (Dow Chemical)* Isoform (Dow Chemical) Midsolv Nema Perclene (Du Pont, Diamond Shamrock) Perclene TG (Du Pont, Diamond Shamrock) Percosolv Per-Ex Perklone (dry-cleaning) Perm-A-Kleen Per Sec (Vulcan Materials) Phillsolv Tetracap Tetravec Tetropil Wecosol (Westinghouse)
* Manufacturer names in italics.
Synonyms for PCE
PCE Applications (a)
• Drycleaning (1960’s to 1980’s peak production years)
• Metal cleaning/degreasing – especially for cleaning aluminum parts prior to the development of TCA stabilized (1,4-dioxane) formulations
• Removal of wax and resin residue
• Cleaning of small, low-mass parts because the condensed solvent contact time is longer than for other solvents
• Automotive brake cleaning
PCE Applications (b)
• Rubber dissolution
• Paint Removal
• Sulfur Recovery
• Printing Ink bleeding
• Catalyst regeneration
• Textile operations as a scouring agent
• After 1966, primary use was in production of CFC-113 and HFC- 134a
TCE in septic tank cleaners
PCE can be present in TCE, particularly in degreasing grades because the two solvents are produced by the same process and are separated by fractional distillation. Other chlorinated compounds comprise 3 to 4 percent of degreasing-grade TCE.
The boiling points of PCE and TCE are 121.2 and 87.2°C, respectively. TCE degreasers usually use hot water somewhere below the boiling point of 100°C. Because of this difference in boiling points, TCE volatilizes into the air and is lost from the degreaser at a much more rapid rate than the PCE.
PCE Enriched via Solvent Distillation
REGENERATIVE FILTER ON A COOKER/STILL
AUTOMATIC BUMP
ASSEMBLY
SIGHT GLASS PRESSURE GAUGE
TEMPERATURE GAUGE
FILTER BODY
MUCK VALVE
HANDLE
CONTROL BOX
MOTOR
ACCESS DOOR
WATER SEPARATOR
CLEAN OUT DOOR
COOKER
STILL BODY
Company Approximate Period of Manufacture
Diamond Alkali/Diamond Shamrock 1950 ±1986
Dow Chemical 1923 ± present
E. I. Du Pont de Nemours 1933 ± 1986
Ethyl Corporation 1967 ± 1983
Frontier Chemical/Vulcan Materials 1958 ± present
Hooker Chemical/Occidental Chemical 1949 ± 1990
Hooker-Detrex/Detrex Chemical 1947 ± 1971
Pittsburgh Plate Glass/PPG Industries 1949 ± present
Stauffer Chemical 1955 ± 1985
Westvaco Chlorine 1940 ± 1945
Major Manufacturers of PCE
The primary production method for PCE prior to the 1970s involved the chlorination of acetylene to produce PCE/TCE. By 1978, acetylene production ceased.
Subsequent production methods used ethylene as a feedstock to produce ethylene dichloride (1,2DCA). In 1975, PCE production was 44% via propane chlorinolysis, 35% via 1,2-DCA chlorination and 3% by acetylene chlorination.
Feedstock used for PCE Production for Age Dating PCE
PCE/TCE Manufacturing Methods
The presence of 1,1,2,2-TeCA and/or 1,1,2-TCA with PCE suggests that the PCE was manufactured prior to 1978.
The presence of 1,2-DCA with PCE (eliminate its presence as a lead scavenger) indicates that the PCE was manufactured post 1978.
Chemical Name MW17S PBW-2 PBW-1 MW12D BD-17
VOCs Acetone < 0.0500 < 0.0500 < 0.0500 < 0.0500 < 0.0500 Benzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Bromobenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Bromochloromethane < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Bromodichloromethane < 0.0020 < 0.0020 < 0.0020 < 0.0020 < 0.0020 Bromoform 0.003 < 0.0010 0.016 < 0.0010 0.009 Bromomethane < 0.0098 < 0.0098 < 0.0098 < 0.0098 < 0.0098 2-Butanone < 0.0100 < 0.0100 < 0.0100 < 0.0100 < 0.0100 n-Butylbenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 sec-Butylbenzene < 0.0050 < 0.0050 0.007 < 0.0050 < 0.0050 tert-Butylbenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Carbon disulfide < 0.0100 < 0.0100 < 0.0100 < 0.0100 < 0.0100 Carbon tetrachloride < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Chlorobenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Chloroethane < 0.0100 < 0.0100 < 0.0100 < 0.0100 < 0.0100 Chloroform 0.0039 < 0.0002 0.034 < 0.0002 < 0.0002 Chloromethane < 0.0100 < 0.0100 < 0.0100 < 0.0100 < 0.0100 2-Chlorotoluene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 4-Chlorotoluene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Dibromochloromethane < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Dibromomethane 0.043 < 0.0050 < 0.0050 0.086 < 0.0050 1,2-Dichlorobenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,3-Dichlorobenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,4-Dichlorobenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Dichlorodifluoromethane 0.0036 < 0.0100 0.074 < 0.0100 < 0.0100 1,1-Dichloroethane < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,2-Dichloroethane < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,1-Dichloroethene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 cis-1,2-Dichloroethene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 trans-1,2-Dichloroethene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,2-Dichloropropane < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,3-Dichloropropane < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 2,2-Dichloropropane < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,1-Dichloropropene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 cis-1,3-Dichloropropene < 0.0010 < 0.0010 < 0.0010 < 0.0010 < 0.0010 trans-1,3-Dichloropropene < 0.0010 < 0.0010 < 0.0010 < 0.0010 < 0.0010 Ethylbenzene 0.0050 0.045 < 0.0050 < 0.0050 < 0.0050 Hexachlorobutadiene < 0.0100 < 0.0100 < 0.0100 < 0.0100 < 0.0100 2-Hexanone < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Isopropylbenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 p-Isopropyltoluene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Methyl tert-butyl ether < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 4-Methyl-2-pentanone < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Methylene chloride < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 n-Propylbenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Styrene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,1,1,2-Tetrachloroethane 0.09 0.007 0.78 0.0019 0.024 1,1,2,2-Tetrachloroethane 0.01 < 0.0050 0.4 0.002 0.002 Tetrachloroethene 0.155 0.047 0.523 0.145 0.067 Toluene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,2,3-Trichlorobenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,2,4-Trichlorobenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,1,1-Trichloroethane < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,1,2-Trichloroethane < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Trichloroethene 0.006 0.765 0.072 < 0.0050 0.015 Trichlorofluoromethane < 0.0100 < 0.0100 < 0.0100 0.0271 < 0.0100 1,2,3-Trichloropropane < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,2,4-Trimethylbenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 1,3,5-Trimethylbenzene < 0.0050 < 0.0050 < 0.0050 < 0.0050 < 0.0050 Vinyl acetate < 0.0100 < 0.0100 < 0.0100 < 0.0100 < 0.0100 Vinyl chloride < 0.0020 < 0.0020 < 0.0020 < 0.0020 < 0.0020 Xylenes, Total < 0.0150 < 0.0150 < 0.0150 < 0.0150 < 0.0150
EPA Method 8270 – Substituted Phenols
Where/What to Sample?
Where to Sample? Knowledge of Drycleaning Operation
Understand operational chronology, equipment chronology, filter material, distillation still, equipment location, ancillary services, building modifications/permits, sewer lines/connections, separator water connections, purchase/supplier records, equipment permits, insurance records.
Visit Site Prior to Sampling
Identify piping, flooring, joints (wood, oakum, felt), sewer cleanouts, storm water, dumpster locations.
Knowledge of Equipment and Handling Practices
Traditional v. Forensic Sampling
Traditional – Soil, soil gas, groundwater
Forensic – Muck, sewer pipe, flooring, expansion joints, filter material, asphalt/concrete paving
Florida Drycleaning Solvent Cleanup Program on reported spills, leaks and discharges of drycleaning solvent and solvent-contaminated wastes at 334 drycleaning facilities and 14 drycleaning wholesale supply facilities located in Florida.
Optimizing Sampling Locations
Sources of Muck
Knowledge of Operations
Product Description Ingredients Percentage by Weight
Leather Spray Blue F2000 Diisolbutyl ketone 2,6-dimethyl-4-heptaone 28.5 Butyl Cellosolve 2-Butoxyethanol 4.8 Titanium dioxide 2.2 Dibutylphthlate 1.8 2-propoxethanol 1.4
Leather Spray Blood Red F2000 Diisolbutyl ketone 2,6-dimethyl-4-heptaone 28.9 Dibutyl phthlate 1.8 2-propoxyethanol 2.2 Butyl cellosolve 2-butoxyethanol 9.2 Castor Oil exthoxylated 1.4
Leather Spray Pure White F2000 Titanium Oxide 18.1 Butyl cellosolve 2-butoxyethanol 8.5 Diisolbutyl ketone 2,6-dimethyl-4-heptaone 25.1
Leather Spray Orange F2000 Diisolbutyl ketone 2,6-dimethyl-4-heptaone 28.3 N-butyl Alcohol 1-Butanol 1.2 Disbutyl Phthlate 1.6 Butyl cellosolve 2-butoxyethanol 8.7
Surrogate Chemical Signature Associated with Leather Finishing at a Dry Cleaner
Morrison, 2003. PCE contamination and the dry cleaning industry. Environmental Claims Journal. 15(1), 93-106.
Sediment/Muck in Cracks and Expansion Joints
Cracks/Multiple Pours
Muck from Expansion Joint Material (high probability sample)
Dry Cleaning – Filter Aids Activated Carbon
Bone Char
Diatomaceous Earth
Attapulgite Clay
Cationic Polymer Coater Anionic Type
Diatomaceous Earth Filter Activated Carbon Filter
Surrogate - Dry Cleaning Filter Material + PCE for Age Dating
Case Study Expansion Joint Sampling
Expansion Joints
SEM of Paint Flakes and Rust
Sewer Videos – Sewer Sampling
Trial Graphic Depicting PCE Sources at a Dry Cleaner
Analytical Decisions
Understand the question - then
develop the analytical program.
Forensic Techniques for PCE Investigations at Dry Cleaners
Additives (inhibitors, anti-oxidants, etc)
Surrogate chemicals and materials
Degradation rate approach (half-life rates)
Molar ratio approach
Isotopic analysis (soil, groundwater, indoor air)
PCE Stabilizers
Acid Inhibitors Acetylenic alcohols Acetylenic carbinols Acetylenic esters Alcohols Aliphatic amines Aliphatic monohydric alcohols Amides Amines Azo aromatic compounds Epoxides Hydroxyl aromatic compounds Ketones Nitroso compounds Pyridines
Metal Inhibitors Alcohols Aromatic hydrocarbons Cyclic trimers Esters Lactone Oxazoles Oximes Sulfones Sulfoxide
Light Inhibitors Amines Cyanide Hydroxyl aromatic compounds Nitriles Organo-metallic compounds
Antioxidants Acetylene ethers Phenols Pyrrole Thiocyanates
Stabilizers and PCE (synoposis)
Unlike TCE and TCA, PCE is relatively stable and requires only minor amounts of stabilizing additives to prevent decomposition. Earlier stabilizers included amines and hydrocarbons; more recent stabilizers include compounds such as morpholine derivatives. In the presence of water, unstabilized PCE will slowly hydrolyze to form trichloroacetic acid and hydrochloric acid.
Is TCE a PCE degradation product ?
TCE – Some Similarities(yellow) /Differences (white)
Acid Inhibitors
Acetylenic alcohols Alcohols Aliphatic amines Aliphatic monohydric alcohols Alkaloids Alky Halides Amines Azines Azirdines Azo-aromatic compounds Epoxides Essential oils Hydroxyl-aromatic compounds Nitroso compounds Olefins Organic Substitute NH4 hydroxides Oxirane Phenols Pyridines Pyrrole Quatenary Ammonium compounds Terpenes
Antioxidant
Amides Amines Aromatic carboxylic acids Aryl stibine Boranes Butylhydroxyanisole Phenols Pyridines Pyrrole Thiocyanates
Light Inhibitor
Aromatic benzene nuclei Boranes Ethers Guanidine Hydroxyl-aromatic compounds Organo-metallic compounds
Metal Inhibitors
Alcohols Amides Amines Aromatic hydrocarbons Complex ethers and oxides Cyanide Cyclic Ethanes Cyclic trimers Epoxides Esters Ethers Ketones Olefins Peroxides Pyridines Oxazoles Oxazolines Oximes Sulfones Sulfoxide Thiophene
TCE
TCE Stabilizers Metal stabilizers used with TCE include 1,2-butylene oxide and epichlorohydrin.
Epichlorohydrin was discontinued in the 1980s due to its toxicity. Accumulate in still bottom residue “muck” up to 35% greater than their original composition in TCE.
TCE
Stabilizers used in Dry Cleaning PCE
Early PCE stabilizers included amines and petroleum hydrocarbons; more recent stabilizers included morpholine stabilizers.
Stabilizers used in dry cleaning grade PCE include 4-methyl morpholine, N-butyl glycidyl ether (best marker), cyclohexane oxide, diallylamine and 3-methoxy proprionitrile.
Manufacturers of PCE for Dry Cleaning and Associated Stabilizers
Dow Chemical 4-methyl morpholine
Vulcan Diallylamine/tripropylene compounds
PPG Cyclohexene oxide, beta-thoxyproprinitrile, m-nethyl morpholine, 4-methylphenol
Distinguishing Drycleaner from Transformer/Metal Cleaning PCE (a)
PCE was used in transformers as a replacement for the more toxic class of dielectric fluids containing PCBs.
PCE used as a dielectric fluid was subjected to extra refining including scrubbing and distillation and was stabilized with n-methyl pyrrole (112 C) and pentaphen (p-tert amyl phenol) (226 C).
Drycleaning grades of PCE did not use n-methyl pyrrole or pentaphen. May use the presence of these two stabilizers with PCE to distinguish PCE originating from a drycleaners from one originating from a transformer.
Patent literature indicates that metal degreasing metal cleaning PCE used n-methyl pyrrole as an oxidant containing 0.022 to 0.028% stabilizer and not for dry cleaning.
N-methyl pyrrole was also used to stabilize TCA and TCE; pentaphen used to stabilize TCE against oxidation.
Distinguishing Drycleaner from Transformer/Metal Cleaning PCE (b)
Stabilizers in Drycleaning Grade PCE
Stabilizers in PCE for Transformers
4-methyl morpholine diallylamine tripropylene compounds cyclohexane oxide 3-methyl proprionitrile n-butyl glycidyl ether
p‐tert amyl phenol (pentaphen) n‐methyl pyrrole
Metal Cleaning v. Dry Cleaning (a)
Metal Cleaning Traditionally contained a higher concentration of additives than most dry cleaning grades. Classes include acid acceptors, antioxidants, and UV stabilizers. Antioxidants include amine or phenolic compounds 50 – 200 ppm and acid acceptors epoxide 0.2-0.7%. Early PCE formulations included alkylamines and other hydrocarbons. Later stabilizers included morpholine derivatives, epoxides, esters and phenols.
Dry Cleaning Traditionally contained a high concentration of additives, usually of a high purity and different types of additives. DOWPER-C-S contains a water soluble detergent, a corrosion inhibitor, an anti-static compound, “hand agent” compounds, and a fatty acid scavenger.
Dry Cleaning PCE characterized by a high purity and different types of additives than associated with metal cleaning. For example, DOWPER-C-S contains a water soluble detergent, a corrosion inhibitor, an antistatic compound, “hand agent” compounds, and a fatty acid scavenger.
Metal Cleaning v. Dry Cleaning (b)
Surrogate Approach PCE from Sewers
Surfactants (a) amine alkylarenesulfonates (b) Sodium alkylarenesulfonates, (c) petroleum Sulfonates, (d) ethoxylated phenols and (e) ethoxylated phosphate esters. Use MBAS for presence/ absence as an inexpensive surrogate for detergents.
Generic Indicators (a) high TDS values, (b) presence of trihalomethanes, (c) microbiological, (d) soil gas (methane, etc).
Co-mingled PCE-Separate Sources
PCE from two sources chemically identical May be isotopically different Carbon and Chlorine stable isotope ratios 13C/12C and 37Cl/35Cl May differentiate sources prior to co-
mingling Effects of biodegradation need to be
considered Cl Cl
Cl CL
C C
-20.00
-22.00
-24.00
-26.00
-28.00
-30.00
-32.00
-34.00
-28.
00
-27.
00
-26.
00
-25.
00
-24.
00
-23.
00
-22.
00
-21.
00
-20.
00
TCE
PCE Source: Philp, P., 2003. Stable isotopes and biomarkers in Forensic chemistry. International Society of Environmental Forensics Workshop. May 19-20th, 2003. Stresa, Italy.
Isotopic Analysis for Source Discrimination
Use of C and Cl Isotopes to Differentiate PCE/TCE Sources
Degradation Rate Approach
Molar Ratio Approach
THANK YOU
