1

DRAFT REPORT

California’s Automobile Shredder Waste Initiative

Department of Toxic Substances Control

NOVEMBER 2002

(Photograph intentionally omitted)

Hazardous Waste Management Program

Statewide Compliance Division
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Acknowledgments

Under the direction of Mr. Watson Gin, P.E., Deputy Director, Hazardous Waste

Management Program, and Mr. Norman Riley, Chief, Statewide Compliance Division, the

report on California’s Automobile Shredder Waste Initiative was prepared by:

Mr. Peter J. Wood, Senior Hazardous Substances Scientist

Department of Toxic Substances Control

Hazardous Waste Management Program

Statewide Compliance Division

1001 I Street 11th Floor

Sacramento, CA 94814

The Department of Toxic Substances Control (DTSC) acknowledges the participation of

the following individuals for their contribution and assistance in the preparation of this

report.

Name Representing 

Abdul-Hamid Beig Department of Toxic Substances Control

Albert Fujitsubo Department of Toxic Substances Control

Claudia Nagy Department of Toxic Substances Control

Corey Yep Department of Toxic Substances Control

Ed Nieto Department of Toxic Substances Control

Larry Ramirez Department of Toxic Substances Control

Mellan Songco Department of Toxic Substances Control

Mike Shepard Department of Toxic Substances Control

Milad Iskander Department of Toxic Substances Control

Nancy Long Department of Toxic Substances Control

Pamela Shiro Department of Toxic Substances Control

Peggy J. Guichard-Watters Arizona Department of Environmental Quality

Peter Fuller State Water Resources Control Board

Ruth Williams-Morehead Department of Toxic Substances Control

Scott Walker California Integrated Waste Management Board

Steve Friesen Department of Toxic Substances Control

Tom Li Department of Toxic Substances Control

Xiaomei Ma Department of Toxic Substances Control

DTSC would also like to use this opportunity to acknowledge California’s automobile

shredder industry for the valuable information and assistance that they provided.
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Table of Contents

Page

Acknowledgments..............................................................................................................2

Table of Contents..............................................................................................................3

Tables and Figures.......................................................................................................... 5

Acronyms..........................................................................................................................6

Executive Summary..........................................................................................................7

Section 1:

The Regulation of Automobile Shredder Waste in California: A Summary......................9

I. Introduction.................................................................................................9

II. Background.................................................................................................10

Section 2:

California’s Automobile Shredder Waste Initiative...........................................................13

A. Introduction.................................................................................................13

B. Objectives...................................................................................................13

C. Site Surveys................................................................................................13

A. Results..................................................................................................14

B. Additional Observations........................................................................15

C. Conclusions..........................................................................................15

D. Sampling Investigation Methods and Design............................................17

A. Site Selection.......................................................................................17

B. Sample Collection and Analysis...........................................................17

C. Statistical Analysis of the Data............................................................17

E. Results......................................................................................................18

A. Total Concentrations of Lead...............................................................18

B. Total Concentrations of Copper...........................................................18

C. Total Concentrations of Zinc................................................................19

D. Soluble Concentrations of Lead...........................................................19

E. Soluble Concentrations of Cadmium....................................................19

F. Soluble Concentrations of Zinc............................................................19

G. Total Concentrations of PCBs.............................................................19

H. Federal Lead Concentrations..............................................................20

I. Federal Cadmium Concentrations.........................................................20

J. Total Semi-Volatile Organic Compounds..............................................20

F. Conclusions..............................................................................................21

G. Recommendations....................................................................................23

Appendix 1:

Shredder Waste Sampling and Analytical Protocol (April 2001)......................... 30
4

Appendix 2: Page

Untreated Shredder Waste - Summary of Total Lead, Copper

and Zinc Concentrations (mg/kg)........................................................................ 39

Appendix 3:

Untreated Shredder Waste - Summary of Soluble Lead, Cadmium

and Zinc Concentrations (mg/l)........................................................................... 40

Appendix 4:

Treated Shredder Waste - Summary of Total Lead, Copper

and Zinc Concentrations (mg/kg)........................................................................ 41

Appendix 5:

Treated Shredder Waste - Summary of Soluble Lead, Cadmium

and Zinc Concentrations (mg/l)........................................................................... 42

Appendix 6:

Summary of Total PCB Concentrations in Untreated and

Treated Shredder Waste.....................................................................................43

References..................................................................................................................... 44
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Tables and Figures

Section 1: Page

The Regulation of Automobile Shredder Waste in California: A Summary

Figure 1: Automobile Shredder Process, Products and Wastes........................... 5

Section 2:

California’s Automobile Shredder Waste Initiative

Table 1: State and Federal Regulatory Thresholds.............................................12

Table 2: Mean Total Concentration (mg/kg) and Calculated 90% Upper

Confidence Interval (mg/kg) for Lead, Copper, Zinc, and 

PCBs in Untreated and Treated Shredder Waste.....................................20

Table 3: Mean Soluble Concentration (mg/l) and Calculated 90% Upper

Confidence Interval (mg/l) for Lead, Cadmium, and Zinc in

Untreated and Treated Shredder Waste.................................................. 21

Table 4: Comparison of Total and Soluble Lead Concentrations in

Individual Samples of Untreated Shredder Waste................................... 22

Table 5: Comparison of Total and Soluble Cadmium Concentrations in 

Individual Samples of Untreated Shredder Waste................................... 23
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Definition of Acronyms and Abbreviations

ATS Alternative Technology Section

DHS Department of Health Services

DTSC Department of Toxic Substances Control

HWMP Hazardous Waste Management Program

mg/kg Milligrams per kilogram

mg/l Milligrams per liter

ND Not Detected

PCBs Polychlorinated biphenyls

PPE Personal protective equipment

PPM Parts per million

RCRA Resource Conservation and Recovery Act

RT Regulatory Threshold

SB Senate Bill

SCD Statewide Compliance Division

STLC Soluble Threshold Limit Concentration

SVOC Semi-Volatile Organic Compounds

TCLP Toxicity Characteristic Leaching Procedure

TTLC Total Threshold Limit Concentration

UCI Upper Confidence Interval

WET Waste Extraction Test

 
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Executive Summary

California’s Automobile Shredder Waste Initiative (Initiative) was financed with grant funds

provided by the United States Environmental Protection Agency through the Resource

Conservation and Recovery Act. The goals of the Initiative were three fold: evaluate the

adequacy of the Department of Toxic Substances Control’s (DTSC) automobile shredder

waste policy; affirm the regulatory status of the automobile shredders operating in

California; and ensure compliance by the automobile shredders with the existing statutes

and regulations.

In early 2000, DTSC initiated a comprehensive review of its past policies to ensure that the

policies conform to current laws and regulations, and are still valid considering current

scientific knowledge. One of the policies that came under review was Policy and

Procedure 88-6 entitled “Auto Shredder Waste Policy and Procedures” and addressing

DTSC’s regulation of both untreated and treated shredder waste. As part of reviewing the

subject policy and meeting the other goals of the Initiative, it was determined that on-site

surveys would provide the most up-to-date information regarding the current status of

California’s shredder industry. 

On-site surveys were conducted at each of the seven shredder facilities operating within

the State. Based on the results of the surveys, three facilities were selected for sampling

of both untreated and treated shredder waste. The analytical data characterizing a total of

70 samples collected at those facilities indicated that all samples of untreated shredder

waste exceeded the State regulatory thresholds for total lead (1,000 mg/kg), copper

(2,500 mg/kg) and zinc (5,000 mg/kg). The data also revealed that all samples of

untreated shredder waste exceeded the State regulatory thresholds for soluble lead (5.0

mg/l), cadmium (1.0 mg/l) and zinc (250 mg/l). Selected samples of untreated shredder

waste were also subjected to the federal Toxicity Characteristic Leaching Procedure

where less than one-third of those tested failed the federal regulatory thresholds for soluble

lead (5.0 mg/l) and cadmium (1.0 mg/l). The data also indicate that the treated shredder

waste from each facility exceeded the State regulatory thresholds for total lead and zinc. 

Furthermore, treated shredder waste from two facilities exceeded the State’s soluble

regulatory threshold for zinc, and treated shredder waste from one of the facilities

exceeded California’s soluble regulatory threshold for cadmium, thereby disqualifying the

treated wastes from classification as nonhazardous. Treated shredder waste which fails to

meet the conditions of its nonhazardous waste classification is subject to all applicable

hazardous waste management requirements including the payment of hazardous waste

generation fees. Although polychlorinated biphenyls were found in all samples collected,

only two samples exceeded the federal and State regulatory threshold of 50 mg/kg.
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Based on the results of the sampling investigation, it is recommended that DTSC:

C Rescind DTSC Policy and Procedure 88-6 entitled “Auto Shredder Waste Policy

and Procedures”; 

C Require facilities that wish to continue treating their shredder waste on-site to

obtain the appropriate authorization within a specified period of time; and

C Rescind all previously issued nonhazardous waste classifications for treated

shredder waste.
DHS’ Toxic Substances Control Division was the forerunner to the Department of Toxic Substances 1

Control.

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Section 1: The Regulation of Automobile Shredder Waste in California: A Summary

I. Introduction

The shredding of automobiles and major household appliances produces a waste 

consisting of primarily non-metallic materials that remain after the recyclable metals have

been removed. In California, the waste produced at metal shredding facilities large

enough to shred an automobile has been referred to as “automobile shredder waste” or,

more appropriately, “shredder waste” as these facilities shred a variety of recyclable

metals. Since 1984, shredder waste has been regulated as a non-Resource Conservation

and Recovery Act (RCRA) hazardous waste in California due to the presence of lead,

cadmium, copper, and zinc at levels above the State’s regulatory thresholds for those

metals. Shredder waste has been found to contain polychlorinated biphenyls (PCBs) at

concentrations which occasionally exceed the federal and State regulatory threshold of 50

ppm. Shredder waste is both a hazardous waste and a recyclable material subject to

California’s Hazardous Waste Control Law and the regulations that apply to hazardous

wastes. 

Between 1986 and 1992, California’s Department of Health Services (DHS) -Toxic

Substances Control Division - issued conditional nonhazardous waste classifications to 1

seven shredder facilities in California who successfully treated their shredder waste to

nonhazardous levels using similar metals fixation treatment technologies. DHS also

determined that if the treatment of shredder waste was “in-line” with the shredding

operation, authorization for hazardous waste treatment was not required. However, none

of the treatment technologies were capable of treating organic constituents such as PCBs,

or reducing total concentrations of the inorganic constituents present in shredder waste. 

Once the facility operator received a nonhazardous waste classification from DHS, the

treated shredder waste was no longer regulated as a hazardous waste. California’s

regulation of shredder waste and shredder facilities was formalized in the DHS Policy and

Procedure 88-6 in 1988.

In early 2001, DTSC began implementation of the Initiative to: evaluate the adequacy of the

Department of Toxic Substances Control’s (DTSC) automobile shredder waste policy;

affirm the regulatory status of the automobile shredders operating in California; and ensure

compliance by the automobile shredders with the existing statutes and regulations. Onsite surveys were conducted at each of the seven shredder facilities operating in the State. 

Based on the results of the surveys, three facilities were selected for sampling of both

untreated and treated shredder waste. The analytical data from those facilities indicated

that all samples of untreated shredder waste exceeded the State regulatory thresholds for
Environmental Liability Management, Inc. 1991. Beneficial Use of Automotive Shredder Residue in 2

Landfills. Prepared for the Recycling Research Foundation. 

10

total lead, copper and zinc. The data also showed that all samples of untreated shredder

waste exceeded the State regulatory thresholds for soluble lead, cadmium and zinc. 

Selected samples of untreated shredder waste were subjected to the federal Toxicity

Characteristic Leaching Procedure (TCLP) where a relatively small number failed the

regulatory threshold for soluble lead and cadmium. The data indicate that the treated

shredder waste from each facility also exceeded the State regulatory thresholds for total

lead and zinc. Furthermore, treated shredder waste from two facilities exceeded the

State’s soluble regulatory threshold for zinc, and treated shredder waste from one of the

facilities exceeded California’s soluble regulatory threshold for cadmium, thereby

disqualifying the wastes from classification as nonhazardous. Although PCBs were found

in all samples collected, only two samples exceeded the regulatory threshold.

The results of the Initiative provide DTSC with valuable information regarding new metal

separation methods now employed by California’s shredder industry to significantly

increase their ability to remove non-ferrous metals from shredder waste. Moreover, the

Initiative has also yielded information regarding the nature and amounts of shredder waste

currently being generated in California. However, it’s important to recognize that the

analytical data collected during the Initiative may not be representative of the remaining

four shredders currently operating within the State. 

II. Background

In the United States, approximately 10 to 12 million automobiles and about 40 million

appliances are recycled every year. DTSC estimates that approximately 700,000 2

automobiles and an unknown number of appliances are recycled by shredders in

California each year producing approximately 1.1 million tons of recyclable scrap metal

and 300,000 tons of waste. At the heart of the shredder is the hammermill which acts

much as a giant tree chipper by grinding the materials fed into it to fist-sized pieces (see

Figure 1.). The shredding of automobiles and household appliances results in a mixture of

ferrous metal (e.g. iron-containing scrap), nonferrous metal (e.g. non-iron-containing metal

alloys such as aluminum and copper), and shredder waste. These constituents are

separated by a variety of methods, generally on-site. Both the ferrous and non-ferrous

metals are sold to secondary smelters where they are recycled and used to manufacture

various metal products.

Shredder waste consists of glass, fiber, rubber, automobile fluids, dirt and plastics 

found in automobiles and household appliances that remain after the recyclable metals 

have been removed. Prior to 1984, shredder waste was not considered hazardous and

was either disposed or used as daily cover in municipal solid waste landfills.
Hammermill

Non-Ferrous Metal

Aggregate

Non-Ferrous Metal

Separation

Ferrous Metal

Separation

Product

80-90% Haz. Waste

10-20% Product

Product

Ferrous Metal

Shredder Waste

Treatment

Treated Shredder Waste

Figure 1.

+

Haz. Waste Non-Haz. Waste

Prepared By DTSC Nov. 2001

Letter Dated March 9, 1984, from DTSC to Dr. Kenneth Hekimian RE: Disposal of Automobile Shredder 3

Wastes from Hugo Neu-Proler and Clean Steel, Inc.

11

However, on March 9, 1984, DHS determined that shredder waste was a non-RCRA 3

hazardous waste because it typically and frequently exceeded regulatory thresholds for

several inorganic constituents. The then newly-established waste extraction test (WET)

revealed that shredder waste generally exceeded the soluble threshold limit concentrations

(STLCs) for lead, cadmium, and zinc. Additionally, it was found that shredder waste

exceeded the total threshold limit concentrations (TTLCs) for lead, copper and zinc. These

findings subjected shredder waste to statutory and regulatory requirements for hazardous

waste management, including permitting, transportation and disposal. Furthermore, it was

determined that shredder waste also exhibited the presence of PCBs at concentrations

which occasionally exceeded the federal and State regulatory threshold of 50 ppm. At that

time, the source of PCBs in shredder waste was unknown but appeared to be somehow

associated with major household appliances that are shredded together with automobiles

and other scrap for their metal content. The amount of shredder waste generated by

shredders prompted DHS to search for solutions to the permitting and disposal issues.
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In 1986, DHS’s Alternative Technology Section (ATS) began working with a shredder in

Los Angeles to determine if shredder waste could be treated so that it would qualify for a

nonhazardous waste classification pursuant to California Administrative Code section

66305(e) [predecessor to Title 22, California Code of Regulations (Cal. Code Regs.)

section 66260.200(f)]. ATS determined that if the treatment of shredder waste was “inline” with the shredding operation, a hazardous waste treatment variance or permit would

not be required. To qualify for this interpretation, the shredder was required to conduct a

final metals extraction step after treatment which, in most cases, consisted of a magnet

positioned above the end of a conveyor belt transporting the treated shredder waste to a

location where it could be consolidated into a waste pile. At that time, DHS did not have a

multi-tiered permitting program. Policy makers within DHS believed that allowing “in-line”

treatment without requiring a permit was the only viable solution. Although the various

metals fixation treatment technologies were successful in bringing the soluble inorganic

constituents below regulatory thresholds, the total inorganic contaminants (i.e. lead, copper

and zinc) were still present in the waste above the regulatory thresholds. ATS’ approach to

regulating treated shredder waste was later formalized in DHS Policy and Procedure 88-6.

Between 1986 and 1992, seven of the eight shredders operating in California applied for

and received nonhazardous waste classifications for treated shredder waste using

essentially the same treatment technology. The metals fixation treatment technology

employed by the shredders allowed the treated waste to pass the WET for all inorganic

constituents of concern, with the exception of lead.
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Section 2: California’s Automobile Shredder Waste Initiative

I. Introduction

In early 2000, DTSC’s Hazardous Waste Management Program (HWMP) initiated a

comprehensive review of its past policies to ensure that the policies conform to current

laws and regulations, and are still valid considering current scientific knowledge. One of

the policies that came under review was Policy and Procedure 88-6 entitled “Auto

Shredder Waste Policy and Procedures” and addressing DTSC’s regulation of both

untreated and treated shredder waste. As part of reviewing the subject policy, it was

determined that on-site surveys would provide the most up-to-date information regarding

the current status of the State’s shredder industry. 

II. Objectives

Between January 23 and February 20, 2001, staff from HWMP’s Statewide Compliance

Division (SCD) completed on-site surveys at each of the seven shredder facilities

operating in California. Based on the results of the survey, three shredder facilities were

selected for sampling investigations. The sampling investigations took place between May

14 and May 22, 2001. The objectives of both the surveys and subsequent sampling

investigations were to:

C Determine how California’s shredder industry has changed during the past 15

years;

C Determine how much shredder waste is being treated and disposed as nonhazardous; and

C Investigate the presence of lead, cadmium, copper, zinc and polychlorinated

biphenyls in samples of untreated and treated shredder waste.

III. Site Surveys

At the start of the Initiative, the number of active shredders operating in California was

unknown. DTSC staff therefore began by identifying whether previously known shredder

facilities were still active and whether any new shredders had been constructed during the

past 15 years. It was determined that there are currently seven shredder facilities

operating within the State. Two facilities are located in the San Francisco Bay area; one

facility is located in Central California; and four facilities are located in Southern California. 

One facility that was previously located in National City, near San Diego, was partially

dismantled and the hammermill was moved across the United States/Mexico border to

Mexicali, Mexico.
Baumgartner & Associates, Inc. 1992. Shredder Residue: Environmental Information and Characteristics 4

under RCRA. Prepared for the Recycling Research Foundation, Washington, DC.

14

Prior to surveying each shredder, DTSC conducted a file review to determine the

regulatory history and current status of each facility. In addition to the file review, DTSC

also examined hazardous waste manifest data to evaluate disposal trends. The file review

indicated that one facility had stored a significant amount of treated shredder waste onsite

since 1997. Furthermore, the hazardous waste manifest data revealed a major decline in

the amount of shredder waste transported off-site and possibly generated at several

facilities beginning in the mid-1990s. 

At the conclusion of the file reviews and the hazardous waste manifest data evaluation, onsite surveys were conducted at each facility to obtain up-to-date information on operational

activities. A questionnaire was developed and provided to each facility prior to the site

visit so that facility representatives would have an idea of the types of information DTSC

was interested in collecting. To minimize inconsistencies in the survey process, a single

individual was tasked with conducting each on-site survey and completing the

questionnaire for the facility.

A. Results

The surveys conducted by DTSC indicate that approximately 700,000 automobiles, an

unknown number of discarded major household appliances and other scrap metals are

currently being shredded each year in California, generating approximately 287,000 tons

of shredder waste. Automobiles represent roughly 47% of the shredder feedstock. The

remaining 57% comprise appliances and other steel-containing scrap. Furthermore,

research indicates that the composition of automobiles has changed during the past two

decades with the amount of plastics found in shredder waste increasing from

approximately 6% by weight in 1980 to about 12% by weight in 1990 . 

4

All shredders now use some form of written “Acceptance Policy” that is provided to scrap

dealers and identifies specific hazardous substances that will not be accepted if present in

the scrap metal received for shredding. Each shredder also employs radiation detection

devices at the facility’s weigh scale and workers that function as load checkers at various

locations throughout the facility to examine incoming loads of scrap metal and ensure that

all visibly detectable hazardous materials have been removed. Five shredders will only

accept scrap metals from automobile dismantlers and “feeder yards” that have been “preprepared” by having associated hazardous substances removed. Over 90% of the scrap

metals accepted by the remaining two facilities are also prepared off-site. All of the

hazardous substances removed from automobiles and scrap metals delivered to the

shredders are now being generated by off-site locations such as automobile dismantlers,

scrap metal recyclers and “feeder yards”.
Based on DTSC estimate in 1987. 5

15

The “Eddy Current” systems currently employed by all of the shredders have increased the

efficiency of the non-ferrous metals separation process from approximately 70% to 90%, 5

significantly reducing the amount of metals found in shredder waste. However, operational

limitations associated with using Eddy Current technology appear to have resulted in an

inability for most facilities to perform “in-line treatment” of the shredder waste and has led

to a multi-step metals separation and shredder waste treatment approach. Six shredders

currently store intermediate shredded material (also known as shredder aggregate)

consisting of approximately 80%-90% shredder waste and 10%-20% recoverable nonferrous metals for several days to weeks on-site until it is processed further. The amounts

of the shredder aggregate stored at the six facilities range from 100 - 2,000 tons. One

shredder is shipping intermediate shredded material to a second facility for further

processing without using either a hazardous waste manifest or registered hazardous

waste transporter.

Together, five shredders currently treat approximately 213,000 tons of shredder waste

each year, however, only one facility operates a true “in-line treatment” process pursuant to

Policy and Procedure 88-6. All five facilities are disposing of their treated shredder waste

in California: three facilities at Class III landfills; one facility at a Class II landfill; and one

facility at a monofill located at a former gypsum mine. The remaining two shredders are

disposing an estimated 74,000 tons of untreated shredder waste each year at municipal

waste landfills located in Arizona (57,000 tons) and Mexico (17,000 tons). One facility has

stored approximately 8,000 to 10,000 tons of treated shredder waste on-site since 1997.

 

B. Additional Observations

Historically, environmental contamination resulting from the operation of shredders has

been a concern. PCB contamination at one facility caused it to become listed as a State

Superfund site in 1991. The remedial action at the site resulted in the removal of

approximately 58,550 tons of PCB-contaminated shredder waste and soil and was

completed in March 1999. Characterization of the soil underlying the waste pile indicated

that the hazardous constituents found in shredder waste generally migrated to a depth of

18 inches below ground surface and were never found to exceed a depth of 30 inches. 

Currently, all of the shredder facilities have either completed, or are in the process of

paving their sites with concrete to reduce further soil contamination, provide a safer

environment for operating heavy equipment during the rainy season, and capture rainfall for

on-site reuse in the shredding operation.

C. Conclusions

It is estimated that approximately 300,000 fewer automobiles are shredded and 13,000

fewer tons of shredder waste are generated each year in California today as compared to

the mid-1980s. Automobiles now comprise 47% of the shredder feedstock as compared
 Based on DTSC estimate in 1987. 6

16

to an estimated 60% - 80% fifteen years ago. Although the overall amount of shredder 6

waste being generated is sightly less today, the amount of shredder waste generated per

automobile shredded appears to have risen. The proportional increase in the amount of

shredder waste generated today is probably due to increases in the amount of other scrap

metal shredded (e.g appliances, light gauge metal, etc.) and the expanded use of plastics

in newer automobiles. It is not known if the increased percentage of appliances and other

light gauge metals in the feedstock have altered the characteristics of the waste by

introducing previously unknown hazardous constituents.

All seven of the shredders currently operating within California have previously been issued

non-hazardous waste classifications for treated shredder waste. Five shredders are

treating a combined 213,000 tons of shredder waste each year in apparent compliance

with the requirements of their non-hazardous waste classifications. However, four out of

five shredders treating their shredder waste are not in compliance with the “in-line

treatment” provisions of DTSC Policy and Procedure 88-6. 

California’s shredder industry appears to have made significant progress during the past

decade toward removing hazardous materials from the scrap metals that they shred and

increasing the efficiency of their non-ferrous metal separation systems. Together, both

changes have the potential to reduce both the hazardous characteristics and amount of

shredder waste generated in the State. Sample analytical data provided by two facilities

characterizing untreated and treated shredder waste indicate compliance for all hazardous

constituents regulated under federal and State hazardous waste laws. However, in the

absence of data from samples collected and analyzed by DTSC, it is difficult to make

general statements regarding the hazardous characteristics of all shredder waste currently

generated in California. Furthermore, the management and disposal of hazardous

substances removed from automobiles and other scrap metals prior to shredding has

been transferred from the shredders to off-site locations such as automobile dismantlers,

scrap metal recyclers and “feeder yards”. California recently passed Senate Bill (SB) 633

to aid in reducing the use of mercury, a persistent bioaccumulative toxic metal, through

education and information. SB 633 requires DTSC to provide, to those businesses

engaged in the dismantling or crushing of motor vehicles, technical assistance regarding

the safe removal and proper disposal of mercury-containing light switches. 
17

IV. Sampling Investigation Methods and Design

A. Site Selection

A primary recommendation arising from the site surveys was the need to obtain samples

of untreated and treated shredder waste and analyze them for the presence of constituents

regulated under federal and State hazardous waste laws. Due to logistical and staffing

considerations, DTSC decided to conduct sampling investigations at two San Francisco

Bay area shredder facilities and one Central California shredder in May 2001. 

B. Sample Collection and Analysis

As previously indicated, the shredding of automobiles and major household appliances

results in a mixture of ferrous metal, nonferrous metal, and shredder waste. Untreated

shredder waste is a highly heterogeneous waste stream consisting of glass, fiber, rubber,

automobile fluids, dirt and plastics found in shredder feedstock that remain after the

recyclable metals have been removed. Shredder waste is generally screened prior to

treatment resulting in treated shredder waste exhibiting a particle size distribution <1.5"

making it more homogeneous in nature. The intermediate shredded material or “shredder

aggregate” (aggregate) represents a mixture of 80-90% shredder waste and 10-20%

nonferrous metal that is generated after the initial ferrous metal separation step of the

metal recycling process. Many shredders store aggregate on-site for a few days to

several weeks before processing it further to remove the nonferrous constituents from the

mixture. To address the goals of the Initiative, it was necessary to collect samples of

untreated shredder waste, aggregate and treated shredder waste. 

The heterogeneity and physical characteristics of shredder waste present a number of

challenges to sampling this waste stream. Although DHS had previously developed a

sampling and analytical protocol specific for shredder waste in 1987, DTSC determined

that an updated version was needed to meet the needs of the Initiative. Standard

procedures for collecting samples were developed using methods found in Arizona

Administrative Code, Title 18 (Environmental Quality), Chapter 13 (Department of

Environmental Quality), Article 13 (Special Waste), Section R18-13-307 (Best

Management Practices for Waste from Shredding Motor Vehicles) as a model. All

sampling and analytical procedures presented in DTSC’s revised sampling and analytical

protocol (Appendix 1) were designed to obtain representative samples for waste

characterization purposes and were consistent with the U. S. Environmental Protection

Agency’s “Test Methods for Evaluating Solid Waste, Physical/Chemical Methods”, 3rd

Edition (SW-846).

C. Statistical Analysis of the Data

In almost every instance, the sample variance for specific constituents of concern, 

characterizing samples of both untreated and treated waste collected from each facility,

exceeded the sample mean. In all instances where the variance exceeded the mean of a

sample population, the data were transformed via the arcsine transformation method

pursuant to SW-846 as required by State law. All subsequent statistical evaluations were
18

performed on the transformed scale and the calculated mean, standard deviation and 90%

upper confidence interval (UCI) were back-transformed in order to express this information

in the proper units of measure and complete the calculation for the appropriate number of

samples. 

V. Results

The results of the shredder waste sampling investigations provide valuable information

regarding California’s shredder industry. However, data characterizing samples of

untreated (including samples of aggregate) and treated shredder waste may not

necessarily reflect similar wastes generated by other shredders operating within the State. 

Table 1 presents the regulatory thresholds (RT) for the contaminants of concern.

Table 1.

State and Federal Regulatory Thresholds

Contaminant TTLC(mg/kg) STLC (mg/l) TCLP (mg/l)

Cadmium 100 1.0 1.0

Copper 2,500 25 N/A

Lead 1,000 5.0 5.0

PCBs 50 5.0 N/A

Zinc 5,000 250 N/A

A. Total Concentrations of Lead

Total concentrations of lead in untreated and treated shredder waste ranged between 900

mg/kg and 53,000 mg/kg. Table 2 reveals that in all cases, the 90% UCI exceeds the RT

for total lead in untreated and treated shredder waste. In all cases the calculated mean for

total lead in samples of untreated and treated shredder waste also exceed the RT for total

lead. 

B. Total Concentrations of Copper

Total concentrations of copper in untreated and treated shredder waste ranged between

433 mg/kg and 53,300 mg/kg. Table 2 reveals that in all but one case, the 90% UCI

exceeds the RT for total copper in untreated and treated shredder waste. In all but one

case, the calculated mean for total copper in samples of both untreated and treated

shredder waste also exceed the RT for total copper. However, additional samples need to

be collected (see Appendix 4) and analyzed before a definitive conclusion can be reached

regarding whether treated shredder waste at one facility exceeds the RT for total copper.
19

C. Total Concentrations of Zinc

Total concentrations of zinc in untreated and treated shredder waste ranged between 583

mg/kg and 19,300 mg/kg. Table 2 reveals that in all cases, the 90% UCI exceeds the RT

for total zinc in untreated and treated shredder waste. In all cases the calculated mean for

total zinc in samples of untreated and treated shredder waste also exceed the RT for total

zinc.

D. Soluble Concentrations of Lead

Soluble concentrations of lead in untreated shredder waste ranged between 56.4 mg/l and

342 mg/l while soluble concentrations of lead in treated shredder waste ranged between

0.25 mg/l and 68.3 mg/l. Table 3 indicates that in every case the 90% UCI exceeded the

RT for soluble lead in untreated and treated shredder waste. However, in all cases the

90% UCI for soluble lead in treated shredder waste was well below the 50 mg/l limit for

soluble lead required for the issuance of nonhazardous waste classifications for treated

shredder waste. In every case the calculated mean for soluble lead in untreated shredder

waste exceeded 50 mg/l.

The calculated appropriate number of samples for Facility B (see Appendix 5) exceeds the

actual number of samples collected with respect to soluble lead concentrations. Therefore,

additional samples need to be collected and analyzed before a definitive conclusion can

be reached regarding whether treated shredder waste at Facility B exceeds the RT for

soluble lead.

E. Soluble Concentrations of Cadmium

Soluble concentrations of cadmium in untreated shredder waste sampled ranged between

0.66 mg/l and 5.37 mg/l while soluble concentrations of cadmium in treated shredder

waste ranged between 0.13 mg/l and 2.15 mg/l. Table 3 demonstrates that both the 90%

UCI and calculated mean for untreated shredder waste from each facility exceed the RT for

soluble cadmium. However, Table 2 also demonstrates that in only one case did the 90%

UCI and calculated mean exceed the RT for soluble cadmium in treated shredder waste.

F. Soluble Concentrations of Zinc

Soluble concentrations of zinc in untreated shredder waste ranged between 325 mg/l and

1,280 mg/l while soluble concentrations of zinc in treated shredder waste ranged between

1.34 mg/l and 1,150 mg/l. Table 3 reveals that both the 90% UCI and calculated mean for

untreated shredder waste exceed the RT for soluble zinc. However, Table 2 also indicates

that in only one case was the 90% UCI and calculated mean below the RT for soluble zinc

in treated shredder waste.

G. Total Concentrations of PCBs

Total concentrations of PCBs in untreated shredder waste sampled ranged between 0.59

mg/kg and 129 mg/kg while total concentrations of PCBs in treated shredder waste

ranged between 2.57 mg/kg and 45.1 mg/kg. Table 2 reveals that in no case did either the
20

90% UCI or the calculated mean for untreated and treated shredder waste exceed the RT. 

H. Federal Lead Concentrations

Thirteen samples were selected to be analyzed for soluble lead and cadmium using the

federal Toxicity Characteristic Leaching Procedure (TCLP) method. Several samples

exhibiting both high total and soluble (as determined by the Waste Extraction Test) lead

and cadmium concentrations were selected for TCLP analysis. 

Table 4 indicates that soluble lead concentrations as measured by TCLP ranged between

0.51 mg/l and 24.6 mg/l. Five of the thirteen samples analyzed using TCLP were found to

exceed the federal RT for lead of 5.0 mg/l.

I. Federal Cadmium Concentrations

Table 5 demonstrates that soluble cadmium concentrations as measured by TCLP ranged

between Not Detected and 1.17 mg/l. Only two of the twelve samples analyzed using

TCLP were found to exceed the federal RT for cadmium of 1.0 mg/l. 

J. Total Semi-Volatile Organic Compounds (SVOC)

Two samples from each facility were selected for SVOC analysis. The data indicated the

presence of phthalates in five of the six samples analyzed for SVOCs. Naphthalene was

detected in one sample. 
 Based on DTSC estimates in 1987. 7

21

VI. Conclusions

C Approximately 700,000 automobiles, an unknown number of major household

appliances, and other scrap metal are currently being shredded in California each

year generating an estimated 287,000 tons of shredder waste. These totals reflect

a decrease of 300,000 automobiles shredded and 13,000 tons of shredder waste 7

annualy generated within the State today as compared to the mid-1980s.

C Although all seven shredders currently operating in California have been issued

nonhazardous waste classifications for their treated shredder waste, two facilities

are not currently treating their shredder waste. Five shredders treat a combined

213,000 tons of shredder waste each year which is all disposed in California as

nonhazardous waste. The remaining two facilities are disposing 74,000 tons of

untreated shredder waste at landfills in Arizona (57,000 tons) and Mexico (17,000

tons). 

C The majority of shredders operating in California are in violation of in-line treatment

provisions of DTSC’s auto shredder policy and procedure. Four of the five

shredders that treat their shredder waste are not in compliance with the “in-line

treatment” provisions of the policy and procedure. Two shredders are engaged in

illegally transporting and accepting aggregate, and one of these facilities has also

stored between 8,000 and 10,000 tons of treated shredder waste on-site since

1997. 

C The analytical data from the three facilities selected for sampling indicate that all

samples of untreated shredder waste (including all samples of aggregate obtained

at one facility) exceeded the State RTs for total lead, copper and zinc. Furthermore,

analytical data characterizing all samples of untreated shredder waste and

aggregate exceeded the State RTs for soluble lead, cadmium and zinc. Selected

samples of untreated shredder waste and aggregate were analyzed by the federal

TCLP test method where less than one-third failed the RT for soluble lead and

cadmium.

C The data also indicate that the treated shredder waste from each facility also

exceeded the State RTs for total lead and zinc. Samples of treated shredder waste

from two facilities also exceeded the California RT for total copper. Furthermore,

treated shredder waste from two facilities exceeded the State’s soluble RT for zinc,

and one of the facilities also exceeded California’s soluble RT for cadmium, thereby

disqualifying those wastes from classification as nonhazardous.
Baumgartner & Associates, Inc. 1992. Shredder Residue: Environmental Information and Characteristics 8

under RCRA. Prepared for the Recycling Research Foundation, Washington, DC.

22

C Although PCBs were found in all samples collected, only two samples exceeded the

regulatory threshold. Additional testing for SVOCs indicated the presence of

phthalates in five of the six samples analyzed, and naphthalene was detected in one

sample. The presence of phthalates is not unexpected as they are commonly used 8

in the manufacture of plastics found in automobiles and other products such as

major household appliances.

C A comparison of data characterizing untreated shredder waste generated in 1986

with recently acquired samples of untreated shredder waste indicate a downward

trend in the total concentration of PCBs. This finding is probably the result of

increased efficiency in the removal of PCB-containing capacitors from appliances

prior to shredding. However, the data also demonstrate an upward trend in the total

concentration of lead and the soluble concentration of cadmium. The increased

concentrations of these metals in shredder waste may be the result of shredding

increased amounts of major household appliances which contain a higher

percentage of galvanized steel as compared to automobiles. The galvanization

process uses zinc to coat steel for corrosion protection and zinc normally contains

trace amounts of lead and cadmium. It is possible that the increased levels of these

metals in shredder waste is the result of the zinc layer being removed during

shredding. 
23

VII. Recommendations

Based on the results of the on-site surveys and sampling investigations, DTSC has

evaluated a number of options in order to develop recommendations that address the

following goals of the Initiative:

A. Evaluate the adequacy of DTSC’s automobile shredder waste policy; and

B. Ensure compliance with the existing statutes and regulations.

A. Evaluate the adequacy of DTSC’s automobile shredder waste policy. 

The options concerning the adequacy of DTSC Policy and Procedure 88-6 include:

1. Status quo

2. Revise DTSC Policy and Procedure 88-6

3. Rescind DTSC Policy and Procedure 88-6

1. Status Quo

Pros:

C Has no impacts to the existing regulatory structure.

C Does not require the expenditure of additional resources by either DTSC or

California’s automobile shredder industry.

C Continues to allow the disposal of treated shredder waste in Class III landfills. 

Cons:

C Allows California’s automobile shredder industry to continue on-site treatment of

shredder waste without authorization.

C Continues a policy whereby California’s automobile shredder industry does not pay

hazardous waste generator fees for shredder waste that is treated. 

2. Revise DTSC Policy and Procedure 88-6

Pros:

C Allows DTSC to update its regulation of California’s automobile shredder industry

by identifying the appropriate regulatory structure for automobile shredders treating

their shredder waste.

Cons:

C On-site treatment authorization options that currently exist may not adequately

address the needs of California’s automobile shredder industry. 
24

3. Rescind DTSC Policy and Procedure 88-6

Pros:

C Removes a DTSC policy and procedure that is inconsistent with current California

law.

Cons:

C May create confusion within California’s automobile shredder industry regarding the

continued treatment of shredder waste and the regulation of their facilities by

DTSC.

Recommendation: Option 3. Rescind DTSC Policy and Procedure 88-6 entitled “Auto

Shredder Waste Policy and Procedures.” 

B. Ensure compliance with the existing statutes and regulations.

The options for DTSC to regulate California’s auto shredder industry pursuant to existing

statutes and regulations include:

1. Status quo

2. Require facilities that wish to continue treating their shredder waste on-site to 

obtain the appropriate authorization within a specified period of time

3. Rescind all previously issued nonhazardous waste classifications for treated 

 shredder waste 

1. Status Quo

Pros:

C Has no impacts to the existing regulatory structure.

C Does not require the expenditure of additional resources by either DTSC or

California’s automobile shredder industry.

C California’s automobile shredders are not required to alter their operational

activities. 

C Requires no change in DTSC’s regulation of California’s automobile shredder

industry.

Cons:

C Is inconsistent with DTSC’s regulatory responsibility to enforce California’s

hazardous waste laws and regulations. 

2. Require facilities that wish to continue treating their shredder waste on-site to 

obtain the appropriate authorization within a specified period of time
25

Pros:

C Consistent with DTSC’s regulatory responsibility to enforce California’s hazardous

waste laws and regulations.

Cons:

C Compliance with existing on-site treatment authorization requirements may result in

many shredders ceasing their shredder waste treatment activities. 

C May increase the amount of untreated shredder waste disposed in neighboring

States.

3. Rescind all previously issued nonhazardous waste classifications for treated shredder

waste

Pros:

C Allows DTSC to re-evaluate the efficacy of shredder waste treatment processes. 

Cons:

C Effectively prohibits the disposal of treated shredder waste in Class III landfills within

California.

C Eliminates any incentive for California’s automobile shredder industry to treat

shredder waste.

C Will result in higher waste disposal costs for California’s automobile shredder

industry.

C Will increase the amount of untreated waste disposed in neighboring States.

 

Recommendation(s): Options 2 and 3. Require facilities that wish to continue treating their

shredder waste on-site to obtain the appropriate authorization within a specified period of

time; and rescind all previously issued nonhazardous waste classifications for treated

shredder waste.
26

TABLE 2.

Mean Total Concentration (mg/kg)

Untreated and Treated Shredder Waste

Facility (waste type) Lead Copper Zinc PCBs

A (Untreated) 1,739 2,170 11,850 14.0

A (Treated) 2,202 1,933 6,685 4.89

B (Untreated) 4,508 9,727 9,727 7.03

B (Treated) 1,653 4,346 5,806 8.91

C (Aggregate) 3,020 4,462 11,150 28.0

C (Treated) 2,026 1,343 8,089 22.7

Regulatory Threshold 1,000 2,500 5,000 50

Calculated 90% Upper Confidence Interval (mg/kg)

Untreated and Treated Shredder Waste

Facility (waste type) Lead Copper Zinc PCBs

A (Untreated) 1,842 3,116 12,460 16.0

A (Treated) 2,403 3,155 7,385 5.46

B (Untreated) 7,841 14,270 11,590 10.7

B (Treated) 2,058 9,353 8,182 13.7

C (Aggregate) 3,642 8,214 12,350 42.4

C (Treated) 2,285 1,887 9,320 27.6

Regulatory Threshold 1,000 2,500 5,000 50
27

TABLE 3.

Mean Soluble Concentration (mg/l)

Untreated and Treated Shredder Waste

Facility (waste type) Lead Cadmium Zinc

A (Untreated) 77.7 3.05 911

A (Treated) 29.3 1.56 439

B (Untreated) 162 1.47 572

B (Treated) 4.39 0.33 33.8

C (Aggregate) 110 2.19 829

C (Treated) 18.9 N/A 304

Regulatory Threshold 5.0 1.0 250

Calculated 90% Upper Confidence Interval (mg/l)

Untreated and Treated Shredder Waste

Facility (waste type) Lead Cadmium Zinc

A (Untreated) 84.9 3.34 965

A (Treated) 33.6 1.72 491

B (Untreated) 153 1.68 676

B (Treated) 10.3 0.58 132

C (Aggregate) 121 2.40 900

C (Treated) 26.9 N/A 327

Regulatory Threshold 5.0 1.0 250
28

TABLE 4.

Comparison of Total & Soluble Lead Concentrations in Individual Samples

Untreated Shredder Waste

Sample (Regulatory Threshold = 1,000 Waste Extraction Test (WET) Toxicity Characteristic Leaching Procedure

Location mg/kg) (Regulatory Threshold = 5.0 mg/l) (TCLP)

Total Concentration (mg/kg) Soluble Concentration (mg/l) Soluble Concentration (mg/l)

(Regulatory Threshold = 5.0 mg/l)

Facility A 1,700 68.6 3.56

Facility A 1,590 71.4 5.90

Facility B 6,640 90.8 *6.46/3.57

Facility B 3,220 342 7.91

Facility B 2,570 118 5.24

Facility B 2,970 163 4.34

Facility B 3,260 179 1.92

Facility B 53,400 287 24.6

Facility C 3,600 95.1 2.28

Facility C 2,520 106 1.42

Facility C 2,080 97.5 0.51

Facility C 5,640 137 1.04

Facility C 5,240 150 3.85

* Sample tested twice
29

TABLE 5.

Comparison of Total & Soluble Cadmium Concentrations in Individual Samples

Untreated Shredder Waste

Sample Total Concentration (mg/kg) Soluble Concentration (mg/l) Soluble Concentration (mg/l)

Location (Regulatory Threshold = 100 Waste Extraction Test (WET) Toxicity Characteristic Leaching Procedure

mg/kg) (Regulatory Threshold = 1.0 (TCLP)

mg/l) (Regulatory Threshold = 1.0 mg/l)

Facility A 45.0 5.37 1.04

Facility A 33.2 2.10 1.17

Facility B 35.7 1.05 0.17

Facility B 126 2.01 0.17

Facility B 123 1.38 0.17

Facility B 42.6 2.24 0.36

Facility B 49.5 1.97 0.34

Facility C 33.3 2.88 0.37

Facility C 32.3 1.94 0.37

Facility C 30.9 2.33 0.43

Facility C Not Detected Not Tested 0.37

Facility C Not Detected Not Tested 0.36
 Except in those situations where only on-line generated shredder waste is being sampled and the 9

activities of the third and fourth team members are combined.

30

Appendix 1.

Shredder Waste

Sampling and Analytical Protocol

(April 2001)

VIII. Background

The shredding of automobiles results in a mixture of ferrous metal (e.g. iron

containing scrap), nonferrous metal (e.g. non-iron containing metal alloys), and 

shredder waste. Untreated shredder waste is a highly heterogeneous waste

stream consisting of glass, fiber, rubber, automobile fluids, dirt and plastics found in

automobiles that remain after the recyclable metals have been removed. Treated

shredder waste is generally screened prior to treatment resulting in a particle size

distribution < 1.5" and is more homogeneous in nature. Automobile “shredder

aggregate” (aggregate) represents a mixture of 80%-90% shredder waste and

10%-20% nonferrous metal that is generated after the initial ferrous metal

separation step of the metal recycling process. Many shredders store aggregate

on-site for a few days to several weeks before processing it further to remove the

nonferrous constituents from the mixture. 

IX. Purpose of Sampling and Analytical Protocol

The heterogeneity and physical characteristics of shredder waste present a number

of challenges to sampling this waste stream. All sampling procedures presented in

this sampling and analytical protocol are designed to obtain representative

samples for waste characterization purposes and are consistent with the U. S.

Environmental Protection Agency’s “Test Methods for Evaluating Solid Waste,

Physical/Chemical Methods”, 3 Edition. rd

III. Sampling Team

The sampling team will be comprised of four (4) field certified, Department of Toxic 9

Substances Control (DTSC) staff. A DTSC Industrial Hygienist will provide

additional technical support as needed and may be present during the sampling

event. Two team members will be responsible for sample collection, packaging

and shipping. A third team member will be responsible for processing necessary

paperwork, completing Chain-of-Custody forms, maintaining a field log, and

labeling containers for waste pile sampling. The fourth team member will be the
31

designated “Team Leader” and will be responsible for coordinating with facility

personnel, getting help in case of an emergency and performing other support

tasks. Where appropriate, facility personnel may be asked to collect a sample in

the presence of the sampling team. 

 

IV. Sampling Protocol

A. On-line Generated Waste

1. Untreated Waste - As the untreated shredder waste is generated,

one 500-gram sample will be collected every thirty (30) minutes over

a three hundred (300) minute time frame while the facility is in

operation generating ten (10) discreet composite samples. Care

should be taken to collect samples that reflect the particle size

distribution of the waste being generated. Two (2) duplicate samples

will also be collected for a total of twelve (12) samples.

2. Treated Waste - When the average amount of treated shredder waste

generated from one-half to a full day’s operation has fully cured

(approximately 3 days after treatment), the appropriate waste pile

sampling protocol from Section C. below will be selected to obtain

samples.

B. Aggregate

1. On-line Generated - As the aggregate is generated, one 500-gram

sample will be collected every thirty (30) minutes over a three hundred

(300) minute time frame while the facility is in operation generating

ten (10) discreet composite samples. Care should be taken to collect

samples that reflect the particle size distribution of the aggregate

being generated. Two (2) duplicate samples will also be collected for

a total of twelve (12) samples.

2. Stored Piles - The average amount of aggregate generated from

one-half to a full day’s operation must be formed into a square for

sampling purposes. One 2,000-gram sample will be collected from

each sample point as indicated in Exhibit 1. Samples from sample

points A-1, B-1, and C-1 will be collected from the top of the pile. 

Samples from sample points A-2, B-2, and C-2 will be collected from

the base of the pile. A sample from point C-3 will be collected at the

vertical midpoint at the center of the pile. The seven (7) samples will

be numbered consecutively. Three (3) of the 2,000-gram samples will

the be chosen at random by selecting numbers from a table of
32

random numbers or a calculator programmed to generate random

numbers. Two (2) duplicate samples will also be collected for a total

of five (5) samples. 

C. Waste Piles

1. Small Waste Pile (< 1,000 tons) - If possible, the waste pile should be

formed into a square for sampling purposes. One 2,000-gram (500-

gram for treated shredder waste) sample will be collected from each

sample point as indicated in Exhibit 1. Samples from sample points

A-1, B-1, and C-1 will be collected from the top of the pile. Samples

from sample points A-2, B-2, and C-2 will be collected from the base

of the pile. A sample from point C-3 will be collected at the vertical

midpoint at the center of the pile. The seven (7) samples will be

numbered consecutively. Three (3) of the 2,000-gram samples will

the be chosen at random by selecting numbers from a table of

random numbers or a calculator programmed to generate random

numbers. Two (2) duplicate samples will also be collected for a total

of five (5) samples. 

2. Medium Waste Pile (1,000 to 2,500 tons) - If possible, the waste pile

should be formed into a square for sampling purposes. One 2,000-

gram (500-gram for treated shredder waste) sample will be collected

from each sample point as indicated in Exhibit 1. Samples from

sample points A-1, B-1, and C-1 will be collected from the top of the

pile. Samples from sample points A-2, B-2, and C-2 will be collected

from the base of the pile. A sample from point C-3 will be collected at

the vertical midpoint at the center of the pile. Seven (7) samples will

be collected in the manner described above plus two (2) duplicate

samples for a total of nine (9) samples.

3. Large Waste Pile (>2,500 tons) - If possible, the waste pile should be

formed into a square for sampling purposes. One 2,000-gram

sample will be collected from each sample point as indicated in

Exhibit 2. Samples from sample points A-1, B-1, and C-1 will be

collected from the top of the pile. Samples from sample points A-3,

B-3, and C-3 will be collected from the base of the pile. Samples A2, B-2, and C-2 will be collected at the vertical midpoint of each

diagonal. Sampling points D-1, D-2, and D-3 will be selected at the

discretion of the sampling team leader. Twelve samples will be

collected in the manner described above plus two (2) duplicates for a

total of fourteen (14) samples. 
33

V. Field Quality Assurance/Quality Control

In addition to the samples collected from the designated sampling points, two

duplicate samples will also be gathered during each sampling investigation. These

duplicates can be collected from any of the sample locations at the same time as

the corresponding “original” sample. The duplicate samples will be given a sample

identification number different from the “original” so that laboratory personnel will not

know the identity of the duplicates. The duplicate samples will be noted in the field

notebook and will also be cross-referenced in the report of analysis which will follow

the sampling event. 

VI. Sampling Methodology

A. Equipment

Due to the physical nature of the shredder waste, conventional waste pile

sampling equipment would not be expected to perform adequately for larger

waste piles. The equipment of choice for these efforts should consist of a

blade-equipped front-end loader, backhoe (e.g. Caterpillar 215), or dozer so

the pile can be placed into the proper configuration prior to sampling and

properly accessed during sampling. 

The waste pile should be prepared for sampling by using heavy equipment

to form it into a square of approximately uniform height. Depending on the

size of the waste pile, Exhibit 1 or Exhibit 2 can be used to identify evenly

distributed sampling locations. The collection of samples from the pile’s

center is accomplished by creating one or more trenches so that a middle

sampling point for a specific diagonal passes through the trench. 

B. Decontamination

All sampling equipment is to be decontaminated prior to the processing of

each sample. If a shovel, trowel or other type of sampling device is used to

collect a sample, it must be decontaminated between each sample location.

C. Sample Retrieval, Containers and Preservation

Care should be taken to collect samples that reflect the particle size

distribution of the waste being generated. Samples may be collected by

selecting a number of sub-samples from each sample location until a total of

either five (5) hundred grams or two (2) thousand grams of material has

been obtained. Samples should be collected in one quart glass wide mouth

I-CHEM jars (or equivalent) for five (5) hundred gram samples or one gallon
34

glass wide mouth I-CHEM jars (or equivalent) for two (2) thousand gram

samples. These are laboratory prepared and contain a Teflon liner within a

plastic screw cap. The jars should be filled to the top. Glove covers used by

the sampler will be replaced between each sample. All sample jars must be

identified on a Chain-of-Custody form. 

D. Documentation of Chain-of-Custody

All samples will be labeled and sealed upon collection. The sample number,

date, time of collection, location, and signature of the sampler will be

recorded. In addition, the samples will be entered on Chain-of-Custody

forms before delivery to the laboratory. Log book entries for each sample will

include as a minimum:

C Location of sampling point

C Sample numbers

C Date and time

C Field observations

C Samplers’ signature(s)

C Photograph log

C Analyses to be done 

 VII. Analytical Protocol

A. Scope and Application

1. This procedure describes the preparation and analysis of shredder

waste to determine the presence of metals and polychlorinated

biphenyls (PCBs) for waste classification purposes. Other related

samples may also be amenable to these procedures, but the

reliability of the method should be established before analysis of

samples for the purposes of waste classification. Other analyses

may be done on samples prepared by these procedures, but

appropriate sample handling and preservation procedures should be

followed.

2. This method is recommended for use only by, or under the close

supervision of, analysts experienced in hazardous waste preparation

and analysis. Analysis done for the purpose of waste classification

must be done in a California certified hazardous waste testing

laboratory.

3. The details of analytical procedures can be found in the

corresponding references. The sensitivity of this method for PCBs is
35

approximately 1 mg/kg. The sensitivity of the method for metals

depends primarily on the choice of analytical techniques, but in no

case should the detection limits exceed the corresponding Soluble

Threshold Limit Concentrations (STLCs) listed in Article 11, Title 22

of the California Code of Regulations.

B. Safety

Unless the samples are known to be free of volatile substances, all samples

should be handled in a well functioning hood. If some sample handling

cannot be done in a hood, personal protection should be consistent with the

field sampling safety plan.

C. Apparatus and Materials

1. Sieves, polyethylene or stainless steel, No. 10 (2 mm opening) and

other sizes as required by the option used.

2. Mill, mechanical. The mill must be demonstrated to not contaminate

samples. This can be demonstrated by a combination of (i) Analysis

of equipment blanks (e.g. , wipes with hexane-soaked filter paper for

PCB analysis, and wipes with de-ionized water-soaked filter paper

for metal analysis; (ii) Analysis of method blanks (e.g. milling material

known to be free of contamination prior to and after grinding

samples). A variety of mills may be used, although machines with a

cutting action may be more successful than grinders for samples

containing significant amounts of rubber or plastic. Freezing samples

with liquid nitrogen prior to grinding may improve the effectiveness of

the mill.

D. Sample Handling and Preservation

Samples must be collected in accordance with procedures approved by

DTSC (see Section IV.). No sample preservation is required for PCBs or

metals in shredder waste. 

E. Procedures

Prepare samples according to either of the two options below. Other

procedures must be approved by DTSC. A minimum size sample of 10

grams is to be analyzed according to the procedures listed in Table 1.
36

1. Option A - Procedure for the preparation of shredder waste prior to

analysis for total metals and the Waste Extraction Test: The

representative composite sample is mixed throughly then reduced by

coning and quartering, or an equivalent method, to yield a sub-sample

which can be easily managed (ca. 500 grams). The sample shall be

passed directly, or shall be milled to pass, through a No. 10 (2 mm)

standard sieve before it is analyzed. If the sample contains nonfriable solid particles which do not pass directly through a No. 10

sieve and which are extraneous to the waste or other material, they

shall be removed to the extent feasible by mechanical means and

discarded. The following are examples of these extraneous particles

that shall be removed and discarded:

a. Non-friable metal fragments

b. Rocks, pebbles and plant debris 

Solids which remain after removal of these extraneous materials shall

be milled to pass through the No. 10 sieve and shall be combined

and mixed well with the solids which passed through the sieve without

milling. The combined solids shall be analyzed or extracted as

prescribed.

2. Option B - If prior analysis has demonstrated that there is no

significant difference in the contaminant concentrations in the various

size fractions for a particular waste, then the grinding of samples may

be omitted and the analysis may be done on the fraction passing

through a No. 10 (2 mm) sieve. The demonstration of homogeneity

must include at least four (4) samples separated into four (4)

fractions, using No. 2, No. 4 and No. 10 sieves. The results must be

evaluated using a t-Test or other statistical test.

F. Quality Control (QC)

A minimum of 10% of the samples are to be analyzed in duplicate. For

highly heterogeneous samples, triplicate samples should be analyzed. All

QC requirements of the certification program and the referenced analytical

methods must be followed. The final report will include results for field

replicates, lab replicates, lab method blanks, lab spikes, and lab QC

samples, if used.
37

VIII. Health and Safety

Adherence by the sampling team to the following activities will ensure proper health

and safety in the field:

• Proper training of the sampling team;

• Coordination with a DTSC Industrial Hygienist in assessing any potential

hazards prior to the site visit;

• Use of proper personal protective equipment (PPE); and

• Designating a team member to be responsible for getting help in case of an

emergency situation. 

PPE used by the sampling team should include: hard hat, Tyvek suit, air purifying

respirator (APR), extra cartridges for the respirator, eye protection, steel toed

boots, nitrile gloves, hearing protection, and a first aid kit.

Prior to each sampling investigation, a DTSC Hazard Appraisal and Recognition

Plan (HARP) Pre-Site Visit form will be completed and approved by a DTSC

Industrial Hygienist. The HARP form identifies potential health hazards posed at

each facility to be sampled, the PPE to be used, and the location of the nearest

hospital. 

Table 1 - Analytical Methods

Test Category Method Number

Cadmium* 6010, 7130, 7131

Chromium, Total* 6010, 7190, 7191

Copper 6010, 7210, 7211

Lead* 6010, 7420, 7421

Mercury* 7470, 7471

Nickel 6010, 7520, 7521

Zinc 6010, 7950, 7951

PCBs 8080, 8081, 8082

* U.S. EPA Method 1311 (Toxicity Characteristic Leaching Procedure). 

Note: A modified Method 6010 using ICP/MS is acceptable as equivalent to Method

6010. Methods are from SW-846, Test Methods for Evaluating Solid Waste,

Physical/Chemical Methods”, 3 Edition. rd
Exhibit 1

Selection of Sample Points for Small and Medium Waste Piles

A2

A1

B2

B1

C1 C3 C2

Hole or Trench

C1

C2

A1 B1

A2

B2

C3

Auto Shredder Waste Pile

(Top)

(Top)

(Top)

Exhibit 2

Selection of Sample Points for Large Waste Piles

A3

A1

B3

B1

C1 C3

Trench

1

3

Auto Shredder Waste Pile

A2

B2 C2

D1

D2

D3

(Top)

(Top)

(Top)

(Top)

(Base)

38

 

 
39

Appendix 2.

UNTREATED SHREDDER WASTE

Summary of Total Lead Concentrations (mg/kg)

(Regulatory Threshold = 1,000 mg/kg)

Location Mean Standard 90% Upper Median Minimum Maximum Number of Appropriate

Deviation Confidence Samples Number of

Interval Samples

Facility A 1,739 11.8 1,842 1,700 1,250 2,270 14 <1

Facility B 4,508 2,940 7,841 3,095 900 53,400 12 1

Facility C 3,020 137 3,642 2,520 2,070 5,640 9 <1

Summary of Total Copper Concentrations (mg/kg)

(Regulatory Threshold = 2,500 mg/kg)

Location Mean Standard 90% Upper Median Minimum Maximum Number of Appropriate

Deviation Confidence Samples Number of

Interval Samples

Facility A 2,170 658 3,116 1,415 594 13,500 14 7

Facility B 9,727 2,810 14,27 5,400 1,309 42,000 12 <1

Facility C 4,462 2,630 8,214 2,720 492 27,500 9 4

Summary of Total Zinc Concentrations (mg/kg)

(Regulatory Threshold = 5,000 mg/kg)

Location Mean Standard 90% Upper Median Minimum Maximum Number of Appropriate

Deviation Confidence Samples Number of

Interval Samples

Facility A 11,852 61.9 12,464 11,600 8,530 14,000 14 <1

Facility B 9,727 531 11,589 8,855 3,030 16,800 12 <1

Facility C 11,145 140 12,348 10,600 9,310 17,000 9 <1
40

Appendix 3.

UNTREATED SHREDDER WASTE

Summary of Soluble Lead Concentrations (mg/l)

(Regulatory Threshold = 5.0 mg/l)

Location Mean Standard 90% Upper Median Minimum Maximum Number of Appropriate Number

Deviation Confidence Samples of Samples

Interval 

Facility A 77.7 1.28 84.9 76.4 54.6 141 14 <1

Facility B 162 10.1 153 143 86.4 342 12 <1

Facility C 110 1.24 121 106 72.0 150 9 <1

Summary of Soluble Cadmium Concentrations (mg/l)

(Regulatory Threshold = 1.0 mg/l)

Location Mean Standard 90% Upper Median Minimum Maximum Number of Appropriate Number

Deviation Confidence Samples of Samples

Interval 

Facility A 3.05 0.78 3.34 2.94 2.10 5.37 14 <1

Facility B 1.47 0.54 1.68 1.55 0.66 2.24 10 3

Facility C 2.19 0.37 2.40 2.07 1.86 2.88 6 <1

Summary of Soluble Zinc Concentrations (mg/l)

(Regulatory Threshold = 250 mg/l)

Location Mean Standard 90% Upper Median Minimum Maximum Number of Appropriate Number

Deviation Confidence Samples of Samples

Interval 

Facility A 911 5.97 965 922 671 1,120 14 <1

Facility B 572 27.4 676 501 325 1,280 12 <1

Facility C 829 7.41 900 880 529 1,010 9 <1
41

Appendix 4.

TREATED SHREDDER WASTE

Summary of Total Lead Concentrations (mg/kg)

(Regulatory Threshold = 1,000 mg/kg)

Location Mean Standard 90% Upper Median Minimum Maximum Number of Appropriate

Deviation Confidence Samples Number of

Interval Samples

Facility A 2,202 20.6 2,403 2,130 1,720 3,280 9 <1

Facility B 1,653 95.5 2,058 1,860 701 2,640 9 <1

Facility C 2,026 56.3 2,285 2,035 1,060 3,420 14 <1

Summary of Total Copper Concentrations (mg/kg)

(Regulatory Threshold = 2,500 mg/kg)

Location Mean Standard 90% Upper Median Minimum Maximum Number of Appropriate

Deviation Confidence Samples Number of

Interval Samples

Facility A 1,933 694 3,155 1,360 465 12,200 9 3

Facility B 4,346 4,44 9,353 2,210 433 53,300 9 11

Facility C 1,343 349 1,887 892.5 628 8,890 14 <1

Summary of Total Zinc Concentrations (mg/kg)

(Regulatory Threshold = 5,000 mg/kg)

Location Mean Standard 90% Upper Median Minimum Maximum Number of Appropriate

Deviation Confidence Samples Number of

Interval Samples

Facility A 6,685 79.2 7,385 6,820 4,200 9,420 9 <1

Facility B 5,806 943 8,182 5,160 583 19,300 9 3

Facility C 8,089 323 9,320 8,045 4,230 17,400 14 <1
42

Appendix 5.

TREATED SHREDDER WASTE

Summary of Soluble Lead Concentrations (mg/l)

(Regulatory Threshold = 5.0 mg/l)

Location Mean Standard 90 % Upper Median Minimum Maximum Number of Appropriate

Deviation Confidence Samples Number of

Interval Samples

Facility A 29.3 0.70 33.6 28.5 16.3 45.6 9 <1

Facility B 4.39 5.80 10.3 1.61 0.25 68.3 9 172

Facility C 18.9 5.39 26.9 15.3 3.55 34.3 14 <1

Summary of Soluble Cadmium Concentrations (mg/l)

(Regulatory Threshold = 1.0 mg/l)

Location Mean Standard 90 % Upper Median Minimum Maximum Number of Appropriate

Deviation Confidence Samples Number of

Interval Samples

Facility A 1.56 0.32 1.72 1.45 1.22 2.15 9 <1

Facility B 0.33 0.50 0.58 0.78 0.0 1.55 8 1

Facility C N/A N/A N/A N/A 0.70 0.70 1 N/A

Summary of Soluble Zinc Concentrations (mg/kg)

(Regulatory Threshold = 250 mg/l)

Location Mean Standard 90 % Upper Median Minimum Maximum Number of Appropriate Number

Deviation Confidence Samples of Samples

Interval

Facility A 439 6.85 491 445 308 659 9 <1

Facility B 33.8 129 132 3.39 1.34 1,150 8 <1

Facility C 304 63.5 327 314.5 171 396 14 3
43

Appendix 6.

Summary of Total PCB Concentrations (mg/kg) in Untreated Shredder Waste

(Regulatory Threshold = 50 mg/kg)

Location Mean Standard 90 % Upper Median Minimum Maximum Number of Appropriate

Deviation Confidence Samples Number of

Interval Samples

Facility A 14.0 0.56 16.0 14.7 5.3 22.5 14 <1

Facility B 7.03 1.81 10.7 5.59 0.59 32.7 12 <1

Facility C 28.0 6.85 42.4 18.6 14.2 129 9 <1

Summary of Total PCB Concentrations (mg/kg) in Treated Auto Shredder Waste

(Regulatory Threshold = 50 mg/kg)

Location Mean Standard 90 % Upper Median Minimum Maximum Number of Appropriate

Deviation Confidence Samples Number of

Interval Samples

Facility A 4.89 1.57 5.46 4.5 3.0 7.2 9 <1

Facility B 8.91 2.36 13.7 9.14 2.57 45.1 9 <1

Facility C 22.7 1.88 27.6 26.5 10.2 41.1 14 <1
44

References

Environmental Liability Management, Inc. 1991. Beneficial Use of Automobile Shredder

Residue in Landfills. Prepared for the Recycling Research Foundation.

Letter dated March 9, 1984, from DTSC to Dr. Kenneth Hekimian RE: Disposal of

Automobile Shredder Wastes from Hugo Neu-Proler and Clean Steel, Inc.

Baumgartner & Associates, Inc. 1992. Shredder Residue: Environmental Information and

Characteristics under RCRA. Prepared for the Recycling Research Foundation,

Washington, DC.