EPA/600/R-07/068 

April 2007 

Testing Nickel Emissions from 

Metal Finishing Operations 

(Phase 2) 

Final Report 

National Risk Management Research Laboratory 

Office of Research and Development 

U.S. Environmental Protection Agency 

 Cincinnati, Ohio 45268 

Prepared by 

Scientific Control Laboratories, Inc. 

3158 S. Kolin Avenue 

Chicago, IL 60623 

Under USEPA Order Number: EP-C-05-016 

i 
FOREWORD 

The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the 

Nation's land, air, and water resources. Under a mandate of national environmental laws, the 

Agency strives to formulate and implement actions leading to a compatible balance between 

human activities and the ability of natural systems to support and nurture life. To meet this 

mandate, EPA's research program is providing data and technical support for solving 

environmental problems today and building a science knowledge base necessary to manage our 

ecological resources wisely, understand how pollutants affect our health, and prevent or reduce 

environmental risks in the future. 

The National Risk Management Research Laboratory (NRMRL) is the Agency's center for 

investigation of technological and management approaches for preventing and reducing risks 

from pollution that threaten human health and the environment. The focus of the Laboratory's 

research program is on methods and their cost-effectiveness for prevention and control of 

pollution to air, land, water, and subsurface resources; protection of water quality in public water 

systems; remediation of contaminated sites, sediments and ground water; prevention and control 

of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with both public and 

private sector partners to foster technologies that reduce the cost of compliance and to anticipate 

emerging problems. NRMRL's research provides solutions to environmental problems by: 

developing and promoting technologies that protect and improve the environment; advancing 

scientific and engineering information to support regulatory and policy decisions; and providing 

the technical support and information transfer to ensure implementation of environmental 

regulations and strategies at the national, state, and community levels. 

This publication has been produced as part of the Laboratory's strategic long-term research plan. 

It is published and made available by EPA's Office of Research and Development to assist the 

user community and to link researchers with their clients. 

Sally Gutierrez, Director 

National Risk Management Research Laboratory 

ii 
PREFACE 

This report provides an overview of nickel plating air emissions and waste release issues 

within the nickel plating industry. It is the objective of this report to assist the metal 

finishing community and specifically, those involved with nickel plating operations, with 

the management of environmental challenges that result from wastes that are potentially 

generated by nickel plating. Both the electrodeposition and electroless deposition 

processes for nickel plating have been profiled to examine resultant waste streams and 

potential releases. 

Nickel plating practitioners are challenged to making a high-quality product that meets 

the needs of the customer while being competitive within the market. Furthermore, 

nickel plating practitioners must deal with environmental, regulatory, and technical, 

requirements to protect human health and the environment. This report serves as an 

advisory to nickel plating practitioners by providing technical information to reduce 

environmental impacts and lower the liabilities associated with environmental releases. 

NOTICE 

This document has been reviewed in accordance with the U.S. Environmental Protection 

Agency=s peer and administrative review policies and approved for publication. Mention 

of trade names or commercial products does not constitute endorsement or 

recommendation for use. 

ACKNOWLEDGMENTS 

This report was developed for the U.S. Environmental Protection Agency (EPA), 

Sustainable Technology Division in Cincinnati, Ohio under Contract No.: EP-C-05-016. 

David Ferguson, Office of Research and Development (ORD), National Risk 

Management Research Laboratory (NRMRL), Multimedia Technology Branch 

coordinated the preparation of this report, and is the co-author with Frank Altmayer, Jeff 

Zac and Jolie Zac of Scientific Control Laboratories, Inc. of Chicago, Illinois. 

iii 
Table of Contents 

Page Number 

Section 0.0 Foreword ii 

 Preface iii 

Notice iii 

 Acknowledgments iii 

Table of Contents iv 

Abstract v 

Section 1.0 Project Description and Objectives 1 

Section 2.0 Project Organization 6 

Section 3.0 Procedure 7 

Section 4.0 Discussion of Sampling and Analytical Procedures 8 

Section 5.0 Summary of Results 12 

Section 6.0 Discussion of Results 28 

Section 7.0 Conclusions 36 

Appendix A: Calculation Worksheets for Nickel Stack Emissions 

Appendix B: Calculation Worksheets for Ambient Nickel Concentrations and 

Field Log Sheets 

Appendix C: Photographs 

Appendix D1-2: Stack Testing Field Data Sheets and Calibration Sheets 

Appendix E1-4: Laboratory QA/QC Data for Stack Testing Samples 

Appendix F: Laboratory QA/QC Data for Ambient Air Samples 

Appendix G: Plating Solution Laboratory Report 

Appendix H: Sample Chain of Custodies 

Appendix I: Process Data Sheets 

Appendix J: Stack Test Schematics 

iv 
ABSTRACT: 

Nickel emissions from electroplating operations are of concern to EPA. Therefore, EPA has 

determined that it would be useful and important to obtain actual nickel emission data from 

nickel plating operations using EPA-Approved testing methods (both Method 29 and Method 

306A). The five nickel plating processes tested in this project were: Electroless Nickel, Rack 

Watts Nickel, Barrel Watts Nickel, Nickel Sulfamate, and Wood’s Nickel Strike Plating. In 

addition, by modifying some of the operating parameters (i.e. surface tension, agitation methods, 

etc.), EPA can determine the impact of these operational changes on nickel emissions. 

The stack testing was conducted over a two year span from June of 2004 through January of 

2006. Based on the stack testing results, it was concluded that: 

- Nickel emissions from typically-operated Rack Watts Nickel and Rack Nickel 

Sulfamate tanks (wetting agent, no mesh pad, air agitation) are not very significant 

(<0.05 mg/dscm). 

- Nickel emissions from uncontrolled and vented Electroless Nickel, Barrel Nickel, and 

Wood’s Nickel Strike plating are significant (greater then 0.1 mg/dscm), but can be 

significantly reduced (49% to 92%) by employing eductors, wetting agents, or simple 

mesh pads. 

- Wetting agents, simple mesh pads, and eductors can be used to reduce nickel 

emissions from these processes with varying degrees of success. Simple mesh pads 

were found to be the most favorable because they outperformed wetting agents and 

eductors, are less expensive, and are totally external to the plating process (no impact 

on the plating chemistry). 

Although the results of the study indicate that USEPA Method 306A and 

USEPA Method 29 provide similar results when measuring nickel emissions from Electroless 

Nickel, Watts Nickel, and Wood’s nickel strike, further testing needs to be conducted on a 

controlled process or conducted simultaneously to determine whether Method 306A truly is an 

acceptable alternative to Method 29 for measuring nickel emissions from nickel plating 

processes in general. 

v 
Section 1.0 PROJECT DESCRIPTION AND OBJECTIVES 

Purpose and Background 

The nickel plating industry is a large part of the metal finishing community in the United States. 

It consists of job shops (independently owned plating businesses) and captive shops (metal 

finishing operations contained in larger manufacturing facilities). There are over 3,000 U.S. job 

shops that average fewer than 50 employees each with annual sales of, approximately $5 million. 

Captive shops that support larger manufacturing facilities can vary in size depending on their 

role within the company. The metal finishing industry is regulated for environmental protection 

and occupational health and safety due to the nature of the processes and materials required to 

satisfy industrial and public consumer demand. Nearly all manufactured products require some 

type of surface finishing. Consumers demand products that have aesthetic appeal, will not 

deteriorate, and have durability. The nickel plating industry provides a product that improves 

appearance, slows or prevents corrosion, changes magnetic properties, and increases strength and 

resistance to wear for manufactured parts and products. 

Most of the nickel plating industry is located in or near major metropolitan areas and may 

generate air emissions, water discharges, and solid wastes that add to overall pollution concerns. 

Pollution abatement costs and expenditures for the metal finishing industry comprise nearly 20% 

of its budget. Industry representatives are working together with government, trade associations, 

and professional organizations to encourage technological advances that lead to more efficient, 

cleaner production while reducing waste generation and control costs. 

Nickel plating is most commonly applied though the utilization of aqueous chemical reagents by 

means of electroplating or via a chemical reducing agent (a process that is referred to as 

electroless plating). Typical constituents of nickel electroplating solutions include nickel sulfate 

(or nickel sulfamate) nickel chloride, and boric acid, along with inorganic or organic additives 

that modify the crystal structure of the nickel deposit. While a variety of formulations for nickel 

plating exists, the Watts, Woods, and Sulfamate processes comprise the majority of the 

formulations used by the metal finishing industry. Also, electroless nickel is used throughout the 

industry and these process solutions are based on nickel sulfate plus a reducing agent containing 

boron or phosphorus. The phosphorus-based solutions produce nickel alloy deposits ranging 

from about 4% to about 12% phosphorus. 

Nickel emissions from electroplating operations are of concern to EPA. Air emission estimation 

for electroplating is described in EPA’s AP42 Manual. As part of this manual, the AP42 states: 

“Emissions from plating operations other than chromium electroplating can be estimated using 

the emission factors and operating parameters for chromium electroplating.” Based on this 

theory, EPA developed a computer based Metal Finishing Facility Risk Screening Tool 

(MFFRST) which estimates emissions from electroplating operations. The tool is believed to be 

very accurate for chromium emissions, however, there was a need to validate air emissions for 

other metals such as nickel. 

1
In Phase I of this project, it was determined that the MFFRST Model that used the AP42 

methodology was not very accurate in estimating nickel emissions from nickel plating 

operations. Therefore, EPA has determined that it would be useful and important to obtain more 

actual nickel emission data from nickel plating operations to improve AP42 estimates using 

EPA-Approved testing methods (both Method 29 and Method 306A). 

In addition, by modifying some of the operating parameters from one test to another within the 

plating process (i.e. surface tension, agitation methods, etc.) and then comparing the test results, 

EPA can determine the effects of these operating parameters on nickel emissions. 

Process, Site, Facilities Tested 

Actual data was collected by stack testing various types of nickel plating processes, operating 

under several different conditions, using EPA-Approved procedures. Similar testing was also 

conducted in Phase 1 of this project in 2004. 

For Phase 2, the exhausted air from five different types of nickel plating processes was sampled 

and analyzed for nickel in order to obtain the nickel emissions from each process. These nickel 

plating processes were all production lines located in actual plating facilities. Each nickel 

plating process was tested several times under various conditions in order to observe the effects 

of that condition on nickel emissions. There were a total of twenty-three (23) actual stack tests 

conducted during this phase. The nickel plating processes that were tested were: Electroless 

Nickel Plating, Rack Watts Nickel Plating, Barrel Watts Nickel Plating, Rack Nickel Sulfamate 

Plating, and Rack Woods Nickel Strike Plating. The various conditions under which each of 

these processes was tested are summarized in the Table 1. 

Some nickel plating processes were tested more (varying more operating conditions) than other 

nickel plating processes (i.e. Rack Watts Nickel is tested under more operating conditions than 

Woods Nickel Strike). The total number of stack tests (23) was based solely on the budget of the 

project. The decision on which plating processes were tested more than others was based on the 

popularity of that process in the industry. In other words, Rack Watts Nickel is far more 

common in the industry than Woods Nickel Strike so more emphasis (i.e. more conditions were 

varied) was given to Rack Watts Nickel. 

The testing sites for each of these nickel plating processes were as follows: 

1. Electroless Nickel Plating 

Facility: Reliable Plating Company 

Site: 1538 West Lake Street 

 Chicago, IL 60607 

2. Rack Watts Nickel Plating 

Facility: America’s Best Quality Coatings 

2
Site: 1602 S. First Street 

 Milwaukee, WI 53204 

3. Barrel Watts Nickel Plating 

Facility: Artistic Plating Company 

Site: 405 W. Cherry Street 

 Milwaukee, WI 53212 

4. Rack Nickel Sulfamate Plating 

Facility: Elite Finishing, LLC 

Site: 3270 S. 3rd Street 

 Milwaukee, WI 53207 

5. Rack Woods Nickel Strike Plating 

Facility: Artistic Plating Company 

Site: 405 W. Cherry Street 

 Milwaukee, WI 53212 

The six (6) stack tests that were completed on nickel plating processes as Phase 1 of this project 

are also included in Table 1 (identified as “Completed - Phase 1”). 

The actual nickel emission results from Phase 1 and Phase 2 were also used to estimate the 

effects of several plating operating parameters on nickel emissions. Based on the operating 

conditions selected and summarized in Table 1, we were able to estimate the effects of the 

following operating conditions/parameters on nickel emissions: 

- air agitation versus pump (eductor) agitation 

- the use of wetting agents to control the surface tension of the plating 

solution 

- the use of simple mesh pads on the exhaust hood to control splashing 

- the ratio of nickel emissions attributed to electrolysis (electroplating) 

versus attributed to barrel transfer (entrainment from splashing) in barrel 

plating 

- the ratio of nickel emissions attributed to plating versus attributed to 

agitation and evaporation in electroless nickel plating 

- the type of stack testing used (Method 29 versus Method 306A) 

Table 2 summarizes these selected process parameters and which tests were compared to each 

other when estimating the effects of the selected parameter. 

The data collected in Phase 1 was also used in Phase 2 to compare nickel emissions from various 

nickel processes and from same nickel processes operated under different conditions. The results 

3
from Phase 1 and Phase 2 are comparable because identical sampling and testing methodologies 

was used in both phases (i.e. Method 29, three individual test runs per stack test, etc.) and 

because, in many cases, the same nickel plating site was tested in both Phase 1 and Phase 2 

(except under different operating conditions). 

4
 Surface Tension/ Air Agitation/ Tank 

# Process Wetting Agent Mesh Pad Eductor Loading Status Sit

1 Electroless Nickel NA No Low Completed- Phase 1 Re2 Electroless Nickel NA No Low Completed- Phase 1 Re3 Electroless Nickel High Phase 2 (USEPA-A) Re4 5 6 

Electroless Nickel 

Electroless Nickel 

Electroless Nickel 

NA 

NA 

Yes 

No 

AirAir

Air 

 Eductor 

 Eductor 

Air 

High High 

High 

Phase 2 (USEPA-B) Phase 2 (SCL 3) 

Phase 2 (SCL 4) 

Re

Re

Re

8 9 

Rack Watts (bright)Rack Watts (bright)

NA 

NA 

 Yes (30s) Yes  Yes (30s) No Eductor High 

Completed- Phase 1 Completed- Phase 1 

SitSit

10 Rack Watts (bright) No (45-60) Yes Eductor High Phase 2 (USEPA- C) AB11 12 13 

Rack Watts (bright) Rack Watts (bright) 

Rack Watts (bright)

No (45-60) No (45-60) No 

 Yes (30s) No 

Yes No Air 

Air 

Air 

 Eductor

High 

High 

High 

 High 

Phase 2 (SCL 1) 

Phase 2 (SCL 10) 

 Phase 2 (USEPA- D) 

AB

AB

AB

14 Rack Watts (bright) Yes Phase 2 (SCL 2) AB15 Rack Watts (bright) Yes Phase 2 (SCL 2) AB16 Barrel Watts (dull) Yes (33) Yes 17 Barrel Watts (bright) No (50s) Yes 18 Barrel Watts (dull) No (45-60) Yes Yes 

Air 

Air 

 NA High 

High 

 High 

Completed- Phase 1Completed- Phase 1

 Phase 2 (USEPA-E) 

 Art Art

Art

19 Barrel Watts (dull) No (45-60)20 Barrel Watts (dull) Yes (30s) No 21 Barrel Watts (dull) Yes (30s) No

 No 

NA 

NA 

High 

High 

 High  High 

 Phase 2 (SCL-9)*** 

 Phase 2 (USEPA-F) 

 Phase 2 (SCL-8)*** 

Art

Art

Art

22 Rack Sulfamate Yes (30s) 23 Rack Sulfamate Yes (30s) Yes 25 Rack Sulfamate Yes (30s) No 

NA

NA 

NA

 Eductor 

 Eductor 

High 

 Phase 2 (SCL-5) 

 Phase 2 (SCL-7) 

 Phase 2 (USEPA-G) 

Eli

Eli

Eli

26 Rack Sulfamate Yes (30s) 

No Air High 

 Phase 2 (USEPA-G) Eli

27 Woods Strike (Rack) No (50-60)No 28 Woods Strike (Rack) Yes (30s) Yes 7 Woods Strike (Rack) No (50-60)No 

 No 

No 

 Yes Air 

NA

High 

High 

High 

 High 

 Phase 2 (USEPA-I) 

 Phase 2 (USEPA-H) 

 Phase 2 (SCL-6) 

Art

Art

Art

24 Woods Strike (Rack) Yes (30s) 29 Woods Strike (Rack) Yes (30s) No NA NA High 

 Phase 2 (SCL-11) 

 Phase 2 (USEPA-H) 

Art

Art

NA High 

Yes *** Absolutely no barrel transfer during testing NA High High 

TABLE 1 

USEPA Nickel Project Process Summary

5
TABLE 2 

Nickel Plating Process Operating Condition/Parameter Tests Compared to Evaluate the Affec

Condition/Parameter on Nickel Emiss

Air Agitation versus Pump (Eductor) Agitation 3-4, 5-6 (Electroless Nicke

8-9, 10-11, 13-14 (Rack Watts) 22-23 (Rack Sulfamate) 

The Use of Wetting agents 8-12, 10-13, 11-14, (Rack Watts) 

16-17, 18-20, 19-21, (Barrel Watts) 27-28, 7-24 (Rack Woods Str

 The Use of Simple Mesh Pads in Exhaust Hood 4-5, 3-6 (Electroless Nicke

11-12, 9-13, 8-14 (Rack Watts) 16-20 17-18 (Barrel Watts) 23-25 (Rack Sulfamate) 7-27, 24-28 (Woods Nickel) 

The Ratio of Nickel Emissions Attributed to Electrolysis (electroplating) Versus Attributed to Barrel Transfer (entrainment from splashing) in Barrel Plating 

17-19, 16-21 (Barrel Watts) 

The Ratio of Nickel Emissions Attributed to Plating Versus Attributed to Agitation/Evaporation in Electroless Nickel Plating 

1-6, (Electroless Nicke

The Type of Stack Testing Method Used (Method 29 versus Method 306A) 

1-2 (Electroless Nickel14-15 (Rack Watts) 22-26 (Rack Sulfamate) 28-29 (Rack Woods Strik

6
Project Objectives 

The objectives of this project were to 1) develop actual nickel air emission data using EPAApproved Methods 29 and 306A that may also be used in the future to establish regulations 

for nickel emissions and/or revise the AP-42 Methodology and consequently the MFFRST 

Model, 2) compare the total nickel emissions obtained using EPA Method 29 and EPA 

Method 306A to determine whether Method 306A is a viable alternative to Method 29 for 

determining nickel emissions, and 3) evaluate the factors that affect nickel emissions such as 

surface tension, product loading, type of process solution and type of agitation used in the 

process. 

Section 2.0 PROJECT ORGANIZATION 

Contacts 

Organization Contact 

USEPA David Ferguson (513-569-7518) 

Scientific Control Laboratories, Inc. Frank Altmayer/Jeff Zak (773-254-2406) 

Artistic Plating Company John Lindstedt (414-271-8138) 

ABQC Company Matthew Kirchner (414-649-4900) 

Elite Finishing Jaime Maliszewski (414-489-9710) 

Reliable Plating Company Jim Greenwell (312-421-4747) 

ETE Michael Huenink (262-784-2434) 

QA Managers 

Linda Kenny 

Scientific Control Laboratories, Inc. 

3158 S. Kolin Avenue 

Chicago, IL 60623 

773-254-2406 

Lauren Drees 

EPA QA Manager 

Project Participants and Responsibilities 

Name Responsibility 

David Ferguson, USEPA USEPA Project Manager 

Frank Altmayer, SCL Project Manager 

7
Name Responsibility 

Jeff Zak, P.E., SCL Planning Coordination, 

Sample Collection, Sample Custody, 

Physical Measurement, Process 

Measurements, Data Validation, Data 

Reduction, Report Preparation 

Linda Kenny, SCL Analytical Measurements, 

 QA Manager 

Michael Huenink, ETE Sample Collection, Physical 

 Measurements, Process

 Measurements 

John Lindstedt, Artistic Testing Site Contact 

Jaime Maliszewski, Elite Testing Site Contact 

Matthew Kirchner, ABQC Testing Site Contact 

Jim Greenwell, Reliable Testing Site Contact 

Chicago Plastics Mesh Pad Supplier 

Serfilco Eductor Supplier 

Section 3.0 PROCEDURE 

General Approach and Testing Methodology 

Three (3) test runs were conducted on each of the twenty-three (23) different nickel plating 

operations/conditions listed in Table 1 in order to measure the nickel concentration in the air 

emitted from each of these processes. Twenty (20) of the tests were conducted in accordance 

with EPA-Approved Method 29 of 40 CFR Part 60 Appendix A-8 (A copy of Method 29 is 

included in Appendix A). All applicable operating parameters were observed and recorded 

throughout the tests (i.e current density, temperature of plating solution, amperage, plating 

solution concentration, tank dimensions, etc.). 

The nickel emissions from the remaining three (3) processes/conditions were measured in 

accordance with Method 306A of 40 CFR Part 63, Appendix A (with a couple of minor 

deviations detailed in Section 4.0). A copy of Method 306A of 40 CFR Part 63 Appendix A 

is included in Appendix B of this QAPP. The purpose of these tests was to compare the 

results obtained from Method 29 and Method 306A. 

8
The stack sampling was conducted during normal plating operations at the selected facilities. 

Since normal plating operations at job-shop electroplating facilities are inherently non-steady 

state, the stack sampling did not rely on steady state conditions of the plating operations. 

In order to ensure that the ventilation systems on each of the nickel plating processes were 

operating efficiently (capturing and exhausting all of the nickel emissions from the process), 

the ambient air near each process was also monitored/tested during the test runs. The 

ambient air was tested with two (2) OSHA-approved internal air monitors at each of the 

processes. The arithmetic mean of the two results was compared to OSHA worker exposure 

limits for nickel in order to grade the efficiency of the ventilation systems. If the average 

nickel concentration in the ambient air was below OSHA worker exposure limits for nickel, 

the ventilation system for that specific process was deemed efficient. 

Sampling/Monitoring Points 

1) Sampling Port Locations for Nickel Emissions Testing 

The locations of the sampling ports in the exhaust stacks of each of the five 

individual nickel plating processes were determined in accordance with 

Section 8.1.2 of Method 29 of 40 CFR Part 60 Appendix A-8. Section 8.1.2 

of Method 29 references Section 8.2.1 of Method 5 of 40 CFR Part 60 

Appendix A which further references Method 1 of 40 CFR Part 60 Appendix 

A. Section 11.0 of Method 1 states that the sampling ports must be positioned 

at least two (2) stack or duct diameters downstream and a half diameter 

upstream from any flow disturbance. The exhaust systems from all five nickel 

plating testing sites were constructed so that they met this sampling port 

location requirement. 

The sampling point locations were recorded into the field log sheets included 

with Appendix D of this report. 

2) Traverse Point Locations for Nickel Emissions Testing 

The location of the sampling (traverse) points within the exhaust stacks of 

each of the five individual nickel plating processes were determined in 

accordance with Section 11.0 of Methods 1 and 1A of 40 CFR Part 60 

Appendix A. Method 1 is to be used for ducts with diameters greater than 12 

inches. Method 1A is to be used for round ducts with a diameter less than 12 

inches. The traverse point locations were documented and recorded on the 

field log sheets located in Appendix D of this report. 

3) Location of Ambient Air Monitors 

The ambient air monitors used to determine the effectiveness of the 

ventilation systems of each of the five nickel plating processes were 

positioned on stands or taped to columns at the perimeter of the nickel plating 

tanks. 

4) Frequency of the Sampling Events: 

9
Three (3) stack tests were conducted at each of the 29 testing conditions listed 

in Table 1 with the exception of Condition 13 in which processing problems 

limited the testing to one (1) stack test (See page 32 for a detailed 

explanation). Otherwise, all three test runs were conducted within the same 

day under similar operating conditions. 

Section 4.0 DISCUSSION OF SAMPLING/ANALYTICAL PROCEDURES 

Sampling Procedures 

The sampling procedures described in Section 8.0 of EPA Method 29 of 40 CFR Part 60 

Appendix A-8 (which further references Section 8.5 of Method 5 of 40 CFR Part 60 

Appendix A-3) were followed when sampling the air emitted from twenty (20) of the twenty 

three nickel plating process scenarios listed in Table 1 for Phase 2. A copy of Method 5 of 

40 CFR Part 60 Appendix A-3 was included in Appendix G of the approved QAPP. 

The following parameters were recorded from each nickel plating processes throughout the 

testing/sampling: 

- Temperature of Plating Solution 

- Current Density (where applicable) 

- Plating Bath Concentration, including surface tension 

- Tank Dimensions 

- Amperage/Voltage (where applicable) 

- Types of Parts being Plated 

- Plating Time 

- Freeboard Height 

- Air Agitation Rate (where applicable) 

- Solution Circulation Rate 

After the samples were collected from each test run, each sample container was marked with 

the following data: 

- Nickel Plating Process Type 

- Site Location 

- Date 

- Run # 

Scientific Control Laboratories was responsible for completing the chain of custodies for all 

the samples taken at the site(s). The samples were in the custody of Scientific Control 

personnel at all times from each site to the Scientific Control Laboratories where they were 

analyzed for nickel. There was no splitting of the samples. Scientific Control Laboratories 

was responsible for all sampling and analysis. Environmental Technology and Engineering 

was subcontracted to supply the sampling equipment and calibration of sampling equipment. 

10
Stack Testing Using USEPA Method 306A 

The sampling procedure described in Section 8.0 of EPA Method 306A of 40 CFR Part 63 

Appendix A (Included in Appendix C of approved QAPP) was followed when sampling the 

air emitted from three of the twenty three nickel plating process scenarios listed in Table 1 

(with the exception of the minor deviations listed below).. 

The following factors were recorded from the nickel plating processes throughout the 

Method 306A testing/sampling: 

- Temperature of Plating Solution 

- Plating Bath Concentration 

- Tank Dimensions 

- Types of Parts being Plated 

- Freeboard 

- Air Agitation Rate (where applicable) 

- Solution Circulation Rate 

After the samples were collected from each test run, each sample container was marked with 

the following data: 

- Nickel Plating Process Type 

- Site Location 

- Date 

- Run # 

Scientific Control Laboratories, Inc. (SCL) was responsible for completing the chain of 

custodies for all the 306A samples taken at the site. The samples were in the custody of SCL 

personnel at all times from the site to the SCL laboratory where they were analyzed for 

nickel. There will be no splitting of the samples. SCL was responsible for all sampling and 

analysis; there were no subcontractors involved in this part of the project. 

Modifications to Sampling Procedures in Method 306A 

There were a few deviations to the EPA-Approved Method 306 A Procedure for this project. 

These modifications were discussed in the approved Quality Assurance Project Plan (QAPP) 

and include the following: 

1) Section 8.1.1.9.1 B Instead of using 0.1N NaOH or 0.1N NaHCO3 as absorbing solution 

in the first impinger of the sampling train, a mixture of 5% HNO3 and 10% H2O2 was 

used. This absorbing solution is the recommended absorbing solution for nickel as 

stipulated in EPA-Approved Method 29 of Appendix A of 40 CFR Part 60. 

2) The current Method 306A (dated October 17, 2000) is a revision of the original version 

of Method 306A (dated January 25, 1995). The author of the original method (Frank 

11
Clay of the USEPA) has been very critical of the new method. Mr. Clay has written an 

article, A Revised Method 306A- Second Review and Critique, that details the errors, 

omissions, and superfluous material that are found in the new 306A Method and offers 

some recommendations on how to improve the current method. After reading Mr. Clay’s 

article and based on our experience of performing Method 306A, Scientific Control 

Laboratories concurred with Mr. Clay’s opinion and included the following applicable 

recommendations (minor deviations) when using Method 306A. 

1. A rocker switch was used to start and stop the sampling train instead of a bypass 

valve. 

2. All runs were performed in a single day. 

3. The cotton ball in the third impinger was omitted from the sampling train. 

4. When recovering the sample, the tubing and nozzle (and the tubing between the first 

and second impinger) was rinsed three times in each direction with the absorbing 

solution instead of two. 

A copy of Mr. Clay’s article that justifies these recommendations is located in Appendix D of 

the approved QAPP. It is SCL’s opinion that these proposed modifications are minor 

deviations that, in no way, affected the accuracy of the sampling results. 

Ambient Air Monitoring 

The sampling procedures as detailed in Section 5 (specifically Method 5.4) of OSHAApproved Method ID-121 were followed when monitoring the internal air near the five (5) 

nickel plating processes. This sampling was conducted during all twenty-three (23) tests. A 

copy of OSHA Method ID-121 is included in Appendix F of the QAPP. Scientific Control 

Laboratories calibrated the air sampling pumps prior to each sampling. 

Method 29 and Method 306A Field Blanks 

Field Blanks were used to determine the quantity, if any, of nickel contamination in the 

virgin scrubbant (HNO3/H2O2) and rinse (HNO3) materials. The scrubbant material is used 

to capture the nickel emitted from the various nickel plating processes. The rinse material is 

used to rinse the probe and scrubbers after the testing. The nickel concentration present in 

the virgin scrubbant and rinse materials, if any, is subtracted from the nickel concentrations 

obtained from the actual testing. 

Before testing, batches of virgin scrubbant and rinse materials were formulated at Scientific 

Control Laboratories. 

Laboratory Analyses 

The samples obtained from the stack testing were analyzed for nickel in accordance with the 

methods detailed in Section 11.0 of Method 29 of 40 CFR Part 60 Appendix A or Section 11 

of Method 306A of 40 CFR Part 63 Appendix A. The analyses were conducted by Atomic 

Absorption-AA (Section 11.1.2 of Method 29). Only total nickel emissions were measured 

12
from the various nickel plating processes using Method 29. Particulates were not measured 

as part of this project. 

The samples obtained from the OSHA internal air monitoring were analyzed for nickel in 

accordance with Section 6 of OSHA-Approved Method ID-121. The analyses were 

performed by ICAP-AES. 

The QA/QC program(s) described in Sections 9.0 and 10.0 of Method 29 of 40 CFR Part 60 

Appendix A-8 and Method 306A of 40 CFR Part 63 Appendix A were followed when 

sampling the nickel plating system stacks. The QA/QC program described in Sections 9.0 

and 10.0 of Method 29 of 40 CFR Part 60 Appendix A were followed when analyzing the 

resultant samples for nickel. 

The laboratory QA/QC data for the stack testing samples is included in Appendix E of this 

report. 

The QA/QC program described in Section 6 of OSHA-Approved Method ID-121 was 

followed when analyzing the filter samples from the internal air monitoring for nickel. The 

laboratory QA/QC data for the ambient air samples is included in Appendix F of this report. 

Section 5.0 SUMMARY OF RESULTS 

The results of the project are presented in the following tables: 

Table 3. Summary of Nickel Emissions Obtained from Phase 1 and Phase 

2 Stack Testing 

Table 4. Comparison of Nickel Emissions (Air Agitation versus Eductors) 

Table 5. Effects of Wetting Agents on Nickel Emissions 

Table 6. Effects of Mesh Pads on Nickel Emissions 

Table 7. Effects of Barrel Transfer on Nickel Emissions from Watts Nickel 

Barrel Plating 

Table 8. Effects of Product Loading on Nickel Emissions from Electroless 

Nickel Plating 

Table 9. Nickel Emissions Method 29 Compared to Method 306A 

Table 10A-10E 

Operating Parameters Observed During Stack Testing for Nickel 

Emissions 

Table 11. Ambient Air Nickel Concentrations Observed During Stack 

Testing 

13
The data presented in Table 3 is the actual nickel emission concentrations from each of the 

three (3) individual test runs from all twenty-nine conditions (29) that were tested (including 

the six conditions tested as part of Phase 1). The nickel emission concentrations were 

calculated using the analytical data obtained in accordance with the Method 29 Stack Testing 

procedure (or the equivalent Method 306A Stack Testing Procedure) and were performed in 

accordance with Section 12 of Method 29 of 40 CFR Part 60 Appendix A-8 (or the equivalent 

Section 12 of Method 306A depending on which method was used for the sampling). The data 

used for these calculations for the twenty-three Phase 2 testing conditions is included in 

Appendix A of this report. The data used for the calculations for the six Phase 1 testing 

conditions is included in Appendix A of the Final Phase 1 Report. The average of the three (3) 

test runs for each of the twenty-nine (29) conditions is also reported in Table 3. 

The data presented in Table 4 summarizes the effects of air agitation versus eductors on nickel 

emissions in electroless nickel, Watts nickel, and nickel sulfamate solutions based on the 

testing comparison protocol listed in Table 2. 

The data presented in Table 5 summarizes the effects of wetting agents on nickel emissions in 

Watts nickel, nickel sulfamate, and Woods nickel strike solutions based on the testing 

comparison protocol listed in Table 2. 

The data presented in Table 6 summarizes the effects of mesh pads on nickel emissions in 

electroless nickel, Watts nickel, nickel sulfamate, and Woods nickel strike solutions based on 

the testing comparison protocol listed in Table 2. 

The data presented in Table 7 summarizes the effects of barrel transfer on nickel emissions 

from Watts nickel barrel plating based on the testing comparison protocol listed in Table 2. 

The data presented in Table 8 summarizes the effects of product loading on nickel emissions 

from Electroless Nickel Plating based on the testing comparison protocol listed in Table 2. 

The data presented in Table 9 are the stack test results obtained from testing the same process 

(electroless nickel, Watts nickel, nickel sulfamate, and Woods nickel strike) using two different 

sampling procedures (EPA Method 29 and EPA Method 306A). 

The data presented in Table 10A through 10E are the individual nickel plating process 

operating parameters that were recorded during the stack tests. 

The data presented in Table 11 are the ambient air nickel concentrations as calculated using the 

analytical data obtained in accordance with OSHA-Approved Method ID-121. These 

calculations were performed in accordance with Section 7 of OSHA-Approved Method ID121. The OSHA eight (8) hour, time-weighted average PEL for nickel is also included in the 

table for comparison purposes. The data used for these calculations are included in Appendix B 

of this report. 

14
 Surface Tension/ Air Agitation/ Tank Results (m

# Process Wetting Agent** Mesh Pad Eductor Loading Run #1 Run #2 Run #3 

1* Electroless Nickel Low 0.478 0.126 0.220 2* Electroless Nickel (306A) NA Low 0.060 0.311 0.381 3 Electroless Nickel 0.011 0.006 0.005 4 5 6 

Electroless Nickel 

Electroless Nickel NA 

Electroless Nickel 

NA 

No 

NA No 

Yes 

No 

Air 

Air 

Air 

 Eductor

 Eductor

Air 

High 

 High 

 High 

High 

 0.024 

 0.142 

0.124

0.012 

0.192 

 0.313

0.004 

0.111 

 0.505 

8* Rack Watts (bright) Yes NA (38) Yes 9* Rack Watts (bright) Yes NA (38) No Eductor High 

 0.048 

 0.016 

0.044 

0.027 

0.032 

0.028 

10 Rack Watts (bright) No (58) Yes Eductor High 0.043 0.003 0.016 11 Rack Watts (bright) No (57) Yes 12 Rack Watts (bright) No (57) No No 13 Rack Watts (bright) Yes (42) No 

Air High 

 Eductor High 

 0.057 

 0.051 

 0.015 

0.012 

0.133 

NA 

0.005 

0.056 

NA 

14 Rack Watts (bright) Yes (37) 15 Rack Watts (bright) (306A) Yes (37) Yes Air 

Air 

Air High 

High 

High 

 0.003 

0.014 

0.004 

0.008 

0.003/0.037

0.012 

16* Barrel Watts (dull) Yes (34) Yes 17* Barrel Watts (bright) No (57) Yes No Air High 

 0.080 

 0.975 

0.061 

1.495 

0.118 

0.921 

18 Barrel Watts (dull) No (68) Yes 0.009 <0.005 0.023 19 Barrel Watts (dull)*** No (68) No 20 Barrel Watts (dull) Yes (31) No 21 Barrel Watts (dull)*** Yes (31) 

NA 

NA 

NA 

High 

High 

High 

 0.056 

 0.009 

 0.023 

0.019 

0.004 

0.007 

0.228 

0.012 

0.009 

22 Rack Sulfamate Yes (39) 23 Rack Sulfamate Yes (44) Yes 25 Rack Sulfamate Yes (44) No 

NA 

NA 

NA 

High 

 Eductor High 

 Eductor High 

 High 

 High 

 0.022 

 0.018 

 0.004 

0.011 

0.013 

0.006 

0.010 

0.020 

0.006 

26 Rack Sulfamate (306A) Yes (35) 

No Air High 

 0.031 0.061 0.053 

27 Woods Strike (Rack) No (73) No No 28 Woods Strike (Rack) Yes (30s) Yes 7 Woods Strike (Rack) No (61) Yes No Air High 

 0.614 

 0.129 

 0.063 

0.282 

0.162 

0.081 

0.515 

0.252 

0.236 

24 Woods Strike (Rack) Yes (30s) 29 Woods Strike (Rack) (306A) Yes (40-50s) No 

No 

NA 

NA 

NA High 

High 

High 

 0.048 

0.400 

0.077 

0.165 

0.071 

0.218 

* Phase 1 NA High ** The units for the surface tension value in the parenthesis is dynes/c Yes m NA High *** Absolutely no barrel transfer during testing 

TABLE 3 

Summary of Nickel Emissions Obtained from Phase 1 and Phase 2 Stack Testing 

15
Table 4 

Comparison of Nickel Emissions (Air Agitation versus Eductors)

Process: Air Agitation Eductors 

Electroless Nickel 

(No Mesh Pad) 

6 vs 5 

0.124 

0.313 

0.505 

0.314 

0.142 

0.192 

0.111 

0.148 

Electroless Nickel 

(Mesh Pad) 

3 vs 4 

0.011 

0.006 

0.005 

0.007 

0.024 

0.012 

0.004 

0.013 

Rack Watts 

(No Mesh Pad, Wetting Agent) 

8 vs 9 

0.048 

0.044 

0.032 

0.041 

0.016 

0.027 

0.028 

0.024 

Rack Watts 

(Mesh Pad, No Wetting Agent) 

11 vs 10 

0.057 

0.012 

0.005 

0.025 

0.043 

0.003 

0.016 

0.021 

Rack Watts 

(Mesh Pad, Wetting Agent) 

14 vs 13 

0.003 

0.004 

0.003/0.037/0.008 

0.011 

0.015 

NA 

NA 

0.015 

Rack Sulfamate 

(No Mesh Pad, Wetting Agent) 

22 vs 23 

0.022 

0.011 

0.010 

0.014 

0.043 

0.003 

0.016 

0.017 

Results reported in mg/dscm 

16
Table 5 

Effects of Wetting Agents on Nickel Emissions

Process: No Wetter Wetter 

Rack Watts 

(No Mesh Pad, Air) 

12 vs 8 

0.051 

0.133 

0.056 

0.080 

0.048 

0.044 

0.032 

0.041 

Rack Watts 

(Mesh Pad, Eductor) 

10 vs 13 

0.043 

0.003 

0.016 

0.021 

0.015 

NA 

NA 

0.015 

Rack Watts 

(Mesh Pad, Air) 

11 vs 14 

0.057 

0.012 

0.005 

0.025 

0.003 

0.004 

0.003/0.037/0.008 

0.011 

Barrel Watts 

(No Mesh Pad) 

17 vs 16 

0.975 

1.495 

0.921 

1.130 

0.080 

0.061 

0.118 

0.086 

Barrel Watts 

(Mesh Pad) 

18 vs 20 

0.009 

<0.005 

0.023 

0.012 

0.009 

0.004 

0.012 

0.008 

Barrel Watts 

(No Mesh Pad, No Transfer) 

19 vs 21 

0.056 

0.019 

0.228 

0.101 

0.023 

0.007 

0.009 

0.013 

Wood Strike 

(No Mesh Pad) 

27 vs 28 

0.614 

0.252 

0.515 

0.470 

0.129 

0.162 

0.252 

0.181 

Wood Strike 

(Mesh Pad) 

7 vs 24 

0.063 (0.089)* 

0.081 (0.159)* 

0.236 

0.127 (0.161)* 

0.048 

0.047 

0.071 

0.065 

Results reported in mg/dscm 

* Results adjusted to compensate for cfm difference between Condition 7 and 24 (See Table 

10E) 

17
Table 6 

Effects of Mesh Pads on Nickel Emissions

Process: No Mesh Pad Mesh Pads 

Electroless Nickel 0.142 0.024 

(Eductor) 0.192 0.012 

5 vs 4 0.111 0.004 

0.148 0.013 

Electroless Nickel 0.124 0.011 

(Air) 0.313 0.006 

6 vs 3 0.505 0.005 

0.314 0.007 

Rack Watts 0.051 0.057 

(No Wetting Agent, Air) 0.133 0.012 

12 vs 11 0.056 0.005 

0.080 0.025 

Rack Watts 0.016 0.015 

(Wetting Agent, Eductor) 0.027 NA 

9 vs 13 0.028 NA 

0.024 0.015 

Rack Watts 0.048 0.003 

(Wetting Agent, Air) 0.046 0.004 

8 vs 14 0.032 0.003/0.037/0.008 

0.041 0.011 

Barrel Watts 0.080 0.009 

(Wetting Agent) 0.061 0.004 

16 vs 20 0.118 0.012 

0.086 0.008 

Barrel Watts 0.975 0.009 

(No Wetting Agent) 1.495 <0.005 

17 vs 18 0.921 0.023 

1.130 0.012 

Nickel Sulfamate 0.018 0.004 

(Wetting Agent, Eductor) 0.013 0.006 

23 vs 25 0.020 0.006 

0.017 0.005 

Wood Strike 0.614 0.063 (0.089)* 

(No Wetting Agent) 0.282 0.081 (0.159)* 

27 vs 7 0.515 0.236 

0.470 0.127 (0.161)* 

Wood Strike 0.129 0.048 

(Wetting Agent) 0.162 0.077 

28 vs 24 0.252 0.071 

0.181 0.065 

Results reported in mg/dscm 

* Results adjusted to compensate for cfm difference between Condition 7 and 27 (See Table 10E) 

18
Table 7 

Effects of Barrel Transfer on Nickel Emissions from Watts Nickel Barrel Plating

Process: Barrel Transfer No Barrel Transfer 

Barrel Watts 

(No Wetting Agent) 

17 vs 19 

0.975 

1.495 

0.921 

1.130 

0.056 

0.019 

0.228 

0.101 

Barrel Watts 

(Wetting Agent) 

16 vs 21 

0.080 

0.061 

0.118 

0.086 

0.023 

0.007 

0.009 

0.013 

Results reported in mg/dscm 

19
Table 8 

Effects of Product Loading on Nickel Emissions from Electroless Nickel Plating

Process: Low Tank Loading High Tank Loading 

Electroless Nickel 

(No Mesh Pad) 

1 vs 6 

0.478 (0.290)* 

0.126 (0.078)* 

0.220 (0.135)* 

0.277 (0.167)* 

0.124 

0.313 

0.505 

0.314 

Results reported in mg/dscm 

* Results adjusted to compensate for cfm difference between Condition 1 and 6 (See Table 10A) 

20
Table 9 

Nickel Emissions Method 29 Compared to Method 306A

Process: Method 29 Method 306A 

Electroless Nickel 

(No Mesh Pad) 

1 vs 2 

0.478 

0.126 

0.220 

0.277 

0.080 

0.311 

0.381 

0.251 

Rack Watts 

(Wetting Agent, Mesh Pad, Air) 

14 vs 15 0.

0.003 

0.004 

003/0.037/0.008 

0.011 

0.014 

0.008 

0.012 

0.011 

Rack Sulfamate 

(Wetting Agent, No Mesh Pad) 

22 vs 26 

0.022 

0.011 

0.010 

0.014 

0.031 

0.061 

0.053 

0.048 

Wood’s Strike 

(Wetting Agent, No Mesh Pad) 

28 vs 29 

0.129 

0.162 

0.252 

0.181 

0.400 

0.165 

0.218 

0.216 

Results reported in mg/dscm 

21
Table 10A. Operating Parameters Observed During Stack Testing of Electroless N

Surface 

Tension 

Nickel Content 

(oz/gal) 

Time Actual 

Plating (min)* 

# of 

Parts 

Freeboard 

Height (in)** 

Average Surface Vent

Area Plated (ft2) (cf

Condition 1, Run #1*** 35.0 0.77 30 88 4 25.7 1,Condition 1, Run #2*** 35.0 0.77 12 40 3 5.56 1,Condition 1, Run #3*** 35.0 0.77 12 166 3 23.0 1,Condition 2, Run #1*** 39.1 0.85 90 3 3 0.52 NCondition 2, Run #2*** 39.1 0.85 60 1080 4 13.0 NCondition 2, Run #3*** 39.1 0.85 0 0 4 0 NCondition 3, Run #1 68.7 0.81 115 72-416 8 5.8-22.3 1,Condition 3, Run #2 68.7 0.81 115 108-126 8 27-31.5 1,Condition 3, Run #3 68.7 0.81 105 1-126 8 12-31.5 1,Condition 4, Run #1 68.7 0.81 120 2,400 8 17.7 1,

(barrel) 

Condition 4, Run #2 68.7 0.81 120 2,400 8 17.7 2,

(barrel) 

Condition 4, Run #3 68.7 0.81 120 2,400 8 17.7 2,

(barrel) 

Condition 5, Run #1 68.7 0.81 120 1  8 12.0 2,Condition 5, Run #2 68.7 0.81 120 1** ** 8 12.0 2,Condition 5, Run #3 68.7 0.81 120 1  8 12.0 2,Condition 6, Run #1 68.7 0.81 114 15-100 8 3-16 2,Condition 6, Run #2 68.7 0.81 120 1** ** 8 12.0 1,Condition 6, Run #3 68.7 0.81 120 1**** 8 12.0 1,

* Out of 120 minute testing period ** Measured from vent to solution level (or foam blanket level, if applicable) *** Phase 1 Testing ****1 Dummy Part 

22
Table 10B. Operating Parameters Observed During Stack Testing of Rack Watts Nickel P

Current Density Time Actual Surface Freeboard 

Amps (Amps/ft2) Plating (min)* Tension*** Height (in)** 

Ave Surface 

Area Plated (ft2) 

Nickel

 Content Ve

Condition 8, Run #1  295 42.9 100 38 9-10.5 7.0 10.9 Condition 8, Run #2** ** 300 42.9 100 38 9.5-10.5 7.0 10.9 

Condition 8, Run #3  300 42.1 100 38 9.5 7.0 10.9 Condition 9, Run #1** ** 288 41.1 100 38 9.5 7.0 10.9 Condition 9, Run #2  280 39.4 100 38 9.5 7.0 10.9 Condition 9, Run #3** ** 276 40.0 100 38 9.5 7.0 10.9 Condition 10, Run #1 210 20-26 88 58 9 8.0-10.5 9.4 Condition 10, Run #2 210 20-45 84 58 9 4.5-10.5 9.4 

Condition 10, Run #3 210 30 86 58 9 7.0 9.4 Condition 11, Run #1 230 28.8 100 57 9 8.0 8.2 Condition 11, Run #2 210 20.0 100 57 9 10.5 8.2 Condition 11, Run #3 210 20-26 88 57 6 8.0-10.5 8.2 Condition 12, Run #1 240 25.7 109 57 9 9.3 8.2 Condition 12, Run #2 240 25.7 105 57 9 9.3 8.2 

Condition 12, Run #3 180 95 57 9 8.2 Condition 13, Run #1 130 18.6 114 42 9 7.0 9.6 Condition 14, Run #4 130 18.6 101 42 9 7.0 9.6 Condition 14, Run #5 130-180 100 42 9 9.6 Condition 14, Run #1 125-200 17-20 105 37 9 7.4-11.7 11.4 Condition 14, Run #2 120-200 17-20 96 37 9 6-11.7 11.4 

Condition 14, Run #3 0 0 0 37 9 0 11.4 Condition 15, Run #1 200 17 98 37 9 11.7 11.4 Condition 15, Run #2 200-240 17-20 92 37 9 11.7-12.0 11.4 Condition 15, Run #3 120-240 20-30 96 37 9 4.0-12.0 11.4 

* Out of 120 minute testing period ** Measured from vent to solution level (or foam blanket level, if applicable) *** dynes/cm measured with tensiometer. **** Phase 1 Testing 

23
Table 10C. Operating Parameters Observed During Stack Testing of Barrel Watts Nickel 

Surface Current Density Amps Time Actual # of 

Tension (Amps/ft2) Plating (min)* Barrels*** 

Freeboard 

Height (in)** 

Ave Surface 

Area Plated (ft2) 

Nick

Cont

Condition 16, Run #1  34 3.35-3.78 480-540 110 3 5 143 8.4 Condition 16, Run #2** ** 34 3.50-3.72 500-560 105 3 5 143 8.4 Condition 16, Run #3  34 3.50-3.72 500-560 107 2 5 143 8.4 Condition 17, Run #1** ** 57 1.82 700 117 2 8.0 384 9.8 Condition 17, Run #2  57 1.82 700 114 3 8.5 384 9.8 

Condition 17, Run #3** ** 57 1.82-2.46 600-700 113 3 9 244-384 9.8 Condition 18, Run #1 68 5.28-7.46 300-400 110 4 8 40-76 8.3 Condition 18, Run #2 68 5.28 400 118 3 8 76 8.3 Condition 18, Run #3 68 5.28 400 118 3 8 76 8.3 Condition 19, Run #1 68 5.28 400 120 1 8 76 8.3 Condition 19, Run #2 68 5.28 400 120 1 8 76 8.3 Condition 19, Run #3 68 5.28 400 120 1 8 76 8.3 

Condition 20, Run #1 31 1.56-16.9 100-600 88 5 8 36-322 8.4 Condition 20, Run #2 31 5.28 400 106 3 8 76 8.4 Condition 20, Run #3 31 5.28 400 116 3 8 76 8.4 Condition 21, Run #1 31 5.28 400 120 1 8 76 8.4 Condition 21, Run #2 31 5.28 400 120 1 8 76 8.4 Condition 21, Run #3 31 5.28 400 120 1 8 76 8.4 

* Out of 120 minute testing period ** Measured from vent to solution level (or foam blanket level, if applicable) *** Number of barrels plated during testing time period.   Phase 1 Testing 

24
Table 10D. Operating Parameters Observed During Stack Testing for Rack Nickel Sulfama

Current Density 

(Amps/ft2) 

Time Actual 

Plating (min) 

Surface 

Tension** * 

Freeboard 

Height (in)** 

 Average Surface 

Area Plated (ft2) 

Nickel

Content 

Ventilatio

Condition 22, Run #1 39.6-61.9 96 39 8 14.7-26.6 8.59 Condition 22, Run #2 31.9-75.5 96 39 9 5.56-26.6 8.59 

Condition 22, Run #3 27.5-66.9 96 39 9 14.7-26.4 8.57 Condition 23, Run #1 35.1-61.9 98 44 9 9.4-24.0 7.73 Condition 23, Run #2 34.8-56.3 90 44 9 17.8-23.0 7.73 

Condition 23, Run #3 37.2-61.9 64 44 9 9.4-24.50 7.73 Condition 25, Run #1 26.4-59.7 75 44 9 9.40-22.7 7.73 Condition 25, Run #2 27.7-47.7 45 44 9 9.40-24.0 7.73 

Condition 25, Run #3 41.7 99 44 9 24.0 7.73 Condition 26, Run #1 35-61.9 88 35 9 9.4-26.6 8.51 Condition 26, Run #2 16.9-49.5 77 35 9 9.4-24.0 8.51 Condition 26, Run #3 25-61.9 85 35 9 17.8-26.6 8.51 

* Out of 120 minute testing period ** Measured from vent to solution level (or foam blanket level, if applicable) *** dynes/cm measured with tensiometer. 

25
Table 10E. Operating Parameters Observed During Stack Testing for Wood’s Nickel Strik

Current Density 

(Amps/ft2) 

Time Actual 

Plating (min)* 

Surface 

Tension*** 

Freeboard 

Height (in)** 

 Ave Surface

Area Plated (ft2) Nickel Content 

Ventil

Condition 7, Run #1 25.6 120 61 8.5 12.5 3.17 Condition 7, Run #2 25.6 120 61 8.5 12.5 3.17 

Condition 7, Run #3 25.6 120 61 8.5 12.5 3.17 Condition 24, Run #1 25.6 120 37-40 8.5 12.5 3.34 Condition 24, Run #2 25.6 120 37-40 8.5 12.5 3.34 Condition 24, Run #3 25.6 120 37-40 8.5 12.5 3.34 Condition 27, Run #1 4.9-25.6 119 73 8.5 12.5-51.3 2.43 Condition 27, Run #2 25.6 120 73 8.5 12.5 2.43 

Condition 27, Run #3 25.6 120 73 8.5 12.5 2.43 Condition 28, Run #1 25.6 120 37-40 8.5 12.5 1.62 Condition 28, Run #2 25.6 120 37-40 8.5 12.5 1.62 Condition 28, Run #3 25.6 120 37-40 8.5 12.5 1.62 Condition 29, Run #1 25.6 120 40-50 8.5 12.5 1.62 Condition 29, Run #2 25.6 120 40-50 8.5 12.5 1.62 Condition 29, Run #3 25.6 120 40-50 8.5 12.5 1.61 

* Out of 120 minute testing period ** Measured from vent to solution level (or foam blanket level, if applicable) *** dynes/cm measured with tensiometer. 

26
Table 11. Ambient Air Nickel Concentrations 

OSHA Nickel 

Nickel Concentration 

Ambient Air (mg/m3)

Concentration Adequate 

 Limit (mg/m3) Ventilation 

Condition 3 (Reliable – East) 0.0062 1.00 Yes 

Condition 3 (Reliable – West) 0.0053 1.00 Yes 

Condition 4 (Reliable – East) 0.0060 1.00 Yes 

Condition 4 (Reliable – West) 0.0053 1.00 Yes 

Condition 5 (Reliable – East) 0.0069 1.00 Yes 

Condition 5 (Reliable – West) 0.0063 1.00 Yes 

Condition 6 (Reliable – East) 0.0156 1.00 Yes 

Condition 6 (Reliable – West) 0.0122 1.00 Yes 

Condition 10 (ABQC – East) 0.0065 1.00 Yes 

Condition 10 (ABQC – West) 0.0012 1.00 Yes 

Condition 11 (ABQC – East) 0.0199 1.00 Yes 

Condition 11 (ABQC – West) 0.0029 1.00 Yes 

Condition 12 (ABQC – East) 0.0657 1.00 Yes 

Condition 12 (ABQC – West) 0.0074 1.00 Yes 

Condition 13 (ABQC – East) 0.0694 1.00 Yes 

Condition 13 (ABQC – West) 0.0047 1.00 Yes 

Condition 14 (ABQC – East) 0.0062 1.00 Yes 

Condition 14 (ABQC – West) 0.0043 1.00 Yes 

Condition 15 (ABQC – East) 0.0041 1.00 Yes 

Condition 15 (ABQC – West) 0.0013 1.00 Yes 

Condition 18 (Artistic – North) 0.0025 1.00 Yes 

Condition 18 (Artistic – South) 0.0031 1.00 Yes 

Condition 19 (Artistic – North) 0.0004 1.00 Yes 

Condition 19 (Artistic – South) 0.0004 1.00 Yes 

Condition 20 (Artistic – North) 0.0011 1.00 Yes 

Condition 20 (Artistic – South) 0.0009 1.00 Yes 

27
Table XI. Ambient Air Nickel Concentrations (Cont.) 

OSHA Nickel 

Nickel Concentration Concentration Adequate 

Ambient Air (mg/m3) Limit (mg/m3) Ventilation 

Condition 21 (Artistic – North) 0.0008 1.00 Yes 

Condition 21 (Artistic – South) 0.0008 1.00 Yes 

Condition 22 (Elite – North) 0.0026 1.00 Yes 

Condition 22 (Elite – South) 0.0046 1.00 Yes 

Condition 23 (Elite – North) 0.0036 1.00 Yes 

Condition 23 (Elite – South) 0.0089 1.00 Yes 

Condition 25 (Elite – North) 0.0014 1.00 Yes 

Condition 25 (Elite – South) 0.0017 1.00 Yes 

Condition 26 (Elite – North) 0.0064 1.00 Yes 

Condition 26 (Elite – South) 0.0064 1.00 Yes 

Condition 7 (Artistic – East) 0.1259 1.00 Yes 

Condition 7 (Artistic – West) 0.0139 1.00 Yes 

Condition 24 (Artistic – East) 0.0676 1.00 Yes 

Condition 24 (Artistic – West) 0.0120 1.00 Yes 

Condition 27 (Artistic – East) 0.3085 1.00 Yes 

Condition 27 (Artistic – West) 0.0398 1.00 Yes 

Condition 28 (Artistic – East) 0.1831 1.00 Yes 

Condition 28 (Artistic – West) 0.0054 1.00 Yes 

Condition 29 (Artistic – East) 0.2119 1.00 Yes 

Condition 29 (Artistic – West) 0.0133 1.00 Yes 

28
Section 6.0 DISCUSSION OF RESULTS 

Table 3 

The results presented in Table 1 summarize the nickel emission data obtained from both Phase 1 

and Phase 2 of this project. The results from each of the three individual test runs along with the 

average of the three tests runs from each condition tested are reported in the table. All of the 

results were obtained using Method 29 stack testing except those identified as Method 306A. 

Based on these results, it is apparent that the typically operated Rack Watts Nickel and the Rack 

Nickel Sulfamate processes (wetting agent, no mesh pads, air agitation) emit very little nickel; 

less than 0.05 mg/dscm. These concentrations are not much higher than the MACT hexavalent 

chromium limits that are based on the use of expensive composite mesh pad systems to reduce 

the chromium emissions. These results were expected due to the high efficiency of the Watts 

Nickel and Nickel Sulfamate plating process (very little gassing). Furthermore, the Rack Watts 

Nickel and the Rack Nickel Sulfamate solutions are typically operated with some kind of wetting 

agent employed in order to maintain the quality of the plating (reduce pitting, etc.). Therefore, 

platers need to add wetting agents to these solutions for quality purposes; the pollution control 

effect is a secondary benefit. 

Nickel emissions being emitted from uncontrolled Wood’s Nickel Strike, Barrel Nickel, and 

Electroless Nickel plating processes vary from 0.101 mg/dscm to 1.130 mg/dscm. 

“Uncontrolled” is defined as no wetting agent, eductor system or mesh pads added to the 

process. None of these solutions require a wetting agent for quality purposes. Therefore, these 

processes typically operate without one. Other reasons why the uncontrolled emissions are high 

include: 

- The Wood’s Nickel Strike process is intentionally very inefficient which 

causes significant gassing. 

- Barrel Nickel plating has many mechanical/physical effects that increase 

nickel emissions (see Discussion of Table VII). 

- The Electroless Nickel plating process is operated at very high 

temperatures, has a very high air agitation rate, and produces a significant 

amount of hydrogen gas as a by-product. 

Paired Wilcoxon Signed-Rank tests were conducted to evaluate the effect of employing an 

eductor system, wetting agent or simple mesh pads at the exhaust hood. The paired Wilcoxon 

Signed Rank Test (WSRT) is a non-parametric test that evaluates the median difference between 

paired samples. 

The results of the eductor system versus air agitation comparison was inconclusive (test statistic 

value = 0.5256, p-value=0.5992, n=6). There was insufficient information to conclude that 

nickel emissions were reduced by the addition of an eductor system. The results of the wetting 

29
0 0. 0 2. 0 4. 0 6. 0 8. 1 0.

N ci kel Em si s oi ns

Wetting Agent No Wetting Agent 

Nickel Emissions 

0.0 0.05 0.10 0.15 0.20 0.25 0.30 

Eductor System Air Agitation 

Agent. 

agent versus no wetting agent comparison was statistically significant (test statistic value = 36, pvalue = 0.0078, n = 8). Nickel emissions were reduced by the addition of a wetting agent. The 

results of the mesh pad versus no mesh pad comparison were statistically significant (test statistic 

value = 55, p-value = 0.002, n = 10. Nickel emissions were reduced by the addition of simple 

mesh pads at the exhaust hood. The boxplots in Figure 1, 2, and 3, confirm the conclusions of the 

inferential tests. In each case, employing an operating parameter to reduce nickel emissions 

consistently reduced between process variability, but only in the case of employing a wetting 

agent or installing a mesh pad installed at the box hood was median nickel emissions reduced. 

The investigation did not evaluate the interaction between these operating parameters, therefore 

no conclusions can be made regarding cumulative effect of employing more than one of these 

operating parameters. 

Figure 1. Box plots of Nickel Emissions for Eductor System versus Air Agitation. 

Figure 2. Box plots of Nickel Emissions for Wetting Agent versus No Wetting 

30
Ni i i c m ss s on

0 0 0 0 0 0 0

kel E

. . . . . . 2 4 6 8 1

Mesh Pads No Mesh Pads 

Figure 3. Box plots of Nickel Emissions for Mesh Pads and No Mesh Pads.

Tables 4 through 9 present the results summarized in Table 3, in a comparison manner that 

illustrate the effects on nickel emissions of the operating conditions identified by this project (i.e. 

the effects of wetting agents, the effects of mesh pads, eductors vs. air agitation, etc.). 

The nickel emissions from the rack Watts nickel process operated with a wetting agent, a mesh 

pad, and an eductor system (Condition 13) was only tested for one two-hour test run due to 

quality issues caused by the eductor system. The eductor system caused dullness and pitting in 

the nickel finish in many of the parts that were plated in the nickel tank. Since most of the 

testing conducted in this project was conducted on actual plating processes in operation, the 

quality of the plated parts took precedence over the stack testing. When modifications to the 

operating parameters of the nickel process (temp, current density, etc,) and to the eductor system 

itself would not alleviate the plating problems, the eductor system was decommissioned and 

replaced with the air agitation system. The two remaining test runs during that day were 

completed with the air agitation system in operation resulting in a total of five test runs 

conducted on a rack Watts nickel process operated with a wetting agent, a mesh pad, and an air 

agitation system (Condition 14). 

It was later determined that the plating problems were caused by iron contamination in the nickel 

solution that was directed at the parts by the eductors and then becoming embedded in the plating 

finish causing the pitting and the dullness. It is anticipated that once the iron contamination is 

removed (via filtration), the eductor system can be used in the process without causing quality 

problems; as others have used eductors on Watt’s Nickel very successfully. 

As with the Phase 1 testing, there was a comparably large difference in nickel emissions 

measured within each of the three individual test runs of a condition tested. For example, the 

nickel emission concentrations for the three tests runs on the Electroless Nickel process operated 

with air agitation (Condition 6) were measured to be 0.124, 0.313, and 0.505 mg/dscm. The 

main reason for these differences within individual test runs may be the fact that operating 

31
parameters changed slightly from test run to test run. Because these tests were conducted, for the 

most part, on nickel plating processes plating actual production parts, keeping all the operating 

parameters constant during all three test runs was not possible. Attempts were made, however, 

to minimize the operating parameter fluctuations where possible. Because of these differences 

within the individual test runs, the average of the three were taken and also reported. 

Table 4 

Based on the results of this study and illustrated in Table 4, when the nickel emissions are 

uncontrolled, the data shows nickel emissions are reduced by 53% when eductors are used for 

agitation in place of air (See Condition 5 versus 6). When the nickel emissions are low, whether 

it is due to the nickel plating process itself having low emissions (as is the case with nickel 

sulfamate) or the fact that the emissions are reduced by some other means (i.e., mesh pad), the 

effects of using eductors instead of air agitation are negligible with an average reduction of 8% 

(See Conditions 3 versus 4, 13 versus 14, and 22 versus 23). In fact, in many of these cases, the 

nickel emissions measured with the eductors in operation were actually slightly higher than those 

measured with the air agitation system operating. That said, we do not believe that using the 

eductors actually increased the emissions; simply that eductors have very little effect on the 

nickel emission when the emissions are low to begin with. These unexpected results obtained 

when emissions are low are probably due to the inherent error in the Method 29 procedure or the 

fact that, in some of the cases, the surface tension of the plating solution was slightly higher 

when the eductors were tested than when the air agitation system was tested. For example, the 

surface tension of the Watts Nickel solution when the eductors were tested was 42 dynes/cm 

while the surface tension of the same solution when the air was operating was 37 dynes/cm. 

Similarly, the surface tension of the Nickel Sulfamate solution when the eductors were tested 

was 45 dynes per centimeter while the surface tension of the same solution when the air was 

operating was 39 dynes per centimeter. These small differences in surface tension could have 

masked the emission reduction effects of the eductors because it is believed (and validated in this 

study) that nickel emission of a plating solution are related to its surface tension; the emissions 

increase as the surface tension increases. 

Maintaining a constant surface tension within a plating solution is difficult because only a small 

amount of wetting agent is needed to reduce the surface tension from about 70 to 40 dynes/cm. 

To raise a surface tension in a solution to a specified level requires considerable time to allow the 

surface tension to rise naturally or complicated carbon treatment. 

Table 5 

Based on the results of this study and illustrated in Table 5, the use of wetting agents to reduce 

the surface tension of a nickel plating solution significantly reduces the nickel emissions from 

that process an average of 72% from uncontrolled tanks and an average of 42% for tanks 

controlled with mesh pads. In all eight comparison studies involving the use of wetting agents 

and encompassing Rack Watts Nickel, Barrel Watts Nickel, and Wood’s Nickel Strike plating 

solutions, the nickel emissions measured with the wetting agent were 29% to 92% lower than the 

nickel emissions measured without the wetting agent. 

32
Several chemical suppliers were contacted to determine the availability of a wetting agent 

specifically made for a Wood’s nickel strike solution. None of these chemical manufacturers 

could provide one nor did they believe one was developed yet. Therefore, a wetting agent that 

was typically used in a Watts Nickel solution was used instead. Initial tests proved that this 

wetting agent was successful in reducing the surface tension of the Wood’s nickel strike solution 

from 70 dynes/cm to 38 dynes/cm. However, it was later discovered that the acidic nature of the 

Wood’s solution destroyed the wetting agent relatively quickly (within two to three days). 

Moreover, the resultant decomposition products of the wetting agent formed a film on the plating 

solution which adversely affected plating adhesion. 

In Table 5, there are two results reported for some of the test runs of Condition 7. The results in 

the parenthesis are results that have been modified to account for the air ventilation rate 

fluctuations that occurred during the Condition 7 testing. For all the other Wood’s Nickel Strike 

test runs, the ventilation rate measured during the testing was 818 to 892 cfm. The ventilation 

rate for the three Condition 7 tests runs was measured to be 1155 cfm, 1610 cfm, and 818 cfm 

respectively. The blower for the Wood’s Nickel Strike ventilation system is a variable speed 

blower. It is believed that the speed was switched to “high” sometime during the first test run and 

then switched back to “low” after the second test run. To compensate for this dilution effect and 

to provide a viable comparison, the nickel emissions from the first two test runs of Condition 7 

were mathematically revised to reflect a ventilation rate of 818 cfm. 

Table 6 

Based on the results of this study and illustrated in Table 6, the use of simple mesh pads to 

capture nickel emissions in the vent reduces the nickel emissions from that process. In all ten 

comparison studies involving the use of mesh pads and encompassing Rack Watts Nickel, Barrel 

Watts Nickel, Wood’s Nickel Strike, Nickel Sulfamate, and Electroless Nickel plating solutions, 

the nickel emissions measured with the mesh pad in place were significantly lower than the 

nickel emissions measured without the mesh pad by an average of 88% for both controlled and 

uncontrolled conditions.. 

The mesh pad, based on this study, was the most efficient in reducing nickel emissions; 

outperforming the wetting agents and the eductor system as shown in Table 12.. Besides 

providing better reduction efficiency, simple mesh pads are less expensive to purchase than the 

eductor system and less expensive to use than the wetting agents. Moreover, mesh pads are 

totally external to plating solution system. When contemplating using a wetting agent or an 

eductor system, one needs to consider the effects of these items on the plating quality because 

they are placed in the plating tank. The mesh pad does not affect the plating at all since it is 

installed in the ventilation system. 

33
Table 12. Comparison of Nickel Emission Reductions 

Condition %Reduction of Nickel Emissions 

Mesh Pads Wetting Agent Eductors 

Uncontrolled 

Tank 

83% 69% 53% 

Partially 

Controlled Tank 

69% 45% 8% 

The composite mesh pads used in this project were supplied by Chicago Plastics and were easily 

inserted in the face of the exhaust hoods; although some exhausts hoods had to be modified in 

order to accommodate the composite mesh pads (See photos in Appendix C). The composite 

mesh pads are constructed of intertwined polypropylene threads and are approximately three (3) 

inches thick. As stated above, these composite mesh pads were easily placed in the face of the 

exhaust hood or directly in the exhaust duct (as was the case with Elite Finishing) and are 

designed to capture mists and large particulates (greater than 8 microns). 

Table 7 

The stack testing results presented in Table 7 suggests that the majority of the nickel that is 

emitted from barrel nickel operations is due to mechanical/physical sources such as splashing 

produced during entry of the barrel into the tank, the large amounts of liquid leaving the barrel 

during removal from the tank, splashing from filter pumps, etc and not from the electrolysis 

involved in plating. These results are consistent in what was suggested in the Final Report for 

the Phase 1 testing. 

Table 8 

Based on the results presented in Table 8, it appears that the chemical reaction involved in the 

electroless plating process does increase the nickel emissions from an electroless nickel process. 

In the Final Report for Phase 1 of this project, it was suggested that the majority of the emissions 

from an electroless nickel plating process were due to the high temperature of the electroless 

nickel plating solution and the violent air agitation required in the process and that the amount of 

parts (or surface area of the parts) had little affect on the nickel emissions. In the Phase 1 testing 

(Condition 1), parts were being plated for only 12-30 minutes of the test run time (120 minutes). 

In Phase 2 (Condition 6), however, parts were being plated for 114 to 120 minutes of the 120 

minute test run. As illustrated in Table 8, the emissions measured in Phase 2 with the high tank 

loading were higher than those measured during Phase 1 with the low tank loading. However, in 

the year that elapsed between Phase 1 and Phase 2, the EN testing site switched EN solution 

suppliers. The EN solution that was being used during Phase 1 of the study had a wetting agent 

incorporated into the chemistry while the EN solution that was being used during Phase 2 did 

not. Consequently, the surface tension of the EN solution in process during Phase 1 was about 

30 dynes/cm lower than the surface tension of the EN solution that was in process during Phase 

2. Therefore, it is inconclusive as to the cause of the increased emissions observed during 

34
Condition 6 as compared to Condition 1 (increased parts loading or increased surface tension, or 

a combination of the two). 

Part of the Phase 2 testing was to observe the effects of a mesh pad on the nickel emissions from 

the electroless nickel plating process. In order to accomplish this goal, the ventilation system for 

the electroless nickel tank had to be modified to accept a mesh pad. The modification to the 

ventilation system increased the ventilation flow rate. The ventilation rate during Phase 1 was 

1214 to 1240 cfm while the ventilation rate for Phase 2 was 1860 to 2039 cfm. Therefore, to 

compensate for this dilution effect and to provide a viable comparison, the nickel emissions from 

the test runs of Condition 1 were mathematically revised to reflect a ventilation rate of 2000 cfm. 

The modified results are listed in parenthesis in Table 8. 

Table 9 

The results presented in Table 9 indicate that, although the individual test runs were not 

consistent, the average of the three runs using Method 29 were within 10% of the average of the 

three runs using Method 306A for the Electroless Nickel, Watts Nickel and Wood’s Nickel 

Strike processes. For the Nickel Sulfamate process, the emissions measured by Method 306A 

were actually higher than those measured by Method 29. The inconsistency within the three 

individual test runs and the test runs on the Nickel Sulfamate process may have been due to the 

changes in operating parameters during the individual test runs. Based on this testing, we 

believe that Method 306A is a viable alternative to Method 29 for measuring nickel emissions. 

However, we believe more testing is required. 

In order to validate Method 306A as a viable alternative, a non-production process should be 

tested in order to have absolute control over all the operating parameters to ensure that they are 

constant and identical during both the Method 29 and Method 306A testing. When testing 

production processes, the operating parameters change slightly from test run to test run based on 

the production needs. Another option would be to test a production process using Method 29 

and Method 306A simultaneously. 

The emissions from the Woods Nickel Strike process measured with Method 306A were higher 

than the emissions measured with Method 29. Both of these tests were conducted with wetting 

agent in the Woods Nickel Strike solution. The wetting agent was added in the morning of the 

first day. Method 29 was conducted on the first day while Method 306A was conducted on the 

second day. As discussed earlier, it was discovered that the acidic nature of the Woods Strike 

solution destroyed the wetting agent relatively quickly. Analysis on the first day using a 

stalagmometer indicated that the surface tension was approximately 37 dynes/cm. Analysis of 

the Woods Nickel Strike solution three days later using a tensiometer indicated that the surface 

tension was 59 dynes/cm. Therefore, the surface tension on the second day (Method 306A) may 

have been higher than that on the first day (Method 29); possibly in the 40-50 dynes/cm range. 

This discovery may explain why the Method 306A testing measured higher emissions. 

35
Tables 10A through 10E 

The purpose of Tables 10A through 10E is to summarize the working parameters observed and 

recorded during the testing for all of the conditions tested. As stated before, most of the testing 

was conducting during actual processing. Therefore, many of the operating parameters did not 

remain constant during all of the individual test runs within a condition. By comparing the 

operating parameters from one test run to another, one may be able to explain why there was a 

difference in nickel emissions measured from one test one to another. 

Table 11 

The results presented in Table 11 illustrate that the ventilation systems of all the nickel plating 

processes were operating efficiently because the nickel concentrations in the ambient air near the 

nickel plating tanks at the times of the testing were significantly below the OSHA eight hour, 

time weighted average permissible exposure limit for nickel. This criteria was set-up prior to 

testing in order to ensure that the ventilation systems were capturing the majority of nickel 

emissions from the plating processes. 

QA/QC Summary 

The data generated has been evaluated in terms of quality objectives for precision, accuracy, 

completeness, representativeness, and comparability, in accordance with EPA Methods 29 and 

306A and OSHA Method ID-121. 

Prior to analyses, demonstration of method performance and analyst capability was verified and 

documented through various studies as MDL, LDR, QCS, DOC, and Performance Evaluation 

Samples. The appropriate blanks (CCB and LRB), spikes (LFM and LFM dups), and standards 

(QCS, CCV, LFB) were incorporated into the analytical runs as is required by EPA Methods 29 

and 306A and OSHA Method ID-121. These QC samples were evaluated to meet acceptable 

criteria limits, as determined by the procedures and control charts. In order to maintain 

consistency in applying the QC data, the “QA/QC Worksheet” was generated to condense the 

QC values, limits, and qualifiers, if any. These worksheets are included in Appendices E and F. 

All data is considered to be of acceptable quality and validity, as determined by the laboratory 

QA Coordinator. 

36
Section 7.0 CONCLUSIONS 

Based on the stack testing results presented in Table 3, the following conclusions regarding 

nickel emissions from nickel plating processes can be made: 

1) Nickel emissions from typically-operated Rack Watts Nickel and Rack Nickel 

Sulfamate tanks (wetting agent, no mesh pad, air agitation) are not very significant 

(<0.05 mg/dscm). 

2) Nickel emissions from uncontrolled (no eductors, mesh pads or wetting agents) and 

vented Electroless Nickel, Barrel Nickel, and Wood’s Nickel Strike plating processes 

are significant (greater then 0.1 mg/dscm), but can be significantly reduced by 49% to 

92%. This can be accomplished by employing eductors, wetting agents, or simple 

mesh pads. 

3) The use of wetting agents in nickel plating processes significantly reduced nickel 

emissions. The use of wetting agents to reduce the surface tension of a nickel plating 

solution reduces the nickel emissions from that process an average of 72% from 

uncontrolled tanks and an average of 42% for tanks controlled with mesh pads. At 

this time, however, there does not seem to be a wetting agent specifically developed 

for the Wood’s nickel strike solution. A Watt’s Nickel wetting agent can be 

successfully used to reduce the surface tension of the Wood’s nickel strike solution. 

However, the acidic nature (at least 10% by volume hydrochloric acid) of the Wood’s 

solution destroys the wetting agent relatively quickly leaving a film on the solution 

surface that greatly affects the plating adhesion. 

4) Nickel emissions were reduced an average of 15% using eductors in lieu of air 

agitation for the various controlled and uncontrolled conditions... 

5) Regardless of type of nickel process, using simple mesh pads to capture splashing and 

misting provides the best reduction of nickel emissions. These reductions averaged 

69% to 89% compared to 8% to 69% for other control methods as shown in Table 12. 

6) Most of the nickel emissions from nickel barrel plating operations are generated from 

mechanical/physical sources such as splashing produced during entry of the barrel 

into the tank, the large amounts of liquid leaving the barrel during removal from the 

tank, splashing from filter pumps, etc. and not from the electrolysis involved in 

plating. 

7) The nickel emissions from an electroless nickel process are generated from both the 

chemical reaction involved in the electroless plating process and the high solution 

temperature and high agitation rate required in the process. 

8) Although the results presented in Table 9 indicate that USEPA Method 306A and 

37
USEPA Method 29 provide similar results when measuring nickel emissions from 

Electroless Nickel, Watts Nickel, and Wood’s nickel strike, further testing needs to be 

conducted on a controlled process or conducted simultaneously to determine whether 

Method 306A truly is an acceptable alternative to Method 29 for measuring nickel 

emissions from nickel plating processes in general. 

Three methods of reducing nickel emissions observed in this study are the use of wetting agents, 

eductors, and simple mesh pads. The implementation of simple mesh pads provide a better 

reduction efficiency, they are cheaper to employ and do not affect the quality of the plating. 

Due to the extreme number of variables involved in plating (tank dimensions, current density, 

temperature, types of parts plated, plating times, chemical differences, etc.), the results presented 

in this report should not be used as absolute for all Watt’s Nickel, Wood’s Nickel Strike, 

Electroless Nickel, etc. processes “across the board” but rather as a relative guide or estimate for 

these processes. In the same manner, one cannot assign actual emission reduction efficiencies 

for wetting agents, eductors, and mesh pads solely on the results of these tests. Instead, it is 

much more accurate to state that these options reduce nickel emissions but the reduction 

percentage from process to process will vary. We base these project limitations or constraints on 

the fact that even though extreme care was given to control the variables within the three tests 

runs of a test condition, the results for each of these test runs did vary more than expected (see 

Table 3). We would expect the results to vary even greater when the variables are not controlled 

or, for example, from one Electroless Nickel tank to another. 

38