WASTE MINIMIZATION STUDIES IN AN ELECTRICAL DEVICES MANUFACTURING

INDUSTRY

by

Hilal YAĞCI

October, 2003

İZMİR

ABSTRACT

In this article, the ISO 14001 Environmental Management System

implementation studies, the waste minimization studies which shows parallel

improvement with ISO 14001 Environmental Management System practices and the

positive reflections of these works on pollution prevention, raw material and natural

resources consumption was explained.

Waste minimization applications are used by companies to increase the

operational efficiency. ISO 14001 Environmental Management System applications

helps to increase the process efficiency and reengineering applications by providing

systematical approach to the waste minimization applications.

ÖZET

Bu makale ile elektrik ekipmanları üreten bir fabrikada yapılan ISO 14001 çevre

yönetim sistemi kurma çalışmaları; ISO 14001 çevre yönetim sisteminin

uygulanması ile paralel doğrultuda gelişen atık minimizasyon çalışmalarının

gelişimi; bu çalışmaların kirliliğin önlenmesi, ham madde ve doğal kaynak

kullanımının azalması üzerindeki olumlu yansımaları gösterilmektedir.

Atık minimizasyon çalışmaları şirketler tarafından operasyonel verimliliğin

artırılması amacıyla kullanılmaktadır. ISO 14001 Çevre Yönetim Sistemi

uygulamaları, atık azaltım çalışmalarına getirdiği sistematik ve geniş kapsamlı

yaklaşımla süreçlerin yeniden incelenmesine ve verimliliklerinin artırılmasına

yardımcı olmaktadır.

1. Introduction

Environmental problems have emerged with the beginning of the industrial

revolution and with the increase of population. By the mid of 1970’s, environmental

problem has joined importance because negative impacts of the economy and rapid

population grow on natural resources.

Nowadays, the countries all over the world are following the technological

developments. They prefer environmental friendly raw materials and production

processes, they evaluate waste minimization techniques for their operations, also

they all implement environmental management systems (BS 7750, EMAS and ISO

14001) to improve their environmental performances, to identify and to control their

environmental aspects at all steps from entering the raw material to final product.

Sustainable development is a requirement to improve the standard of living and

quality of life in developing countries. It is known that the development of waste

minimization techniques and implementation of environmental management systems

are the most important contribution of industries to sustainable development.

Industries can make product life cycle analysis and assessments in existing and new

product designs, production processes and for all activities. Meanwhile they can

identify their environmental aspects and can prevent their negative environmental

impacts.

BS 7750 is the first step of standardisation works for Environmental Management

System in the world. BS7750 was published by the British Standard Institution in

1992. This was a model standard for ISO 14000 series. ISO 14001 is the most widely

accepted international standard .It was published in 1996. BS 7750 was the base for

the European Union’s Eco-Management and Audit program, which is known as

EMAS.

ISO 14001,EMAS and BS 7750 are very similar in their approach. If any

company implement the BS 7750 requirements, it can implement the other two

systems (ISO 14001 and EMAS) with a little effort; they are too similar to each

other, so it is easy to transfer the systems.

ISO 14000 is a new approach to environmental protection view and it is a

systematic strategy to environmental developments.

Environmental issues are a top priority in the world today, and so is completion of

relevant international standardization system. During the Earth Summit in Rio in

1992, the Business Council for Sustainable Development (BCSD) emphasized that

“business and industry need tools to help measure environmental performance, and

develop powerful environmental management techniques” (Dods, 1997).

Up to the end of 2001, at least 36 765 ISO 14000 certificates had been awarded in

112 countries, an increase of 13 868 certificates (+ 60,57%) over the end of

December 2000 when the total stood at 22 897 in 98 countries. This is by far the

highest increase recorded in the seven cycles of the survey in which ISO 14000 has

been included,starting with the results at end December 1995 (ISO, 2001).

Figure 1. Worldwide Total Of ISO 14000 Certificates (ISO, 2001)

Table 1. Europe ISO 14001 Certification Growth (ISO, 2001)

Also these numbers in the world are increasing day by day because of improving

the market share in world market.

In our country, especially in last five years the certificated organization number is

increasing very fastly. It is expected that in our country in 2003, the certification

number reached to 150.

In Izmir, the ISO 14001 certification number is about 15. (EBSO, Chamber of

Aegean Region Industry, 2003) For Turkey, according to only one certification firm

records, the organization number, which has ISO 14001 certification, is 53 (BWQI,

2003).

1.1 Waste Minimization Techniques

Any practice, which reduces the amount of any hazardous substance, pollutant or

contaminant entering the waste stream or otherwise released to the environment

prior recycling, treatment or disposal: and reduces the hazards to public health and

the environment associated with the release of such substances, pollutants or

contaminants (Aldrich, 1996, p.116).

Figure 2. Principles Of Pollution Prevention (Müezzinoglu, 2000)

UN

SAFE

TY

PREF

EREN

CE

SOURCE REDUCTION

ON-SITE RECYCLING

OFF-SITE RECYCLING

TREATMENT

DISPOSAL

Pollution prevention programs help to reach to national environmental targets

and companies has economical and social benefits by applying pollution preventive

actions. Increasing awareness of population for environmental pollutants force to

companies to reduce the toxicity and sheer volume of the waste they generate.

Decreasing wastes ensures upstream benefits because it decreases environmental

damage from raw material extraction and pollutants releasing during the

manufacturing process and during the manufacturing process and during waste

recycling, treatment, and disposal operations. A company can reduce production

costs by reducing waste amounts, it generates productivity. Also, pollution

prevention applications help to improve company’s public image, public health, and

overall environmental benefits.

A pollution prevention project can benefit from water, energy, and material

savings as well as from waste reduction, recycling, and reuse. It may also deliver

substantial benefits from an improved product and company image or from improved

employee health. These benefits remain largely unexamined in environmental

investment decisions. Although they are often difficult to measure, they should be

incorporated into assessment whenever feasible. At the very least, they should be

highlighted for managers after presenting costs that can be the more easily

quantified and allocated.

Intangible benefits may include:

• increased sales due to improved product quality, enhanced company image,

and consumer trust in green products;

• improved supplier-customer relationship;

• reduced health maintenance costs;

• increased productivity due to improved employee relations; and

• improved relationships with regulators (Shen, 1995, p.101).

2. ISO 14001 Environmental Management System Implementation and

Waste Minimization Studies of Factory A

2.1. General look to the Factory A

Factory A is producing low voltage products, low voltage equipments, high

voltage products and high voltage equipments.

Factory A is located in Izmir, established in Kemalpaşa Organized Industrial

District Area and being managed with ISO 9002 quality assurance system since

1994.

There are 300 employees are working permanently and 50 employees are

working as temporarily according to production volume.

Factory A has implemented ISO14001 environmental management system in

2001 and has been certificated on June 2001 by Turkish Standardization Institute.

In Factory A, the total ISO 14001 Environmental Management System

implementation time has taken along eight months. And in Figure 3 you can see the

timing schedule of ISO 14001 Environmental Management System implementation

studies according to ISO 14001 phases.

Figure 3. Time Schedule of ISO 14001 Implementation

Time Schedule Of ISO 14001 Implementation

%4%22

%55

%15 %4

Environmental Policy PlanningImplementation and Operation Checking and Corrective ActionManagement review

Figure 4. Environmental Management System Model (Stapleton & Glover, 2001, p.1)

Planning

• Environmental Aspects • Legal & Other Requirements

• Objectives & Targets • Environmental Management Program

Implementation • Structure & Responsibility

• Training, Awareness, Competence • Communication

• EMS Documentation • Document Control • Operational Control

• Emergency Preparedness / Response

Start

Environmental Policy

Checking / Corrective Action

• Monitoring & Measurement • Nonconformance & Corrective &

Preventive Action • Records

• EMS Audits

Continual Improvement!

Management Review

The environmental management system model in Figure 4, had been implemented in

Factory A. All the steps were adapted and the documentation had been evaluated for every

step. In Table 2 you can see the contents of Environmental Management System Handbook

and main procedures name of Factory A.

Table 2. Contents of Environmental Management System Handbook

Definition ISO 14001 Article Introduction Contents The Summary Of Changes Abbreviations Distribution And Approval List Objective And Practice Area Environmental Management System Organization Environmental Management System Environmental Commitment Environmental Policy 4.2 Environmental Aspects 4.3.1 Legal And Other Requirements 4.3.2 Objectives And Targets 4.3.3 Forming Environmental Register 4.3.3 Environmental Management Program 4.3.4 Structure And Responsibility 4.4.1 Training, Awareness, And Competence 4.4.2 Communication 4.4.3 Environmental Management System Documentation Management And Control

4.4.4, 4.4.5

Operational Control System 4.4.6 Solid Waste Management Procedure 4.4.6 Wastewater Treatment Plants Sludge’s Management Procedure 4.4.6 Wastewater Management Procedure 4.4.6 Air Pollution Control Procedure 4.4.6 Natural Resources Usage Procedure 4.4.6 Hazardous Material And Product Control Procedure 4.4.6 Noise Control Procedure 4.4.6 Drinking Water And Process Water Management Procedure 4.4.6 Supplying And Purchasing Management Procedure 4.4.6 Hazardous Waste Management Procedure 4.4.6 Occupational Safe And Health 4.4.6 Emergency Preparedness And Response Procedure 4.4.7 Wastewater Treatment Plant Emergency Situations Procedure 4.4.7 Monitoring And Measurement 4.5.1 Water Pollution Measurement Principles Procedure 4.5.1 Calibration 4.5.1

Nonconformance And Corrective And Preventive Action 4.5.2 Records 4.5.3 Environmental Management System Audits 4.5.4 Management Review 4.6 Instructions List Forms List

While beginning waste minimization studies, firstly a process flow diagram had been

created which was used as a guide. Then several waste minimization applications had been

evaluated as expressed below.

2.2 Waste Minimization Applications

2.2.1 Source Reduction Applications

2.2.1.1 Modification in Mould of Part A

Net weight of Part A is 4960 grams. While moulding operation, 5902 grams epoxy mix

was injecting to mould and 942 grams scrap was being generated due to leakages and gates.

This value equals to 16 % of total injected raw material. Epoxy leakage sources had been

investigated. After this investigation, it has been understood that these leakages could be

prevented by putting a special seal over the touching points of male and female sides of

mould. It has been decided to do this modification, first one channel was made by grinding in

both side of mould. Later, a special seal has been inserted to these channels. After closing of

all gaps which are situated in touching place of moulds, 570 grams raw material gained. As a

result 60.5% improvement were obtained in scrap weight, totally 9% scrap saving have been

obtained by this modification. Additionally 2 % man power saving gained after this

modification, because no longer there was no need to do extra cleaning works to remove

scraps over the moulded parts.

2.2.1.2 Epoxy Pulp Recovery

First, epoxy mixes are prepared in fix epoxy mixers. Later, mixed pulp transferred from fix

mixers to mobile mixers by flexible tubes and then mixed epoxy pulp is injected trough

flexible tubes from mobile mixers to injection machine. After this loading operation, injection

machines use this epoxy pulp during 1-1.5 hours (usage time depends on injected part’s

weight). But during 1-1.5 hours, remaining pulp’s viscosity which is inside the mixer’s

flexible tube, falling down and pulp became contaminated. Later contaminated epoxy pulps

removed from inside the flexible tube and are separated as scrap, 275 grams contaminated

pulp generated during one loading operation. Approximately 1375 grams virgin epoxy pulp

became scrap due to this reason in a one shift per machine. Production engineer decided to

close the edges of tubes by using special fitting components. Totally, 20.6 kilograms epoxy

pulp gained during one shift and 61.8 kilograms saving obtained per a day. 1856 kilograms

have been obtained by this modification in a month. As a result, 43.7saving have been

obtained in scrap weight and this saving is equal to 5.6% improvement in scrap ratio.

2.2.1.3 Automated Loading System

Quarts come from suppliers with 250 kilograms big bags by truck. Big bags are brought by

crane over the fix mixers tanks, edge of big bag is teared and powder quarts fall down inside

the mixer’s tank. But while powder quarts falling down from big bag to tank, some of powder

quarts run away from tank by air movements. After loading operation, workshop floor is

cleaned. When powder quarts and dusts are mixed in the workshop floor, powder quarts

became scrap. For this reason, powder quarts can not be used again in the process. After

investigation, it is observed that approximately 0.83% powder quarts were missing due to

unprotected loading operation. Later the corrective action decision had been taken by

production team to prevent this leakage, they put this corrective action into annual

environmental program. According to plan one huge silo with 40 tones capacity were

constructed and big bag usage were cancelled. Quarts started to come with in bunker instead

of big bags. Two helical gear mechanisms were established. First helical gear system was for

quarts transferring to bunker to silo, second helical gear system was for loading quarts from

silo to fix mixer tanks. All these operations are in closed area, so that there was no chance for

leakage while transferring the raw material. Before modification quarts leakage was 350

kilograms/month, after modification leakage amount were decreased to 42 kilograms/month.

So, 0.73% saving have been obtained.

2.2.1.4 Renewal Of Old Injection Machinery

Three of injection machines were more than 15 years old and they were causing oil

leakages, bad quality in injection, pressed air leakage and ineffective working. Management

decided to renewal these benches in 2002 and budgeted for 2003 annual environmental

management program. Beginning of 2003 three new PLC controlled injection machines were

ordered and machines were established in the middle of March. After renewal non quality

ratio of these benches were reduced from 12% to 1.7%.

2.2.1.5 Electricity Reduction

There are lots of machinery and equipment in factory A (injection machinery, mixers,

electrical heaters, motors etc.) Related with ISO 14001 Environmental Management System

requirements, it was necessary to follow up of process, measure the results and then define the

indicators after realize the plan of actions to reach the defined targets. For this reason a special

automation system was designed to manage all electrical activities around the factory,

especially in Epoxy casting workshop. This system had advanced software and hardware

based system which allows adjusting, managing, and reporting the lots of electrical

operations. Furthermore this system was integrated with web based programs. By this

integration, it was able to adjust all parameters of main electrical equipment’s functions by

reaching internet. System was adjusting all working parameters of machinery and reporting

the electrical consumption levels and also if any broken happened on the machinery, it was

giving an error message which shows the source of problem, by this system average

maintenance time, scrap ratios were reduced, production quality and productivity, overall

equipment efficiency have been increased.

2.2.1.6 Heat Isolation Plates

In injection machinery, epoxy pulp is injected into mould and cooked inside the mould in

200 ºC during 25-35 minutes (cooking time depends on thickness of part). Cooking

temperature should be same during all operations, otherwise injected pulp can be scrap due to

insufficient heating or over heating. To manage the heat stabilization there are thermocouples

which is inserted inside the mould. Moulds are connected to injection machine body by

special connecting parts but heat transfer realize from mould to machine body. It cause over

electricity consumption. Special heat isolation materials were researched to decrease this

unwanted heat transfer. A special heat isolation plates have been found in Swiss. Heat transfer

coefficient was very low. 30 isolation plates imported from Swiss and then plates were

adapted between mould and machine. After this modification electricity consumption were

started to follow up. Before modification there was 1.6 kWh electricity consumption per 1

kilogram epoxy pulp, after modification electricity consumption per 1 kilogram epoxy pulp

had been decreased to 1.15 kWh, it is equal to 28% electricity saving per kilogram.

2.2.1.7 Improvement of Lighting System

One timer was installed in electricity distribution panel to manage lighting lamps. Timer

was set to close lamps at 07 o’clock in the morning and open the lamps at 08 o’clock pm.

Later one shadow sensor were adapted to system, system became more powerful to manage

the lighting operations. Shadow sensor help to manage the lighting system according to light

flux level. Daylight usage increased by this modification.

2.2.1.8 Reduction of LPG Usage

Workshops are heated by radiant heating system. Three thermostats were added to control

workshop’s ambient temperature. There were two manual controlled heavy doors in

workshop. There were some gaps around the door’s frame which allows air ventilation. It is

decided to replace the existing doors with remote controlled, automated door systems. This

modification was budgeted and put the annual environmental management program and this

modification was realized in 2002. Before modifications, there was 1.3 Lt/m² LPG

consumption, after modification LPG consumption ratio had been decreased to 0.8 Lt/m² and

ambient temperature stabilization were provided by this way.

2.2.1.9 Recovery of Epoxy Scraps

After changing solid waste regulation in 2002, disposal method and place were

researched. First, necessary tests has been done in a cement factory and it was observed that

the burning gases effects of epoxy scraps on the existing ratios of other flue gases were not

critical. After these tests, Factory A agreed with Cement Factory to make disposal the epoxy

scraps in cement factory. Factory A prepared an agreement for disposal firm, according to this

agreement disposal firm started to brake scraps to take the worthy materials which are inside

the scraps (copper, iron, aluminum), later scrap firm transferred the pure epoxy scraps to

cement factory. Cement factory started to use epoxy scrap as fuel by mixing other coals. After

this arrangement 180 kilograms aluminum, 1144 kilograms copper, and 3090 kilograms

epoxy and 287 kilograms iron were recovered during first three months of 2003.

2.2.2 Off Site Recycling Applications

2.2.2.1 Solid Epoxy Wastes

These wastes are segregated in special containers and collected in different areas. Than

they are sold to scrap dealer because these wastes can be used. Scrap dealer breaks the

polymerized epoxy wastes into pieces and segregate the metallic parts. Than they sell these

pieces to cement factories as a fuel for off site recycling.

2.2.2.2 Metal Scraps

Copper, Aluminum, Brass and Iron are the main kinds of metal scraps. These scraps are

collected separately in different containers and sold to a scrap dealer for off site recycling.

2.2.2.3 Waste Oils

Waste oils (generally originated from hydraulic oil leakages) are collected and sold to

licensed firm for off site recycling.

2.2.3 Treatment Applications

2.2.3.1 Domestic Wastewaters

The daily usage sourced domestic wastewater is collected separately by sewer system and

sent to wastewater treatment plant of the factory.

2.2.3.2 Industrial Wastewaters

The process based wastewaters are collected and treated with a separate wastewater

treatment plant, which has a capacity of 10 m3/day.

2.2.4 Disposal Applications

2.2.4.1 Quarts Dusts

The dirty sacks of quarts dusts and quarts dusts on the floor are collected in special containers and sent to incineration plant for disposal.

2.2.4.2 Waste Sludges

The waste sludges generated from treatment applications are collected in special basins for

sludge dewatering.

2.3 Obtained Results

In Factory A, four main performance indicators were defined to measure the effectiveness

of Environmental Management System. These indicators are waste ratios, electricity

consumption/ unit product, LPG consumption / unit product and water consumption / unit

product.

As you can see in Figure 5, the percentage of recycled waste ratio increased from 81% to

86% between 2001 and 2002. Waste segregation applications, employee training and ISO

14001 Environmental Management System implementation studies explain us the reason of

this positive increasing in recycled waste ratio.

Figure 5 Comparison of Waste Ratios

Also we can see the other positive effect on decreasing of hazardous & industrial waste

ratios. After waste minimization applications the hazardous and industrial waste ratio had

been decreased, some of these wastes had been recycled and recycled waste ratio had been

increased by this way. If you look at the domestic waste ratio’s comparison; you will see that

2002 domestic waste ratio is slightly higher than 2001 results. When increasing reasons have

been investigated, it was understood that employee quantity’s increasing in 2002 is the main

reason of increasing in 2002’s domestic waste ratio.

The Figure 6 shows the average electricity consumption per product according to years. In

2001, the average electricity consumption ratio was 90 kWh/Unit Product. As the result of

implemented electricity reduction programs, this ratio decreased to 69 kWh/Unit Product. It

means that 21% saving in electricity consumption.

Comparison of Waste Ratios

0102030405060708090

100

Recycled Wastes Hazardous &Industrial Wastes

Domestic Wastes

Waste Classes

Perc

enta

ges

(%)

2001 2002

Figure 6 Electricity Consumption

As illustrated in Figure 7, you can see the decreasing percentage of LPG consumption.

Before LPG reduction programs in 2001, the average LPG consumption was 6.7 m3/Unit

Product, after LPG reduction programs (heat thermostat implementation, heat isolation,

replacement of old entrance doors with automatic doors, etc.) this ratio became 6.4 m3/Unit

Product.

Figure 7 LPG Consumption

Electricity Consumption

0

20

40

60

80

100

2001 2002

Years

Ave

rage

Con

sum

ptio

n Pe

r Uni

t Pro

duct

(kW

h /

Uni

t

LPG Consumption

6.2

6.3

6.4

6.5

6.6

6.7

6.8

2001 2002

Years

Ave

rage

LPG

Con

sum

ptio

n Pe

r Uni

t Pr

oduc

t (m

3 / U

nit

Prod

uct)

Environmental Management System forces the companies to measure and monitor their

sources and offers a systematic approach to evaluate results. Continuous improvement rule

of Environmental Management System forces the companies to take actions to save

sources.

Figure 8 Water Consumption

As seen in Figure 8, the last indicator is water consumption per unit product. After

implementation of ISO 14001 Environmental Management System requirements, the water

consumption amount was started to measure and monitor. After monitoring three months, the

measured results had been compared with the expected values (calculated and realised). It has

been seen that there was a big difference between the values. It was understood that there was

a leakage in the water distribution system. After the maintenance of water distribution system,

the water consumption value has decreased from 2.5 m3/Unit Product to 2 m3/Unit Product.

Thus 0.5 m3/Unit Product decreasing in water consumption has been obtained through

systematic approach of Environmental Management System.

2.4 Economical Savings

Factory A gained an economic profit by implementing ISO 14001 Environmental

Management System and waste minimization technologies. In Figure 5.9, you can see the

savings of Factory A by improving of electricity usage and water usage.

Water Consumption

0

0.5

1

1.5

2

2.5

3

2001 2002

Years

Ave

rage

Wat

er

Con

sum

ptio

n Pe

r Uni

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oduc

t (m

3 / U

nit P

rodu

ct)

Improving Electricity and Water Usage

01020304050607080

Beforemodification

Aftermodification

Beforemodification

Aftermodification

Water Usage

$/U

nit P

rodu

ct

Electricity Usage

Figure 9 Improving of Electricity and Water Usage

3. Conclusion

It is obviously that there is a strong link between ISO 14001 Environmental Management

System and waste minimization applications. Generally, environmental management program

consists of heavily waste minimization applications. Waste minimization applications aim to

reduce the waste quantities, raw material consumption / product, energy consumption/product,

etc. So, for this reason, waste minimization is a very important part of productivity increasing

works. Environmental management system is a systematical approach to evaluate the positive

or negative effects of production activities. It is observed that this systematical approach

drives the waste minimization research and applications. For this reason there is an important

effect to reduce production costs and to increase the operational productivity. In this study, it

is Observed That Payback Period of Establishment cost of ISO 14001 Environmental

Management System takes very short time, if it is strictly respect to ISO 14001

Environmental Management System requirements. Also show us; economically it is possible

to have considerable savings by waste minimization applications.

To increase the efficiency of the Environmental Management System, the most important

factor is the organizational structure of Environmental Management System committee. In

this Factory this committee consists of responsible who manage production operations.

Additionally environmental responsibilities added to their job descriptions. By this way, the

responsibility of the Environmental Management System do not belong to only

Environmental Management System Representative, this responsibility was penetrated to all

employees from top management to operators.

Environmental Management System training was organized to suppliers and

subcontractors, which works for factory to give information about Environmental

Management System requirements. It is aimed to penetrate the Environmental Management

System applications to the suppliers and subcontractors. But general economic conditions of

Turkey are not suitable to implement Environmental Management System in small sized

companies. Especially they could not achieve expected waste segregation and disposal

performance due to economical reasons.

It is observed that Environmental Management System applications have been taken as a

systematical tool in waste minimization studies and results has been taken in a very short

time. Environmental Management System has a positive effect for decreasing costs,

increasing productivity and improving work conditions. It is strongly advised to other

companies due to explained reasons and economical benefits, to have competitive advantage

in world market.

In factory A, the total ISO 14001 Environmental Management System implementation

time has taken along eight months. The phases and their time plan can be seen exactly in

Figure 3, Time Schedule of ISO 14001 Implementation. The main operation steps, planning

phase has taken 7 weeks; implementation and operation phase has taken 18 weeks and

checking and corrective action phase has taken 4 weeks.

By implementing ISO 14001 Environmental Management System and by developing

special waste minimization techniques, organizations can gain economical advantages. In

Figure 9, the economical savings of Factory A about water and electricity consumption pays

can be seen. This figure does not mean the organizations implementing these systems only

gain savings by improving water and electricity usage. They can make economical savings on

several subjects (by raw material saving, by waste recycling, etc.). ISO 14001 Environmental

Management is a system, which has several benefits on several issues; economical benefits

should be announced by the organizations, which are implementing this system and

government. By this way the organizations should be supported and convinced to implement

this system.

References

Dods, O.A. (1997). How It All Began- The Story Behind ISO and the Environment. The ISO

14000 Environment. P.4.

ISO, 2001. The ISO Survey of ISO 9000 and ISO 14000 Certificates. Eleventh Cycle: Up

To and Including 31 December 2001. ISO.

BWQI, Bureau Veritas Quality International (2003, August 22). (Personal interview)

Shen, T.T. (1995). Industrial Pollution Prevention. Germany: Springer – Verlag Berlin

Heidelberg.

Stapleton P.J., Glover M.A. (2001). Environmental Management Systems: An

Implementation Guide for Small and Medium-Sized Organizations. United States of

America: NSF International