NASA SP-5076

CONTAMINATION CONTROL

HANDBOOK

Prepared by Sandia Laboratories under NASA Order Number H-13245A

for Marshall Space Flight Center

Technology Utilization Diuisiolz OFFICE OF TECHNOLOGY UTILIZATION 1969 NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

lVashington, D. C.

For sale by the Clearinghouse for Federal Scientific and Technical Information

Springfield, Virginia 22151 - Price $3.00

FOREWORD

Rigid control of contamination has contributed to the reliability and precision of vehicles and instruments sent out to explore space. Experience gained in the aerospace community also can be helpful in the pharmaceutical, electronic, and many other indus- tries in which extreme cleanliness is important. This is one of three Special Publi- cations issued by the NASA Office of Technology Utilization to help extend and diffuse current concepts and techniques of rigorous contamination control.

The first of these documents, Contamination Control Principles, SP-5045, was issued in 1967 when a NASA Contamination Control Panel called attention to the wide- spread need for guideline information. The George C . Marshall Space Flight Center, the Manned Spacecraft Center, and the John F . Kennedy Space Center were represented on that panel by, respectively, Frederick J. Beyerle, Quintin T . Ussery., and Dr. John Gayle . Since then a number of special courses for technicians and supervisors employed in clean rooms have been given, and the lectures prepared by James W . Useller for one of those courses at the Lewis Research Center have been published in Clean Room Technology, SP-5074.

This handbook deals in more detail with many of the same matters discussed in SP-5045 and SP-5074. It was prepared for the George C . Marshall Space Flight Center under the direction of H. D . Sivinski, Manager of the Planetary Quarantine Department at the Sandia Laboratories and one of the authors of Contamination Control Principles. He was assisted in this work by a team that included D . M. Garst, K . F . Lindell,

\ W . J. Whitfield, and J . A. Paulhamus and their associates at the Sandia Laboratories; Dr. John Beakley and L . Hughes of the University of New Mexico, and Mrs. Dorothee Drury, technical editor.

The authors’ purpose was to assemble in one volume the information and data most -- likely to be of practical help to persons engaged in contamination control in industrial and related operations. Although commercial names have been used, mention of them does not constitute endorsement by the authors or any Government agency. The group respon- sible for this work drew on many sources of information and has included matters about which there may still be controversy, but the information presented has been verified to the extent believed practical.

Ronald J . Philips, Director Technology Utilization Division Office of Technology Utilization

. . . 111

SECTION

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

CONTAMINATION CONTROL HANDBOOK

INDEX

INTRODUCTION TO CONTAMINATION CONTROL

CONTAMINATION CONTROL IN PRODUCT DESIGN

CONTROL OF SURFACE CONTAMINATION

CONTAMINATION CONTROL IN GASES AND LIQUIDS

CONTROL OF AIRBORNE CONTAMINATION

,- MICROBIAL CONTAMINATION AND ITS CONTROL

RADIATION

CLEAN PACKAGING

MAINTAINING PRODUCT CLEANLINESS

PERSONNEL

GLOSSARY

ACKNOWLEDGMENTS

NOTICE COMMERCIAL NAMES AS USED HEREIN ARE FOR IDENTIFICATION ONLY AND THEIR MENTION DOES NOT CONSTITUTE ENDORSEMENT BY THE AUTHORS OR ANY GOVERNMENT AGENCY.

V

TABLE OF CONTENTS

SECTION 1. - INTRODUCTION TO CONTAMINATION CONTROL

1.1 Contaminants

1.2 Environments

Critical Environment General Environment

1.3 The Origin of Contamination - Sources and Types

1.4 The Mechanisms of Contamination Migration -6

1.5 The Mechanisms of Contamination Retention -6

Gravity Electrostatic Charges Molecular Attraction Viscous Surface Coatings Physical Entrapment

1.6 Bibliography I-7

SECTION 2. - CONTAMINATION CONTROL IN PRODUCT DESIGN

2 .l Control of Contaminants Through Product Design

2.2 Performance Levels

2.3 Bibliography II-8

SECTION 3. - CONTROL OF SURFACE CONTAMINATION III-1

3 .i Cleaning of Surfaces -2

Wetting Surface Tens ion Emulsification Saponification Deflocculation Solvent Activity Organic Solvents pH and its Control Buffer Activity’ Alkalinity and Acidity Hard Versus Soft Water Object of Surface Cleaning Soils and Cleaning Methods

Page I-l

-3

-5

-5 -5

-5

-7 -7 -7 -7 -7

II-1

-1

-8

-2 -2 -3 -3 -3 -4 -4 -5 -6 -6 -7 -7

III-7 vii

Page

Generator Transducers Electronic Components Ultrasonic Cleaning Efficiency Hazards

Drying Methods Displacement Drying

3.4.4

3.5 Cleaning Agents

3.5 .l 3.5.2 3.5.3 3.5.4 3.5.5 3.5.6 3.5.7 3.5.8 3.5.9 3.5.9 .l 3.5.9.2

Kauri-Butanol Values Properties and Characteristics Effects on Materials of Construction Effects on Soils Cleaning Agents and Compatible Cleaning Methods Aqueous Cleaning Solutions Solvent Reclamation and Purity Handling and Storage Hazards and Cautions General Cleaning Agent Safety Rules First Aid and Treatment

3.6 Verification of Surface Cleanliness

3.6 .l Classification of Surface Cleanliness Tests 3.6.2 ASTM Test Methods

3.7 Bibliography

SECTION 4. - CONTAMINATION CONTROL IN GASES AND LIQUIDS

4 .I Contaminants in Gases

4 .l.l Description of Gases 4 -1.2 Purity Levels and Grades 4 .1.3 Gas Systems 4 .1.4 Specifications and Analysis of Gases 4 .1.5 Safe Handling of Compressed Gases

4.2 Contaminants in Liquids

4.2 .l Hydraulic Systems

4.2.2 4.2.3

Design Considerations for a Hydraulic Filtration System

Design Considerations for a Cleanable Hydraulic System

Liquid Filtration Contaminant Measurement Methods

Analysis of Contaminants in Liquids Removal of Contaminants from Liquids

Distillation

4.3 Bibliography IV-31

III-52 -54 -54 -54 -60 -60 -62

-62

-63 -64 -65 -65 -65 -101 -101 -102 -103 -110 -111

-111

-112 III-113

IV-l

-1

-2 -2 -7 -10 -14

-15

-17

-17

-17 -19 -20 -20 -26 -28 -28 -28 -28 -30

ix

Page

SECTION 5. - CONTROL OF AIRBORNE CONTAMINATION V-l

Air Supply -1

Activities Within the Controlled Area -3 The Agglomeration Characteristics of Particulate Matter -4

The Sizes of Airborne Particulates -4

5 .l Atmospheric Air Contamination -4

5.2 Classification and Sources of Airborne Contaminants -6

5.2 .l Contaminant Classification -6 5.2.2 Contaminant Sources -8

Petroleum Industry -8 Metallurgical Industry j -8 Organic Solvent Usage -8 Mineral Processing -9 Motor Vehicles -9 Combustion Processes -9 Other Industry -10 ‘. Natural Environment -10

5.3 Control Techniques for Atmospheric Air Contaminants -10

5;3.1 Air-Pollution Control Devices -13 Aerosols -13 Gases -13

5.3.2 Detecting and Measuring Atmospheric Air Contaminants -14

5.4

Methods Applied to Particulates Methods Applied to Gases

5.3.3 Air-Supply Conditioning

Air Filters for Contamination Control Facilities

-21 -21 -21

-28

5‘.4 .I

5.4.2

Weight Test (Synthetic Dust) -29 Discoloration Test (National Bureau of Standards) -29 DOP Test -29

Types of Air Filters -30 Industrial Filters -30 Ventilation Filters -30 Intermediate Efficiency Filters -30 High-Efficiency Particulate Air (HEPA) Filters -31

Selecting Air Filters -31 High-Efficiency Particulate Air (HEPA) Filters -32

5.5 Nonlaminar Airflow Facilities

5.5,1 Nonlaminar Airflow Rooms 5.5.2 Nonlaminar Airflow Work Stations 5.5.3 Fume Hoods

Conventional Hood Streamlined Entrance Hood @pass Hood Balanced or Compensating Hood

x

-34

-37 -38 -39 -39 -39 -39

v-39

Page

5.6

5.7

5.8

5.9

5 .lO

5 .ll

5.12

Laminar Airflow Facilities v-41

5.6.1 Vertical Laminar Airflow (VLF) Rooms -43 5.6.2 Vertical Laminar Airflow (VLF) Portable Curtain Units -46

5 -6.3 Vertical Laminar Airflow (VLF) Work Stations (Benches -47

5.6.4 Horizontal Laminar Airflow (HLF) Rooms -48

5.6.5 Horizontal Laminar Airflow (HLF) Tunnel -50 5.6.6 Horizontal Laminar Airflow (HLF) Work Stations (Benches) -51

5.6.7 Balanced Laminar Airflow Hood -54

Temperature and Humidity in Clean Room Facilities -56

5.7.1 Temperature 5.7.2 Temperature Monitoring 5.7.3 Humidity 5.7.4 Humidity Monitoring

Clean Room Construction Features

5.8 .l Construction Materials 5.8.2 Walls, Ceilings, and Floors 5.8.3 Plenums and Ducting 5.8.4 Airlocks, Doors, and Pass -Thronghs 5.8.5 Anterooms

Clean Room Furniture and Equipment

-56 -57 -57 -57

-57

-58 -58 3 -59 -59 -60

-60

5.9.1 Chairs or