Preface

The basics of preventing electrostatic hazards include the following:

1. grounding and bonding;
2. removing nonconductors; making nonconductors antistatic (dissipative);
3. making workers antistatic and grounding them (making their clothes antistatic and their bodies grounded.);
4. control charge generation ( slow processing);
5. preventing flammable/explosive atmospheres;
6. safety management system;

These specific antistatic measures are not necessarily difficult. Nevertheless, disasters caused by electrostatic hazards still occur. Such disasters seem to occur as a result of a lack of understanding that static electricity is hazardous or from insufficient countermeasures or poor safety management, although the risk of static electricity is well understood and antistatic measures are taken.
Our objective, as reported here, is to prevent electrostatic disasters. It is important that all employees understand the risk posed by static electricity and basic electrostatic safety, and thereby help to build a safe, reliable working environment. In brief, our objective is to raise the level of safety with regard to static electricity in Japan. To this end, the following items are presented:

1. basic understanding of static electricity (the basics for performing risk assessment of static electricity);
2. identification and evaluation of the risk of static electricity;
3. measures against the risk of static electricity;
4. maintenance of measures and management for safety.

A sufficient understanding of the basics is paramount to conducting electrostatic measures, and measures must be based on the basics. Such knowledge will equip employees with a thorough understanding of such measures and prevent workers from engaging in incorrect behaviour that could cause accidents. Moreover, such basic knowledge is indispensable to electrostatic risk assessment. Raising the understanding level of electrostatic safety will eventually help prevent accidents, which is an objective of this document.
When previous versions of these recommendations were published in 1978 and 1988, the hazard control and safety management were based on compliance with guidelines and standards.
However, whatever measures may be taken, static electricity remains a threat as long as there is matter. Therefore, as long as flammable substances are used, "absolute safety (zero-risk)" is an impossibility. In such a situation, risk assessment is essential. The risk assessment requires that hazards be identified and evaluated in advance to determine whether or not the risks were tolerable and, if they were not, which protective measures would be taken to reduce the risks until they were at a tolerable level. This is a risk-reducing control system for safety as a safety technology established in Europe as shown in some EC directives, so-called the Seveso directives I and II, with some serious disasters as a turning point. In .Japan, the revised Industrial Safety and Health Law, put into effect in April 2006, included a provision in Article 28-2 stipulating that efforts be made to perform risk assessment. This document also adopts the risk assessment; therefore, antistatic measures (risk-reducing measures) shown in this document are specified on the precondition that risk assessment be performed. In this point, this document is different from the previous versions. This document specifies risk evaluation for static electricity and universal risk-reducing measures, which may be useful in identifying hazards in various processes. We hope that employees and managers of companies subject to the hazards of electrostatic build-up will find the information provided by this document to be useful for risk reduction and incorporate it into their safety manuals.
The scope and purpose of this document are stated in Chapter 1. The terms and definitions used in this document are presented in Chapter 2. Chapter 3 elaborates the basics of electrostatic safety in order to describe how static electricity develops, resulting in electrostatic discharge and the ignition of flammable matter, and to understand the risks and significance (physics) of the measures. Chapter 4 outlines the risks of static electricity and a brief summary of general antistatic measures. Chapters 5 to 7 contain the fundamentals of antistatic measures, such as grounding and bonding conductors and making workers and nonconductors antistatic.
Chapters 8 to 11 deal with liquids, powders, solids, and gases, respectively, and prescribe antistatic measures for various processes. The appendices present measures to prevent the formation of explosive atmospheres when antistatic measures are unfeasible; Control indicators required for risk assessment; Basic methods of measuring static electricity; and various numerical data required for risk analysis. Moreover, this document contains solutions to a broad variety in hazards associated with static electricity in chemical processes. As a help for risk assessment, the scientific grounds for such measures and methods with references are contained.
Antistatic measures also entail some complications. There may be specific processes to which the recommendations in this document are inapplicable or cases in which antistatic measures are unfeasible. In such cases, expert advice would be needed to avoid providing erroneous solutions.
This document offers supplementary references in the form of separate booklets: TR-84-1: Recommended Standards of Construction of Appliances used for Protection against Electrostatic Hazards, and TR-85-3: A supplement-Applications for Safety Measures to Selected Processes and Facilities.