Foreword

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This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 2, Workplace atmospheres.

This second edition cancels and replaces the first edition (ISO 21438-3:2010), which has been technically revised.

The main changes are as follows:

the normative references in Clause 2 has been updated;
terms that are also defined in ISO 18158 have been removed from Clause 3;
the reagents for electronically suppressed ion chromatography have been removed from Clause 6;
Clause 8 has been reduced by referencing relevant standards;
Figure 1 has been added.

A list of all parts in the ISO 21438 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

The health of workers in many industries is at risk through exposure by inhalation of hydrofluoric acid and particulate fluorides. Industrial hygienists and other public health professionals need to determine the effectiveness of measures taken to control workers' exposure, and this is generally achieved by making workplace air measurements. This document provides a method for making valid exposure measurements for hydrofluoric acid and particulate fluorides in use in industry. It is intended for agencies concerned with health and safety at work; industrial hygienists and other public health professionals; analytical laboratories; industrial users of hydrofluoric acid and particulate fluorides, and their workers.

The execution of the provisions and the interpretation of the results obtained with the use of this document is entrusted to appropriately qualified and experienced people.

1 Scope

This document specifies a method for the determination of the time-weighted average mass concentration of soluble particulate fluorides and hydrofluoric acid (HF) in workplace air by collection of the particulate fluorides on a pre-filter and HF on an alkali-impregnated filter and analysis by ion chromatography.

This method is only applicable to determination of particulate fluorides that are soluble using the sample preparation procedure specified.

For aerosol sampling, this method is applicable to the personal sampling of the inhalable fraction of airborne particles, as defined in ISO 7708, and to static (area) sampling.

The method is applicable to the determination of masses of 0,005 mg to at least 1,25 mg of particulate fluorides per sample and 0,015 mg to at least 1,2 mg of HF per sample.

2 Normative references

3 Terms and definitions

4 Principle

5 Requirement

6 Reagents

6.1

6.2

6.3

6.4

7 Apparatus

7.1 Sampling equipment

7.2 Laboratory apparatus

8 Occupational exposure assessment

9 Sampling

9.1 Preliminary considerations

9.2 Preparation for sampling

9.3 Sampling position

9.4 Collection of samples

9.5 Transportation

10 Analysis

10.1 General

10.2 Preparation of test and calibration solutions

10.3 Instrument analysis

10.4 Estimate of limits of detection (LODs) and limits of quantification (LOQs)

10.5 Quality control

10.6 Measurement uncertainty

11 Expression of results

12 Method performance

12.1 Sampling efficiency and sample storage

12.2 Limit of quantification

12.3 Upper limits of the measuring range

12.4 Bias and precision

12.5 Uncertainty of sampling and analysis method

12.6 Interferences

13 Test report

Bibliography