National foreword<br>National Annex NA (informative) - Bibliography<br>Foreword <br>Introduction<br>1 Scope <br>2 Normative references <br>3 Description<br>4 Purity criteria <br>5 Test methods <br>6 Labelling - Transportation - Storage <br>Annex A (informative) - General information on phosphonic <br> acids and salts <br>Annex B (normative) - General rules relating to safety <br>Annex C (informative) - Environmental, health and safety <br> precautions within chemical laboratory<br>Bibliography