Overview
ISO 20552:2007 specifies an internationally recognized method to determine the concentration of mercury vapour in workplace air. This standard-published by the International Organization for Standardization (ISO)-outlines procedures using gold-amalgam collection, followed by analysis via cold vapour atomic absorption spectrometry (CVAAS) or cold vapour atomic fluorescence spectrometry (CVAFS). The method aims to help organizations assess workplace exposure to mercury vapour and ensure compliance with occupational safety regulations.
The procedure includes sampling techniques suitable for both short-term (as brief as 15 minutes) and long-term (up to 8 hours) exposure assessments at flow rates generally between 100 mL/min and 1,000 mL/min. It also provides guidance on choosing appropriate sampling equipment and analytical instrumentation to ensure accurate, reliable measurements. However, the method is not suitable in environments where chlorine is present, such as chloralkali plants, and may be subject to interferences from gaseous organo-mercury compounds.
Key Topics
- Mercury Vapour Sampling Methods: Use of gold-coated sorbent tubes for collecting mercury vapour from workplace air, with various adaptations depending on the presence of particulate mercury compounds.
- Analytical Techniques: Measurement of mercury collected on gold sorbent tubes by CVAAS or CVAFS, ensuring high sensitivity and specificity.
- Short-Term and Long-Term Exposure Assessment: Sampling protocols for both brief (15-minute) and extended (8-hour) monitoring, accommodating different risk assessment needs.
- Limitations and Interferences: The standard addresses the method's unsuitability where chlorine is present and potential interference from organo-mercury compounds, which can impact accuracy.
- Workplace Health and Safety: Application in occupational hygiene for compliance with exposure limits and evaluating the effectiveness of engineering controls.
Applications
ISO 20552:2007 delivers practical value for a range of workplace stakeholders:
- Health and Safety Agencies: Provides a validated procedure for workplace air monitoring, ensuring regulatory compliance and safeguarding worker health.
- Industrial Hygienists: Supplies an effective tool for routine assessment of occupational exposure, helping determine the need for exposure controls and personal protective equipment.
- Analytical Laboratories: Serves as a standard operating procedure for the determination of mercury vapour in air samples, supporting accurate and reproducible analyses.
- Industries Utilizing Mercury: Particularly relevant to industries where mercury or its inorganic compounds are handled or processed, aiding in the identification and mitigation of employee exposure risks.
- Occupational Risk Management: Allows for both static (area) and personal sampling to evaluate exposure at fixed locations or in a worker’s breathing zone, supporting comprehensive workplace risk assessments.
Related Standards
To fully implement or complement ISO 20552:2007, consider referencing the following standards:
- ISO 17733: Workplace air-Determination of mercury and inorganic mercury compounds-Method by cold-vapour atomic absorption spectrometry or atomic fluorescence spectrometry. This standard is recommended when mercury concentrations are expected to be above 20 µg/m³ or when chlorine is present.
- EN 689: Guidelines for the assessment of exposure by inhalation to chemical agents for comparison with limit values and measurement strategy.
- ISO 7708: Air quality-Particle size fraction definitions for health-related sampling.
- ASTM E1370-96: Standard Guide for Air Sampling Strategies for Worker and Workplace Protection.
By following ISO 20552:2007, organizations can ensure accurate measurement and effective management of mercury vapour exposure in the workplace, supporting both compliance and worker health protection. For more information and to purchase the official standard, visit the ISO website.