Sampling Combustion Effluents and Other Stationary Sources for the Subsequent Determination of Hydrogen Cyanide

D7295-18: Standard Practice for Sampling Combustion Effluents and Other Stationary Sources for the Subsequent Determination of Hydrogen Cyanide

Accurate measurement of hydrogen cyanide (HCN) emissions from industrial processes and combustion events is essential for environmental compliance, worker safety, and public health. ASTM D7295-18 provides an authoritative and comprehensive methodology for collecting these critical samples. This industry-leading standard ensures that professionals can reliably obtain representative samples for subsequent laboratory analysis, enabling informed decision-making and effective risk management.

What is D7295-18?

ASTM D7295-18, "Standard Practice for Sampling Combustion Effluents and Other Stationary Sources for the Subsequent Determination of Hydrogen Cyanide," outlines a proven method for collecting gaseous samples containing hydrogen cyanide from various emission sources. Developed by ASTM International, this standard is designed to ensure the integrity of HCN samples from the point of collection to laboratory analysis, facilitating accurate quantification of this highly toxic compound.

Scope & Purpose

This standard governs the procedures for sampling hydrogen cyanide (HCN) from a wide range of sources, including combustion devices, industrial stacks, and enclosed atmospheres such as smoke chambers or work areas. It covers the collection of both gaseous HCN and entrained cyanide-containing particles. While not directly detailing analytical methods, it specifies sample collection techniques that are compatible with subsequent quantitative analysis of cyanide ions. The practice is intended for use in situations where the presence and concentration of HCN are of concern, such as in emissions monitoring, fire science research, and occupational safety assessments. It does not cover sampling for other cyanide species or the analytical determination itself.

Who Must Comply?

• • Primary audience: Environmental Engineers, Chemical Engineers, Safety Officers, Air Quality Specialists, and Laboratory Technicians involved in emissions testing and industrial hygiene.
• • Industries affected: Manufacturing, Energy Production (including power plants and internal combustion engines), Chemical Industry, Research and Development (especially in fire science and material flammability), Fire Science Laboratories, and Environmental Consulting firms.
• • Compliance nature: Voluntary, but often recommended or required by regulatory bodies and internal company policies for accurate emissions reporting and safety protocols.
• • Enforcement: Typically by environmental regulatory agencies (e.g., EPA), occupational safety and health administrations (e.g., OSHA), and internal company audit processes.

Key Requirements Overview

The standard requires professionals to utilize calibrated sampling equipment capable of maintaining consistent flow rates. Key provisions include:

• • Impinger Design and Operation: Mandates the use of specific impinger configurations, typically containing a sodium hydroxide solution, to efficiently absorb and trap HCN from the sampled gas stream.
• • Material Compatibility: Specifies the use of inert materials (e.g., PTFE) for sampling probes and tubing to prevent sample contamination or loss.
• • Temperature Control: Recommends heated sampling lines when encountering moist air to prevent condensation that could affect sample integrity.
• • Particulate Capture: Includes provisions for capturing fine particulates that may pass through the impinger, ensuring these are accounted for in the total cyanide determination.
• • Quality Assurance: Encourages the use of duplicate and spiked samples to assess sampling precision and analytical recovery.

Related Standards & References

ASTM D7295-18 works in conjunction with