ASTM D7391

ASTM D7391 is the standard test method for categorization and quantification of airborne fungal structures in an inertial impaction sample by optical microscopy. It provides a consistent way to examine collected airborne material and identify fungal structures with greater clarity and comparability. This matters for laboratories, consultants, and quality-focused users that need reliable microscopic results from impaction samples. ASTM D7391 helps support more uniform interpretation, documentation, and reporting of airborne fungal observations.

Purpose of ASTM D7391

The purpose of ASTM D7391 is to define a test method for classifying and measuring airborne fungal structures recovered from an inertial impaction sample using optical microscopy. In practical terms, it gives users a structured approach for viewing collected particles, distinguishing relevant fungal forms, and quantifying findings in a repeatable way. The standard is useful when a clear technical basis is needed for sample evaluation, comparison, and reporting. It helps align laboratory practice with a recognized ASTM standard.

Common use cases of ASTM D7391

ASTM D7391 is commonly used in workflows that involve airborne sampling followed by microscopic examination of inertial impaction samples. It is relevant when a laboratory needs to categorize and quantify fungal structures collected from air. The standard may support environmental assessment, indoor air investigations, and other monitoring tasks where optical microscopy is used to examine sample deposits. It is also helpful for organizations that need consistent results across multiple samples, analysts, or testing events.

Why ASTM D7391 matters

ASTM D7391 matters because it supports more consistent interpretation of airborne fungal data from microscopy-based analysis. A defined test method can improve comparability between reports, reduce ambiguity in sample review, and strengthen quality control in testing programs. For purchasers and technical users, it provides a clearer basis for specifying analytical expectations and evaluating laboratory performance. ASTM D7391 can also help reduce risk by promoting a more standardized approach to categorization and quantification.

• Optical microscopy of inertial impaction samples
• Categorization of airborne fungal structures
• Quantification-focused sample review
• Repeatable laboratory reporting
• Quality control for airborne biological analysis