Round robin test for odour testing of migration waters.

Area of Science:

• Sensory science
• Materials science
• Environmental science

Background:

• Standard EN 1420-1 assesses odor from organic materials in contact with drinking water.
• Round robin tests are crucial for validating analytical methods and ensuring inter-laboratory comparability.
• Assessing odor is vital for public health and consumer acceptance of water supply materials.

Purpose of the Study:

• To evaluate the performance of the EN 1420-1 standard through a collaborative inter-laboratory study.
• To assess the suitability of reference substances for qualifying sensory panels and individual assessors.
• To compare different testing options and identify improvements for odor analysis reproducibility.

Main Methods:

• 14 laboratories across 10 European countries participated in the round robin test.
• Plastic pipe segments underwent migration tests and odor analysis of migration water according to EN 1420-1.
• Reference substances (Methyl tert-butyl ether, 1-butanol, hexanal) were tested for panel qualification, and both unforced and forced choice methods were applied.

Main Results:

• Methyl tert-butyl ether (MtBE) and 1-butanol proved effective for panel qualification, unlike hexanal.
• Unforced choice testing showed advantages in panellist qualification and data analysis compared to forced choice.
• Odor threshold number (TON) results for the pipe material showed a range of ±1.5 dilutions, indicating potential for improvement.

Conclusions:

• Reference substances are valuable for training, auditing, and selecting sensory panellists to enhance odor test reliability.
• Incorporating individual panellist sensitivities more strongly can improve the reproducibility of odor assessments.
• The findings from this round robin test will inform the revision process of the EN 1420-1 standard.