ISO 16191:2013

Overview

ISO 16191:2013 - "Water quality - Determination of the toxic effect of sediment on the growth behaviour of Myriophyllum aquaticum" - specifies a laboratory contact test to measure the toxic effects of natural freshwater and artificial sediments on the macrophyte Myriophyllum aquaticum (parrot feather). The method quantifies phytotoxicity within a 10-day exposure by comparing plant growth (fresh mass) in test sediments against a defined control (artificial sediment), allowing calculation of growth inhibition and ECx (effective concentration) values. The procedure addresses both dissolved and particle‑bound contaminants in sediment.

Key topics and technical requirements

• Test organism and format
  • Uses emersed growth of Myriophyllum aquaticum whorls (apical parts), typically three whorls per replicate vessel.
  • Pre-culturing and acclimatization steps required before testing.
• Exposure conditions
  • 10-day contact test comparing test samples to control sediment.
  • Measurement of growth as fresh mass; calculation of growth rate (r) and inhibition (I).
  • Replication and validity criteria specified to ensure reliable results.
• Control and artificial sediment
  • Composition of artificial control sediment (dry mass): peat powder 5%, quartz sand 74%, kaolin clay 20%, CaCO3 1%.
  • Preparation steps for peat suspension, blending, pH stabilization (target ~7.0 ± 0.5).
• Reagents and media
  • Use of Steinberg nutrient medium (Annex B) and specified reagents (e.g., kaolin, quartz sand, peat).
  • Recommended reference substance: 3,5‑dichlorophenol for performance checks.
• Data evaluation
  • Defined calculations for growth rate, mean values across replicates, percent inhibition, and estimation of ECr_x values.
  • Reporting requirements and validity criteria included.
• Safety and interferences
  • Laboratory containment to prevent escape of live plant material.
  • Guidance on potential interferences (e.g., contaminated kaolin or unsuitable peat).

Applications and users

ISO 16191:2013 is practical for:

• Environmental and ecotoxicology laboratories performing sediment toxicity testing.
• Regulatory agencies and consultants assessing dredged material, contaminated sediments, or remediation success.
• Research groups studying macrophyte responses to pollutants and sediment-bound contaminants.
• Wastewater and sediment-monitoring programs requiring standardized biological endpoints (growth inhibition, ECx).

Benefits include a standardized, reproducible measure of sediment phytotoxicity that captures both dissolved and particle‑bound effects using a macrophyte relevant to many aquatic systems.

Related standards

• ISO 5667-15, ISO 5667-16 (sampling and handling of sediments/biotesting)
• ISO 11465 (soil dry matter determination)
• ISO 20079 (duckweed growth inhibition - comparable plant test)
• OECD 218 (sediment-water chironomid test)

Keywords: ISO 16191:2013, Myriophyllum aquaticum, sediment toxicity, water quality, sediment contact test, growth inhibition, artificial sediment, ecotoxicology.