Are natural deep eutectic solvents always a sustainable option? A bioassay-based study.

Area of Science:

• Environmental Chemistry
• Ecotoxicology
• Green Chemistry

Background:

• Traditional organic solvents present environmental and health concerns due to volatility, toxicity, and lipophilicity.
• Green Chemistry promotes sustainable alternatives like Ionic Liquids (ILs), bio-based solvents, and Natural Deep Eutectic Solvents (NADESs).

Purpose of the Study:

• To conduct an ecotoxicological screening of 15 NADESs.
• To assess the impact of NADESs on various marine and freshwater organisms and endpoints.

Main Methods:

• Utilized a battery of marine and freshwater bioassays.
• Tested endpoints included immobilization (Daphnia magna), growth inhibition (Raphidocelis subcapitata, Phaeodactylum tricornutum), larval development (Ficopomatus enigmaticus), and bioluminescence inhibition (Aliivibrio fischeri).

Main Results:

• Generally, all tested NADESs exhibited negligible toxicity towards aquatic invertebrates.
• A significant biostimulation effect was observed in algal assays, with 8 out of 15 NADESs increasing growth by over 100% in Raphidocelis subcapitata.
• Aliivibrio fischeri bioluminescence and Ficopomatus enigmaticus larval development were not significantly affected.

Conclusions:

• NADESs demonstrate low toxicity to invertebrates, supporting their classification as sustainable solvents.
• The potential for biostimulation in algae raises concerns about the ecological impact of NADESs release into aquatic environments.
• Further research is needed to understand the long-term ecosystem functioning implications of NADESs.