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Acute Toxicity of Fire Control Chemicals to Daphnia magna (Straus) and Selenastrum capricornutum (Printz)

Susan F. McDonald,* Steven J. Hamilton,* Kevin J. Buhl,* and James F. Heisinger †

*Columbia Environmental Research Center, U.S. National Biological Service, Field Research Station, Yankton, South Dakota 57078; and †Biology Department, University of South Dakota, Vermillion, South Dakota 57069

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Abstract

Acute toxicity tests were conducted exposing Daphnia magna Straus (daphnid) in soft and hard reconstituted waters (hardness 42 and 162 mg/liter as CaCO₃, respectively), and Selenastrum capricornutum Printz (algae) in ASTM algal assay medium (hardness 15 mg/liter as CaCO₃) to fire retardants Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F, and foam suppressants Phos-Chek WD-881 and Silv-Ex. The chemicals were slightly toxic to practically harmless to daphnids and moderately toxic to algae. Water quality did not consistently alter the toxicity of the test chemicals to daphnids. The most toxic chemical to daphnids was Silv-Ex (48-hr EC₅₀ 7 mg/liter in soft and hard waters), whereas the least toxic chemical to daphnids was Fire-Trol LCG-R (48-hr EC₅₀ 848 mg/liter in soft water, 813 mg/liter in hard water). The most toxic chemical to algae was Fire-Trol LCG-R (96-hr IC₅₀ 10 mg/liter), and the least toxic chemical was Phos-Chek D75-F (96-hr IC₅₀ 79 mg/liter). Un-ionized ammonia concentrations near the EC₅₀ or IC₅₀ value in tests with the Fire-Trol compunds were frequently equal to or above LC₅₀ un-ionized ammonia concentrations. Un-ionized ammonia concentrations in tests with Phos-Chek D75-F were low, thus other toxic components present in the compounds probably contributed to the toxicity. When compared to the daphnids tested in ASTM soft water, the Fire-Trol compounds were most toxic to algae, whereas Phos-Chek D75-F and the foam suppressants were most toxic to daphnids. The results of these tests are comparable to those obtained from research conducted in other laboratories with the same species and similar chemicals. Accidental entry of fire-fighting chemicals into aquatic environments could adversely affect algae and aquatic invertebrates, thus disrupting ecosystem function.

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This resource is based on the following source:

McDonald, Susan F., Steven J. Hamilton, Kevin J. Buhl,  and James F. Heisinger.
     1995.  Acute toxicity of fire control chemicals to Daphnia magna
     (Straus) and Selenastrum capricornutum (Printz).  Ecotoxicology and 
     Environmental Safety.  33(0007):62-72.
     

This resource should be cited as:

McDonald, Susan F., Steven J. Hamilton, Kevin J. Buhl,  and James F. Heisinger.
     1995.  Acute toxicity of fire control chemicals to Daphnia magna
     (Straus) and Selenastrum capricornutum (Printz).  Ecotoxicology and 
     Environmental Safety.  33(0007):62-72. 
     Northern Prairie Wildlife Research Center Online. 
     http://www.npwrc.usgs.gov/resource/othrdata/fireweb/damaseca.htm
     (Version 02MAR98).

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Table of Contents

• Introduction
• Materials and Methods
  • Culture
  • Dilution Water
  • Test Chemicals
  • Acute Toxicity Testing
  • Ammonia Analysis
  • Nitrate and Nitrite Analysis
  • Statistical Analysis
• Results
  • Water Quality
  • Acute Toxicity
  • Ammonia
  • Nitrate and Nitrite
• Discussion
  • Acute Toxicity
  • Ammonia
  • Nitrate and Nitrite
  • Trophic Interaction
  • Interlaboratory Comparison
  • Relation to Environmental Considerations
• Conclusions
• References

Tables

• Table 1 -- Test Chemical Composition of the Five Fire-Fightng Chemicals
• Table 2 -- Acute Toxicity of Five Fire-Fighting Chemicals to Neonate D. magna
• Table 3 -- Acute toxicity of Five Fire-Fighting Chemicals to Selenastrum
• Table 4 -- Summary of the Ammonia Characteristics of Five Fire-Fighting Chemicals Used in Tests with Neonate D. magna
• Table 5 -- Summary of the Ammonia Characteristics of Five Fire-Fighting Chemicals Used in Tests with S. capricornutum
• Table 6 -- Summary of the Nitrate-Nitrogen and Nitrite-Nitrogen Characteristics of Three Non-Foam Fire-Fighting Chemicals
• Table 7 -- Summary of Reported Acute Toxicities of Fire Retardant and Foam Suppressant Chemicals
• Table 8 -- Formulation of Field Mixtures and the Ratio of the Mixture Concentration to the Acute Toxicity Value

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Acknowledgments

This study, part of a master's thesis by the first author, was sponsored by the Interior Fire Coordinating Committee, U.S. Department of the Interior. The authors thank A. Bullard, M. Ehlers, and M. Gaikowski for excellent technical assistance in conducting toxicity tests, and K. Faerber for typing the manuscript.

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