Acute Toxicity of Three Fire-Retardant and Two Foam-Suppressant Foam Formulations to the Early Life Stages of Rainbow Trout (Oncorynchus mykiss)

Conclusions

Ranking of the formulations tested indicated that the fire-suppressant foams were more toxic than the fire retardants. The possible threat posed by fire-fighting chemicals to aquatic ecosystems should not be dismissed because their application concentrations are much greater than the acute toxicity values reported here; thus, both formulation types may have a substantial impact on an aquatic habitat.

Comparison of the tests conducted in both water types indicated that FT GTS-R and Silv-Ex were more toxic in hard water than in soft. Further study of the impact of these formulations in various water types and in field studies may be necessary before the influence of water quality on their toxicity is fully understood.

The eyed-egg life stage was the least sensitive life stage tested, whereas the swim-up fry was generally the most sensitive life stage. Timing and placement of the fire-control chemical applications may be critical to mortality in certain species. Based on our results, application during the eyed-egg life stage may result in lower mortality than application during the fry life stage. Water contamination caused by fire-control chemicals during the salmonid swim-up fry period could be devastating to the local population, especially if the species is endangered as are several western salmonids.

Previous Section -- Discussion
Return to Contents
Next Section -- References