TABLE 1.
Calculated LC50 Values for Pyrethroid Pesticides in Zebrafish
| Compound | Type | LC50 | CI | Rat LD50 values |
| Deltamethrin (DM) | II | 40 ± 0.08 | 19–100 | 67 |
| Cypermethrin (CM) | II | 65 ± 0.16 | 25–180 | 250 |
| Λ-Cyhalothrin (CH) | II | 110 ± 0.24 | 55–200 | 56 |
| Bifenthrin (BF) | I | 190 ± 0.45 | 90–350 | 55 |
| Permethrin (PM) | I | 300 ± 0.08 | 140–600 | 1200 |
| Resmethrin (RM) | I | n/a | n/a | 2000 |
Note. Values were obtained by plotting percent total mortality data for all trials for each compound against log (dose) and generating a best-fit line. Compounds are presented top to bottom in terms of highest to lowest lethality to zebrafish embryos. Type indicates whether the compound is a type I or II pyrethroid. No LC50 was calculated for resmethrin because the highest dose tested caused no significant (> 20%) mortality. CI represent the doses corresponding to the 16 and 84% mortality levels based on the best-fit line. Highest doses tested (micrograms per liter) were DM, 250; CM and CH, 500; PM, 800; and BF and RM, 3000. Values for rat LD50 data were taken from data cited in Wolansky et al. (2006). n/a, not applicable.