I initially tested motor oil concentrations of 0.2% and higher. When all the Daphnia magna neonates died, I conducted two experiments using NaCl, since their response to NaCl is known. When the Daphnia magna reacted as expected, I continued the experiments, eventually using motor oil concentrations as low as 0.00017%. Using data from Replicate #1 Experiment #8 24-hour observations, I was able to generate a graph which revealed a motor oil LC50 of 30 mg/l. This is the concentration at which 50% of the organisms die. This very low concentration confirms how only a little bit of oil can cause serious damage to the environment.