Latency Period The period of time between an exposure and onset of toxicity. LC0 Lethal Concentration 0%  The calculated concentration of a gas at which none of the population is expected to die. LC10 Lethal Concentration 10%.  The calculated concentration of a gas at which 10% of the population is expected to die. LC50 Lethal Concentration 50%.  The calculated concentration of a gas at which 50% of the population is expected to die. LC90 Lethal Concentration 90%.  The calculated concentration of a gas at which 90% of the population is expected to die. LD0 Lethal Dose 0%.  The estimated dose at which none of the population is expected to die. LD10 Lethal Dose 10%.  The estimated dose at which 10% of the population is expected to die. LD50 Lethal Dose 50%.  The estimated dose at which 50% of the population is expected to die. LD90 Lethal Dose 90%.  The estimated dose at which 90% of the population is expected to die. Linearized Multistage Model A conservative quantitative cancer assessment model used by the EPA.  It assumes linear extrapolation with a zero dose threshold from the upper confidence level of the lowest dose that produced cancer in an animal test or in a human epidemiology study. Lipid Soluble Capable of being dissolved in fat or in solvents that dissolve fat.  Usually non-ionized compounds. LOAEL Lowest Observed Adverse Effect Level.  The lowest dose in a study in which there was an observed toxic or adverse effect.