Toxicology
In the realm of toxicology, several measures are commonly used to describe toxic dosages according to the degree of effect on an organism or a population, and some are specifically defined by various laws or organizational usage. These include:
- LD50 = Median lethal dose, a dose that will kill 50% of an exposed population
- NOEL = No Observed Effect Level, the highest dose known to show no effect
- NOAEL = No Observed Adverse Effect Level, the highest dose known to show no adverse effects
- PEL = Personal Exposure Limit, the highest concentration permitted under US OSHA regulations
- STEL = Short-Term Exposure Limit, the highest concentration permitted for short periods of time, in general 15–30 minutes
- TWA = Time-Weighted Average, the average amount of an agent's concentration over a specified period of time, usually 8 hours.
Read more about this topic: Dose (biochemistry)