| Acute Exposure Guideline Levels |
| AEGL-1 | airbone concentration of a substance at or above which it is predicted that the general population, including "susceptible" but excluding "hypersusceptible" individuals, could experience notable discomfort. Airbone concentrations below AEGL-1 represent exposure levels that could produce mild odor, taste, or other sensory irritation. |
| AEGL-2 | airbone concentration of a substance at or above which it is predicted that the general population, including "susceptible" but excluding "hypersusceptible" individuals, could experience irreversible or other serious, long-lasting effects or impaired ability to escape. Airbone concentrations below AEGL-2 but at or above AEGL-1 represent exposure levels that may cause notable disconfort. |
| AEGL-3 | airbone concentration of a substance at or above which it is predicted that the general population, including "susceptible" but excluding "hypersusceptible" individuals, could experience life-threatening effects or death. Airbone concentrations below AEGL-3 but at or above AEGL-2 represent exposure levels that may cause irreversible or other serious, long-lasting effects or impaired ability to escape. |
| Emergency Exposure Guidance Level |
| EEGL | similar to Emergency Response Planning Guidelines (ERPG). A ceiling guidance level (concentration) for single emergency exposure, by workers, usually lasting 1-24 hours (infrequent during a lifetime). |
| Emergency Response Planning Guidelines |
| ERPG-1 | it is the maximum airbone concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing other than mild transient adverse health effects or perceiving a clearly defined objectionable odor. |
| ERPG-2 | it is the maximum airbone concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects or symptoms that could impair their abilities to take protective actions. |
| ERPG-3 | it is the maximum airbone concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing or developing life-threatening health effects. |
| Immediately Dangerous to Life or Health |
| IDLH | Immediately Dangerous to Life or Health. This refers to a concentration, formally specified by a regulatory value, and defined as the maximum exposure concentration of a given chemical in the workplace from which one could escape within 30 minutes without any escape-impairing symptoms or any irreversible health effects. This value is normally referred to in respirator selection. |
| Seuil des Effets Irréversibles |
| SEI | Seuil des Effets Irréversibles. Il correspond à la concentration, pour une durée d'exposition donnée, au dessus de laquelle la population exposée peut présenter des effets réversibles. |
| Seuil des Effets Létaux |
| SEL | Seuil des Effets Létaux. Il correspond à la concentration, pour une durée d'exposition donnée, au dessus de laquelle on peut observer une mortalité au sein de la population exposée. |
| Seuil des Effets Réversibles |
| SER | Il correspond à la concentration, pour une durée d'exposition donnée, au dessus de laquelle la population exposée peut présenter des effets réversibles. |
| Seuil de Perception |
| SP | Seuil de Perception. Il correspond à la concentration entraînant la détection sensorielle de la substance chimique par la population exposée. |
| Temporary Emergency Exposure Limits |
| TEEL-0 | The threshold concentration below which most people will experience no adverse health effects. |
| TEEL-1 | The maximum airbone concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing more than mild, transient adverse health effects or perceiving a clearly defined objectionable odor. |
| TEEL-2 | The maximum airbone concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects or symptoms that could impair an individual's ability to take protective action. |
| TEEL-3 | The maximum airbone concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing or developing life-threatening health effects. |
| Threshold limit Value - Short Term Exposure Limit |
| TLV-STEL | is the maximum concentration permitted for a continuous 15-minutes exposed period. There may be a maximum of four such periods perday, without least 60 minutes between exposure periods, and provided the daily.TLV-TWA is not exceeded. |
| Threshold Limit Value - Time-Weighted Average |
| TLV-TWA | The time-weighted average concentration fora conventional 8-hour workday and a 40-hour workweek, to which it is believed that nearly all workers may be repeatedly exposed, day after day, without adverse effect. |
| Valeurs Limites d'Exposition Professionnelle |
| VLE | Valeur Limite d'Exposition sur une durée maximum de 15 minutes. |
| VME | Valeur Moyenne d'Exposition sur une durée de 8 heures par jour, 5 jours, par semaine. |