In 2013, the annual mean nitrogen dioxide levels in London was estimated as 58 ?g / m?but the save and " threshold limit value " is 40 ?g / m?
12.
The threshold limit value ( TLV ) of a chemical substance is a level to which it is believed a worker can be exposed day after day for a working lifetime without adverse effects.
13.
Classification is determined by approved testing measures or calculations and have determined cut-off levels set by governments and scientists ( for example, no-observed-adverse-effect levels, threshold limit values, and tolerable daily intake levels ).
14.
The risk to humans is small if it is probable that there are no long-term effects, the exposure is lower than the threshold limit value ( TLV ), and there are no indications of diseases, symptoms or nuisances.
15.
The American Conference of Governmental Industrial Hygienists has in the past proposed threshold limit values for whole body vibration with certain guidelines also being based on ISO-2631 standards, but no official exposure threshold limits for maintenance of way vehicles have seen widespread publication or enforcement.
16.
Prolong exposure to a very high level of nitrogen dioxide in micro meter-size range, may have an inflammatory effect that principally targets the respiratory tracts leading to chronic nitrogen dioxide poisoning which can occur within a days or weeks after the threshold limit value is excessively exceeded.
17.
It is recommended as a solvent because it is photochemically inactive; however it has a very low safe threshold limit value ( MAK value ) . 2-Hexanone is absorbed through the lungs, orally and dermally and its metabolite, 2, 5-hexanedione, is neurotoxic.
18.
The threshold limit value set by the American Conference on Government Industrial Hygienists is 0.02 lachrymal properties provide an excellent warning of its presence ( at a concentration of 2 4 parts per million ( ppm ) subject's eyes are irritated, while at 21 ppm, subjects could not tolerate the presence of methyl isocyanate in air ).
19.
The American Conference of Governmental Industrial Hygienists has a recommended Threshold Limit Value ( TLV ) for asbestos of 0.1 fibers / mL over an 8-hour shift . OSHA in the United States and occupational health and safety regulatory jurisdictions in Canada use 0.1 fibers / mL over an 8-hour shift as their exposure limits.
20.
At 30 cm distance, the recommended maximum daily exposure was attained between 3 hours and 6 hours, with little difference between the studied 60 Watt incandescent lamp and any bare-spiral CFL . The report states that the threshold limit values used represent otherwise healthy individuals who are not experiencing any hypersensitivity conditions or exposed to substances that increase UV sensitivity.
