Long term exposure limit

Long-term exposure limit (LTEL) An exposure limit requirement based on the assumption that the total body intake of a pollutant below this limit over an 8-hour working day will have no harmful effect on the worker over a working life. See also Maximum exposure limit (MEL), Occupational exposure limit (OEL), and Short-term exposure limit (STEL). 

Specific short-term exposure limits are listed by the HSE for those chemicals which pose a risk of acute effects from brief exposures. For other chemicals a recommended guideline for controlling short-term excursions is to restrict them to 3x long-term exposure limit averaged over a 10min period. 

Solvents that are currently assigned a workplace exposure limit (eight-hour long-term exposure limit) that is less than or equal to 100 ppm are marked in Table 11.7 with an arrowhead ( ) (data from EH40/2005). 

Handling precautions the long-term exposure limit (8-hour TWA) for chlorodifluoromethane is 3590 mg/m (1000 ppm). 

In the UK, the short-term (15-minute) occupational exposure limit for monoethanolamine is 15 mg/m (6 ppm) and the long-term exposure limit (8-hour TWA) is 7.6mg/m (3ppm).< >... 

In UK and Finland, the following values are used long-term exposure limit 8h TWA of 100 ppm (560mgm ) and short-term exposure limit of 15min at 150ppm (840mgm ). 

U.S. Department of Health and Human Services long-term exposure limits recommended for protection of workers (8 hr average)and the general public (72 hr average). 

Titanium dioxide pigment, because of its small particulate size ( 20 pm), is classified as a nuisance, and long-term exposure limits of 10 mgm total dust and 5 mgm respirable dust have been specified by the UK Health and Safety Executive and the American Conference of Governmental Hygiemsts (ACGIH 2002). In Germany, a maximum allowable concentration of 6 mgm in workplaces (MAK) has been specified (Anonymous 2002). 

The long-term exposure limit to solvent vapours sets a limit for the average exposure over an 8-h working day. It applies to workers in a plant and not to people living in the neighbourhood. 

As an air-borne dust, its long term exposure limit (8-hour time-weighted average) is 10 mg/m of total inhalable dust and 5 mg/m of respirable dust (respirable being defined in [34.1]). More stringent standards apply if the crystalline silica content exceeds 1 %. 

As airborne dusts, the long term exposure limits (8-hour time-weighted average) for quicklime and hydrated lime are 2 and 5mg/m of dust respectively [34.1]. The dusts are irritating to the respiratory tract and may cause inflammation. 

Mg has no harmful effect on the environment and is an essential nutrient for animals and plants in small concentrations. UK occupational c5q)osure limits give a long-term exposure limit (8-hour TWA) of 4 mg/m for MgO dust and respirable fume (expressed as Mg). 

The workplace exposure limits are subject to time-weighted averaging. There are two such time-weighted averages (TWA) - the long-term exposure limit (LTEL) or 8 hour reference period and the short-term exposure limit (STEL) or 15 minute reference period. The 8 hour TWA is the maximum exposure allowed over an 8 hour period so that if the exposure period was less than 8 hours the workplace exposure limit is increased accordingly with the proviso that exposure above the LTEL value continues for no longer than 1 hour. 

Long-Term Exposure Limits (LTEL) The maximum concentration to... 

---