16:38 Oct 29, 2009 

Many thanks to both of you for your help. In the meantime I have found many EU product safety data sheets, and they all give the UK translation "WEP-TWA" (Workplace Exposure Limit-Time-Wieghted average)for the Spanish "VLA-ED" (valores limites ambientales- exposición diaria) for instance. Likewise, "VLA-EC" (valores limites ambientales-exposición de corta duración" is translated on all those safety data sheets as "WEL-STEL" (Workplace Exposure Limit-Short-term exposure) in UK English, etc. so that is what I am going to use. Many thanks again for your much appreciated help! H.

16:14 Oct 29, 2009 

Please clarify.

16:13 Oct 29, 2009 

Actually, in the meantime I have come across a definition in the same document. It says: "Los VLA son valores de referencia para las concentraciones de los agentes químicos en el aire y representan condiciones a las cuales se cree (...) que la mayoría de los trabajadores pueden estar expuestos 8 horas diarias y 40 semanales, durante toda su vida laboral, sin sufrir efectos adversos para su salud," which in English would be "Threshold Limit Value - Time Weighted Average (TLV-TWA)": average exposure on the basis of a 8h/day, 40h/week work schedule" (from http://en.wikipedia.org/wiki/Threshold_Limit_Value).