EXPOSURE TO ALKANOLAMINES USED IN METAL-WORKING FLUIDS. Maj-Len Henriks-Eckerman Timo Tuomi, Riitta Jolanki Riitta Riala, Katri Suuronen

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1 EXPOSURE TO ALKANOLAMINES USED IN METAL-WORKING FLUIDS Maj-Len Henriks-Eckerman Timo Tuomi, Riitta Jolanki Riitta Riala, Katri Suuronen

2 Introduction Research project at FIOH, : Occupational skin and respiratory diseases of metal workers Project leader: Riitta Jolanki Main researcher: Katri Suuronen The project consisted of the following parts: Statistics of work-related diseases, the years Computer-assisted telephone interviews (CATI) of 800 metal workers for the prevalence of skin and respiratory symptoms Medical evaluation by an occupational physician and clinical investigations Assessment of working conditions in 60 machine shops Occupational hygiene measurements Follow-up study of patients with diagnosed work-related diseases Chemical analysis of MWFs Exposure to alkanolamines / FIOH / M-L Henriks-Eckerman / 2

3 Working conditions in (Finnish) machine shops need to be improved! 35 % of the respondents reported suffering from work related skin, respiratory and eye symptoms Young people are not interested in machinist work due to "dirty" working conditions Results of occupational hygiene measurements can be used to improve working conditions Why measure alkanolamines? alkanolamines are common additives in water-based MWFs their concentrations in MWF concentrates are 5 40 % they are skin and respiratory sensitizers Exposure to alkanolamines / FIOH / M-L Henriks-Eckerman / 3

4 Methods used to measure exposure to alkanolamines Work place air sampling acid-treated glass fibre filter sampling rate L/min ion chromatography (IC) mass spectrometric detection Rinse-off sampling method for hands 200 ml of 20 % isopropanol in polyethylene plastic bags rinsing time 1 min. IC-MS- analysis Chemical analysis of MWFs 9 machine shops, 34 machinists Exposure to alkanolamines / FIOH / M-L Henriks-Eckerman / 4

5 Personal measurement results: air concentrations of alkanolamines Identified Alkanolamine n = 19 Monoethanolamine (EA) Triethanolamine (TEA) Median concentration mg/m Max concentration mg/m Most MWFs in use contained both EA and TEA at the same concentration level (TEA usually as borate) OEL (TWA, 8 h): EA: 2.5 mg/m 3 (1 ppm, Finland) TEA: 5 mg/m 3 (USA, Sweden) The precaution principle: exposure as low as reasonably achievable Exposure to alkanolamines / FIOH / M-L Henriks-Eckerman / 5

6 Personal measurement results: Amounts of alkanolamines in rinse-off samples from hands Identified alkanolamine n = 19 Monoethanolamine (EA) Median Amount* (mg/hand) 1.1 Max amount (mg/hand) 5.8 Triethanolamine (TEA) * These median amounts correspond to an approximate retainment of 1 2 ml of MWF on the operating hand during 2 hours work Exposure to alkanolamines / FIOH / M-L Henriks-Eckerman / 6

7 Potential applications of the results? Estimation of overall exposure to alkanolamines? Use of alkanolamines as markers for assessing airborne exposure to MWFs instead of oil mist? Which preventive measures are most efficient to reduce exposure? Assessing the efficiency of protective gloves during work? Estimation of health risks? Exposure to alkanolamines / FIOH / M-L Henriks-Eckerman / 7

8 Estimation of overall exposure to alkanolamines: Median and maximum amounts (19 samples): Alkanolamine Amount in inhaled air a Amount on the skin b Absorption through the skin c (vapour pressure, Pa) (mg) (mg/working hand) (mg/ working hand ) Median Max Median Max Median Max EA (54) TEA (0.0005) a assumed that inhalation rate was 30 L/min b alkanolamine amounts in the rinse-off samples were corrected for sampling efficiency (about 70 %) and sampling time ( ACD-risk!) c assumed that 20% was absorbed through the skin Exposure to alkanolamines / FIOH / M-L Henriks-Eckerman / 8

9 Machine shop I: Alkanolamine amounts in the MWF and in the air MWF (=100 %) % TEA in MWF % EA in MWF % in MWF concentrate Oil mist in air TEA in air EA in air µg/m3 Exposure to alkanolamines / FIOH / M-L Henriks-Eckerman / 9

10 Machine shop C: Alkanolamine amounts in the MWF and in the air MWF (=100 %) % TEA in MWF % EA in MWF % in MWF concentrate Oil mist in air TEA in air EA in air µg/m3 Exposure to alkanolamines / FIOH / M-L Henriks-Eckerman / 10

11 Conclusions In machinists, skin exposure is considerable compared to inhalation exposure. The gloves in use did not give sufficient protection of the hands against MWFs. Most of them were no real chemical protective gloves. Overall exposure may markedly be reduced by reducing skin exposure Efficiency of protective gloves and working habits may be assessed by using the hand rinsing method. The hand rinsing method is suitable for water soluble additives. Skin exposure measurement is easy to perform with this hand rinsing method. THANK YOU FOR YOUR ATTENTION! Exposure to alkanolamines / FIOH / M-L Henriks-Eckerman / 11