Measurements of tetrachloroethylene in dry cleaning plants in Denmark
| Year | No. of plants | No. of observations | Air concentration (mg/m3) | ||||
|---|---|---|---|---|---|---|---|
| Min | Max | Time weighted mean | Geometric mean | GSD | |||
| *The majority in coin operated dry cleaning shops. | |||||||
| †Cannot be calculated from original data. | |||||||
| National Institute of Occupational Health, Denmark | |||||||
| 1947 | 1 | 1 | – | 300 | – | – | – |
| 1949 | 1 | 1 | – | 510 | – | – | – |
| 1956 | 1 | 1 | – | 130 | – | – | – |
| 1962 | 1 | 3 | 70 | 898 | 553 | 351 | 4.5 |
| 1963 | 12* | 27 | 10 | 1150 | 227 | 98 | 5.1 |
| 1964 | 5* | 10 | 30 | 875 | 271 | 148 | 41 |
| 1965 | 4 | 8 | 0 | 7510 | 1218 | 169 | 28 |
| 1967 | 2 | 3 | 100 | 370 | 200 | 169 | 2.1 |
| 1969 | 2 | 3 | 485 | 4380 | 1823 | 1086 | 3.9 |
| 1979 | 1 | 7 | 22 | 190 | 69 | 51 | 2.5 |
| 1980 | 1 | 4 | 32 | 554 | 232 | 136 | 4.1 |
| 1983 | 1 | 1 | – | 211 | – | – | – |
| 1984 | 2 | 4 | 31 | 285 | 174 | 125 | 3.1 |
| 1985 | 1 | 5 | 124 | 618 | 267 | 223 | 1.9 |
| 1986 | 1 | 2 | 35 | 71 | – | – | – |
| 1987 | 1 | 6 | 7 | 31 | 18 | 16 | 1.7 |
| Total | 37 | 86 | |||||
| Danish Technological Institute | |||||||
| 1979–80 | NR | 67 | – | 688 | 60 | –† | – |