Table 5

 Estimated picture of the Danish dry cleaning sector around 1970

What we knowWhat we estimate
*This number is close to the number of 2886 VAT registered companies in laundry and dry cleaning in 1970.39
†Estimated from controls (table 1) (143/655) = 21%.
‡Estimated from controls (table 1) (143/831) = 17%.
§(1556(self-employed in cohort) × 48%(% dry cleaners in male controls)) + (1030(self-employed women in cohort) × 18%(% dry cleaners in female controls)). This number is higher than the unpublished number of 695 VAT registered companies in dry cleaning in 1970.5 It should be noted, however, that the industry code in the VAT register is not a quality checked and updated variable.
¶Statistics Denmark (1968 = 3521, 1969 = 4161.5 t, 1970 = 5553.9 t, 1971 = 2567.1 t, 1972 = 3621.7 t).
**Source: Hammershøy.6
††We estimate that tetrachloroethylene constituted 85% of the dry cleaning solvents used in 1970, as it was 75% in 196816 and 90% in 1971.18
‡‡4 855 300 persons lived in Denmark in 1970. From the 1968 dry cleaning industry data we know that the amount of dry cleaned clothes was 4 kg/person/y.
§§93% of the consumption of tetrachloroethylene was used in dry cleaning.22
¶¶Correctly dried clothes contained solvent equivalent to 0.5% of the weight.7
***The air measurements from the National Institute of Occupational Health included geographic outlines of the shops; 100 m3 was the average size of a Danish dry cleaning shop.
All laundry and dry cleaning workers in 1970 census15559 persons
Self-employed laundry and dry cleaning workers in 1970 census2586 persons*
Persons working in dry cleaning shops in 1970 (15559×21%†)3267 persons
Dry cleaners in 1970 (15559×17%‡)2645 persons
Dry cleaning shops in Denmark in 1970932 shops§
Average annual consumption of tetrachloroethylene in Denmark 1968–72¶3885 tons
Self-employed laundry and dry cleaning workers in the biography book**1012 persons
Dry cleaning shops in the biography book with data on number of dry cleaning machines268 persons
Number of machines listed in the biography book in the 268 shops with data on machines539 machines
Average number of machines in dry cleaning shops (539/268)2 machines
Dry cleaning machines in Denmark 1971 (932×2)1865 machines
Tetrachloroethylene operated dry cleaning machines in Denmark 1971 (1865×85%)††1585 machines
Amount dry cleaned textiles in 1968 (4855300 persons×4 kg)‡‡19421 tons
Daily capacity of a dry cleaning shop ((19421 tons/932 dry cleaning shops)/260 working days)80 kg
Tetrachloroethylene used as dry cleaning solvent in Denmark (3885×0.93)§§3613 tons
Consumption of tetrachloroethylene per machine in 1970 (3613/1585)2.3 tons
Consumption of tetrachloroethylene in dry cleaning shops (2.3×2)4.6 tons
Loss of solvent per hour from correctly dried textiles ((0.5%×80 kg)/8 working hours)¶¶50 g
Exposure in the shop ((80 kg×0.5%)/(100 m3×5 air exchange/hour×8 working hours))***100 mg/m3