No. 104 - Miljøstyrelsen

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32 cleaning after an accident. Therefore it is assumed that 10 % of the total amount of mercury evaporates in 30 minutes in the exposure calculations. Thus, in practice a maximum of 0.5 % of the total amount of mercury will presumably evaporate momentarily after which in the following minutes up to 7 % of the total amount of mercury contained in the lamp will evaporate and up to 10 % after 30 minutes. In the worst-case calculations it is therefore assumed that 10 % of the total amount of mercury will evaporate immediately when the lamp breaks. A number of measured values show that maximum concentrations can easily exceed the occupational threshold limit value – even with a very high factor. These maximum values, however, are only present for a brief period of time. Both calculation models and tests show that the concentration of mercury decreases very quickly to low levels far below relevant limit values through continuous ventilation of the room. Tests also show that concentrations of mercury are higher 30 cm above floor height than 1.5 m above floor height. In addition to the height above floor level the concentration of mercury in the room after breakage of a lamp depends on the quantities of mercury in the lamp and, possibly, the form in which mercury is present in the lamp. In one study a certain concern is expressed for postponing cleaning after breakage of a compact fluorescent lamp, since three different tests with the same broken lamp showed that a long waiting time (46 minutes) compared with a short period of time (1 minute) before cleaning up resulted in higher average concentrations (both in 30 cm’s and in 1.5 metre’s height) – despite the fact that a window was opened immediately after the accident in all three cases. Due to the high concentrations measured immediately after the breakage (up to 0.05 mg Hg/m 3 ) it is recommended in the study to put off cleaning for a few minutes – some 5-15 minutes, but no longer than that. Furthermore, tests have shown that in a room cleaned after an accident and where visible residues of the fluorescent lamp and mercury have been removed, concentrations of mercury can exceed the USEPA RfC value (reference concentration without harmful effects) for short periods of time during and after vacuuming: tests show that when floors containing mercury residues are impacted physically, concentrations at floor height may increase substantially. Particularly carpets seem to contain more ”mercury residues” after cleaning compared with a smooth wooden laminate floor. Old wooden floors with large spaces may, however, be just as difficult to clean as a carpet. A vacuum cleaner can easily be contaminated with mercury if it is used to vacuum glass residues from the fluorescent lamp and thereby release mercury vapours to the indoor climate for a long period of time. One of the interviewed manufacturers stated that during an accident it is relevant to remove all visible glass, powder and even droplets of pure mercury. Both glass and powder contain mercury. Several references state that the broken lamp should be removed using materials that are subsequently discarded, i.e. use cardboard pieces to pick up
pieces of broken glas and adhesive tape to collect other physical residues. In this way it is avoided that cleaning utensils such as brooms and vacuum cleaners are contaminated with mercury so that they release mercury vapours in the weeks and months after the accident. Pieces from the broken lamp and various collection tools should be placed in a closed container, e.g. a canning jar, to avoid spreading of mercury vapours. After removal of residues the contaminated area should be cleaned. 33
Page 1 and 2: Survey and health assessment of mer
Page 3 and 4: Contents PREFACE 5 SUMMARY AND CONC
Page 5: Preface This ”Survey and health a
Page 8 and 9: 8 Forms of mercury in compact and s
Page 10 and 11: 10 � Ordinary ventilation: Is slo
Page 13 and 14: 1 Introduction 1.1 Purpose and cont
Page 15: Table 1-1 Maximum permitted content
Page 18 and 19: 18 � Light bulbs without integral
Page 20 and 21: 20 Figure 2-3. Example of lamp with
Page 22 and 23: 22 2.3 Survey of types of mercury c
Page 25 and 26: 3 Release of mercury from broken la
Page 27 and 28: momentarily at the time t=0, i.e. t
Page 29 and 30: same in both 30 cm’s and 1.5 mete
Page 31: Table 3-1 Values for contents of Hg
Page 36 and 37: 36 Physico-chemical data Physical s
Page 38 and 39: 38 Table 4-1 Estimated daily averag
Page 40 and 41: 40 No information is available abou
Page 42 and 43: 42 Table 4-2 Limit values etc. for
Page 44 and 45: 44 A LOAEL of 0.025 mg Hg/m 3 (25
Page 46 and 47: 46 5.1.2 Calculation method For the
Page 48 and 49: 48 In practice, thus, a maximum of
Page 50 and 51: 50 To allow for the impact from ven
Page 52 and 53: 52 effects and even if the value is
Page 54 and 55: 54 � These calculations assume mo
Page 56 and 57: 56 as the source of exposure (the b
Page 58 and 59: 58 Evaporation of mercury will take
Page 60 and 61: 60 Den Store Danske, 2009. In Danis
Page 62 and 63: 62 NEMA, 2000. Environmental Impact
Page 64: 64 WHO, 2010. Joint FAO/WHO Expert

No. 104 - Miljøstyrelsen

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