Mercury De-Contamination
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Inorganic Mercury Contamination Reasons
- Broken thermometers and manometers,
- Spillage during scientific experiments,
- Broken blood pressure apparatus and
- During preparation of dental amalgams, etc.
Health Considerations
The following health effects are exhibited by the persons exposed to mercury vapour. long term low levels of exposure cause metal fever like symptoms neuropsychiatric effects such as shyness, blushing, loss of self-confidence, irritability, loss of memory and insomnia short term low level exposures are not a reason for concern. However, the spillage should be cleaned promptly. Mercury vaporises at room temperature. Significant levels of mercury vapour form at room temperature.
Personal Protection
For a small spillage such as from a broken thermometer, use impervious gloves and adequate ventilation.
For a large spillage wear suitable respirators for mercury vapour and impervious gloves. Contaminated clothes should be preferably discarded. If the skin is contaminated wash with soapy water. Always wash hands before smoking and eating. Decontaminate personal protective equipment before storing or reuse.
Spillage cleaning procedure for impervious surfaces For impervious surfaces such as concrete, tile and linoleum floors: ventilate area of spill wear impervious disposable gloves pick up droplets using a pasteur pipette, eye dropper or suction bottle Store the waste in an unbreakable ridded container, preferably under a solution of sodium thiosulphate (photographic fixer).
Note: Do not attempt to clean up by method such as sweeping or mopping. Do not use a household vacuum cleaner as mercury passes through the filter and generates airborne mercury vapour. Specialised vacuum cleaners equipped with charcoal filters are appropriate for such cleaning. sprinkle sulphur powder or a commercial mercury cleaning compound over the spill area. The volume of the decontaminant used should be at least twice the volume of the spill mix well by a brush, where possible allow sufficient time (approximately half an hour) for the formation of mercuric sulphide, which is comparatively harmless vacuum or sweep up, avoid generating dust collect the dust in an impervious sealed container for disposal seal and discard all cleaning equipment.
Cleaning procedure for carpeted areas
Follow steps 1, 2, 3 and 4 as described above. Pick up any broken glass. Chemical decontamination as described for impervious surfaces is not very effective on carpet. Due to high density and low viscosity, mercury droplets seep through the carpet and remain inaccessible to the decontaminant. Therefore, the removal of the carpet is the only way to ensure decontamination. Once the carpet is removed, repeat steps 1, 2, 3 and 4.
Other methods of cleaning
If the mercury droplets have entered the crevices on concrete surfaces, put some decontamination powder in the crevices and seal it with an impervious coating. If the spillage has occurred in an open area such as playground or garden, then the affected soil should be removed. Following this the area may be covered with top soil to bury any residual contamination.
What to do if cleaning cannot be carried out immediately Cordon off the area or room and keep it ventilated. The room must be isolated from any central air-conditioning system.
What chemical can be used for decontamination Sulphur powder (any grade) or specially formulated mercury cleaning compounds can be obtained from chemical suppliers. There are most mercury decontamination kits available from some chemical suppliers.
Storage and transport
Mercury is Schedule Poison (S6). It should be stored and transported in strong sealed impervious containers. It should be kept away from children. Mercury is classed as a Dangerous Goods Class 8, for sea and air transport only (UN 2809 PG lIl).
First Aid
Skin: Immediately wash away with plenty of soap and water. Remove all contaminated clothing. Wash contaminated clothing before reuse. If irritation persists, seek medical advice.
Eyes: Immediately irrigate with copious quantities of water for at least 15 minutes. Eyelids to be held open. In all cases of eye contamination it is a sensible precaution to seek medical advice.
Inhalation: Remove from exposure - avoid becoming a casualty. Seek medical advice. Apply artificial respiration at once if breathing has stopped. In the event of cardiac arrest apply external cardiac massage. If breathing is laboured and patient cyanotic (blue), ensure airways are clear and give oxygen through a face mask.
Ingestion: Thoroughly rinse mouth with water. Give plenty of water to drink to achieve effective dilution. Seek immediate medical assistance.
Biological Monitoring
Blood or urine tests for exposure to mercury are considered to be useful only where there has been a significant exposure to mercury over a period. Blood and urine samples should be taken within a week of the last exposure.
Recommendations
Mercury contamination in hospitals is predominantly caused by the breakage of thermometers and blood pressure apparatus. The lack of maintenance with respect to blood pressure apparatus can result in mercury spillage. Drip trays and other contaminated surfaces should be cleaned by following the cleaning procedure for impervious surfaces. A periodical environmental survey of the relevant work areas and instruments should be carried out to ensure that the correct cleaning protocols are followed Schools should limit mercury stocks to a few drops for demonstration purposes only all mercury users should keep decontamination compound in stock. The stock held should be more than adequate to cope with any anticipated spill areas where mercury is handled should have an impervious floor and benches. The linoleum should be carried at least 10 centimetres up the wall to retain any spill.
Mercury detection in crude oil feedstocks and petroleum refined products to ppb and ppt levels.
Measuring the presence of various mercury species in refinery feedstocks requires accurate measurements of mercury concentration and mercury in its various states, in hydrocarbon feedstocks and the distribution of mercury across the boiling range in its various chemical forms. Some laboratory provide mercury analysis and mercury speciation techniques to rapidly and accurately detect the presence of mercury species in petroleum feedstocks and refined products. Use of these techniques by trained chemists enable the measurement all classes of mercury species.
Different chemical forms of Mercury have their own associated risks for petroleum refineries:
•Elemental Mercuryamalgamates with aluminium alloys, causing materials brittleness in refinery installation
•Organo Mercury species are toxic and require special HSE Measures
•Ionic Mercury species are water soluble and have specific implications on preventing the Mercury to spread throughout the refinery. Mercuric Chloride is one of the most toxic forms as it easily forms organo mercury complexes with proteins
•Mercury species can poison catalysts. Platinum and Rhenium catalysts used in catalytic reforming processes are especially sensitive to Mercury
Mercury in Crude Oil testing methods include:
- GC-ICP-MS (0.1ppb detection limit)
- Elemental Mercury
- Dialkyl Mercury compounds
- Monoalkyl Mercury compounds
- Ionic Mercury compounds
- GC/ICP/MS picks up all Mercury species except particulates
◦Combustion Amalgamation (1 ppb detection limit)
- Total Mercury content
- Picks up all Mercury species including particulates
◦Cold Vapour AA/UV spectrometer (1 ppb detection limit)
- Gas samples
- Mercury sulphide
- Technique of choice for aqueous samples
.
Inorganic Mercury Contamination Reasons
- Broken thermometers and manometers,
- Spillage during scientific experiments,
- Broken blood pressure apparatus and
- During preparation of dental amalgams, etc.
Health Considerations
The following health effects are exhibited by the persons exposed to mercury vapour. long term low levels of exposure cause metal fever like symptoms neuropsychiatric effects such as shyness, blushing, loss of self-confidence, irritability, loss of memory and insomnia short term low level exposures are not a reason for concern. However, the spillage should be cleaned promptly. Mercury vaporises at room temperature. Significant levels of mercury vapour form at room temperature.
Personal Protection
For a small spillage such as from a broken thermometer, use impervious gloves and adequate ventilation.
For a large spillage wear suitable respirators for mercury vapour and impervious gloves. Contaminated clothes should be preferably discarded. If the skin is contaminated wash with soapy water. Always wash hands before smoking and eating. Decontaminate personal protective equipment before storing or reuse.
Spillage cleaning procedure for impervious surfaces For impervious surfaces such as concrete, tile and linoleum floors: ventilate area of spill wear impervious disposable gloves pick up droplets using a pasteur pipette, eye dropper or suction bottle Store the waste in an unbreakable ridded container, preferably under a solution of sodium thiosulphate (photographic fixer).
Note: Do not attempt to clean up by method such as sweeping or mopping. Do not use a household vacuum cleaner as mercury passes through the filter and generates airborne mercury vapour. Specialised vacuum cleaners equipped with charcoal filters are appropriate for such cleaning. sprinkle sulphur powder or a commercial mercury cleaning compound over the spill area. The volume of the decontaminant used should be at least twice the volume of the spill mix well by a brush, where possible allow sufficient time (approximately half an hour) for the formation of mercuric sulphide, which is comparatively harmless vacuum or sweep up, avoid generating dust collect the dust in an impervious sealed container for disposal seal and discard all cleaning equipment.
Cleaning procedure for carpeted areas
Follow steps 1, 2, 3 and 4 as described above. Pick up any broken glass. Chemical decontamination as described for impervious surfaces is not very effective on carpet. Due to high density and low viscosity, mercury droplets seep through the carpet and remain inaccessible to the decontaminant. Therefore, the removal of the carpet is the only way to ensure decontamination. Once the carpet is removed, repeat steps 1, 2, 3 and 4.
Other methods of cleaning
If the mercury droplets have entered the crevices on concrete surfaces, put some decontamination powder in the crevices and seal it with an impervious coating. If the spillage has occurred in an open area such as playground or garden, then the affected soil should be removed. Following this the area may be covered with top soil to bury any residual contamination.
What to do if cleaning cannot be carried out immediately Cordon off the area or room and keep it ventilated. The room must be isolated from any central air-conditioning system.
What chemical can be used for decontamination Sulphur powder (any grade) or specially formulated mercury cleaning compounds can be obtained from chemical suppliers. There are most mercury decontamination kits available from some chemical suppliers.
Storage and transport
Mercury is Schedule Poison (S6). It should be stored and transported in strong sealed impervious containers. It should be kept away from children. Mercury is classed as a Dangerous Goods Class 8, for sea and air transport only (UN 2809 PG lIl).
First Aid
Skin: Immediately wash away with plenty of soap and water. Remove all contaminated clothing. Wash contaminated clothing before reuse. If irritation persists, seek medical advice.
Eyes: Immediately irrigate with copious quantities of water for at least 15 minutes. Eyelids to be held open. In all cases of eye contamination it is a sensible precaution to seek medical advice.
Inhalation: Remove from exposure - avoid becoming a casualty. Seek medical advice. Apply artificial respiration at once if breathing has stopped. In the event of cardiac arrest apply external cardiac massage. If breathing is laboured and patient cyanotic (blue), ensure airways are clear and give oxygen through a face mask.
Ingestion: Thoroughly rinse mouth with water. Give plenty of water to drink to achieve effective dilution. Seek immediate medical assistance.
Biological Monitoring
Blood or urine tests for exposure to mercury are considered to be useful only where there has been a significant exposure to mercury over a period. Blood and urine samples should be taken within a week of the last exposure.
Recommendations
Mercury contamination in hospitals is predominantly caused by the breakage of thermometers and blood pressure apparatus. The lack of maintenance with respect to blood pressure apparatus can result in mercury spillage. Drip trays and other contaminated surfaces should be cleaned by following the cleaning procedure for impervious surfaces. A periodical environmental survey of the relevant work areas and instruments should be carried out to ensure that the correct cleaning protocols are followed Schools should limit mercury stocks to a few drops for demonstration purposes only all mercury users should keep decontamination compound in stock. The stock held should be more than adequate to cope with any anticipated spill areas where mercury is handled should have an impervious floor and benches. The linoleum should be carried at least 10 centimetres up the wall to retain any spill.
Mercury detection in crude oil feedstocks and petroleum refined products to ppb and ppt levels.
Measuring the presence of various mercury species in refinery feedstocks requires accurate measurements of mercury concentration and mercury in its various states, in hydrocarbon feedstocks and the distribution of mercury across the boiling range in its various chemical forms. Some laboratory provide mercury analysis and mercury speciation techniques to rapidly and accurately detect the presence of mercury species in petroleum feedstocks and refined products. Use of these techniques by trained chemists enable the measurement all classes of mercury species.
Different chemical forms of Mercury have their own associated risks for petroleum refineries:
•Elemental Mercuryamalgamates with aluminium alloys, causing materials brittleness in refinery installation
•Organo Mercury species are toxic and require special HSE Measures
•Ionic Mercury species are water soluble and have specific implications on preventing the Mercury to spread throughout the refinery. Mercuric Chloride is one of the most toxic forms as it easily forms organo mercury complexes with proteins
•Mercury species can poison catalysts. Platinum and Rhenium catalysts used in catalytic reforming processes are especially sensitive to Mercury
Mercury in Crude Oil testing methods include:
- GC-ICP-MS (0.1ppb detection limit)
- Elemental Mercury
- Dialkyl Mercury compounds
- Monoalkyl Mercury compounds
- Ionic Mercury compounds
- GC/ICP/MS picks up all Mercury species except particulates
◦Combustion Amalgamation (1 ppb detection limit)
- Total Mercury content
- Picks up all Mercury species including particulates
◦Cold Vapour AA/UV spectrometer (1 ppb detection limit)
- Gas samples
- Mercury sulphide
- Technique of choice for aqueous samples
.
