Mercury Handling Guidelines 1. Facts and figures 02 Physical properties of mercury Chemical symbol Hg Density 13.55 g/cm³ (at θ = 25 °C) [1] Molar mass 200.59 g/mol [1] Melting point 234.29 K (-38.86 °C) [1] Boiling point 629.88 K (356.73 °C) [1] Vapor pressure 0.0253 Pa (at θ = 0 °C) [2] 0.17 Pa (at θ = 20 °C) 0.391 Pa (at θ = 30 °C) 0.81 Pa (at θ = 40 °C) 1.69 Pa (at θ = 50 °C) Mass concentration θ in air (after reaching equilibriuim) 2.0 mg/m³ (at θ = 0 °C) [2] 13.6 mg/m³ (at θ = 20 °C) 29.6 mg/m³ (at θ = 30 °C) 62.7 mg/m³ (at θ = 40 °C) 126.0 mg/m³ (at θ = 50 °C) Evaoparation rate 56 µg/(h cm2) • cm² [3] Solubility of elemental mercury in water 0.06 mg/L (at θ = 25 °C) [1] Toxicity • Mercury vapor, which is already formed at room Mercury metal has a liquid state of matter at room tem-tem perature, is highly toxic: vapor with a mercury con-perature (approx. 20 °C) and normal pressure (approx. centration exceeding the TLV (threshold limit value) of 1000 hPa). 0.1 mg/m3 air causes chronic poisoning after pro-longed breathing for 5 to 8 hours per day [12]. Despite Mercury and its compounds are toxic since they react the large number of laboratories involved in polaro-with sulfur-containing enzymes and inactivate them. The graphic/voltammetric work, sensible and proper hand-toxicity depends on the chemical and physical state of ling has ensured that not one single case of mercury the mercury [2, 4–6]. poisoning has been reported to date. The real Hg con centrations measured in the laboratory atmosphere • Metallic liquid mercury is relatively harmless, but it are consistently far below the TLV. is readily resorbed through the skin and finds its way • Organic mercury compounds are very toxic. Dime-through glandular passages into lower skin regions thyl mercury is an extremely toxic form of organic mer-where it is oxidized and carried on as a salt. cury, and very small exposures can cause severe and • The sparingly soluble, inorganic mercury(I) com-irre versible delayed neurotoxicity, including death. pounds and metallic mercury in the form of a coherent Di me thylmercury is thought to be metabolized to me - liquid have low toxicity when taken up orally (but not thyl mercury prior to crossing the blood-brain barrier. through the skin!). Dimethylmercury is quickly absorbed through intact • Mercury(II) compounds are more readily soluble and skin, and it will penetrate latex or polyvinyl gloves. It is therefore much more toxic. highly volatile, will readily evaporate, and can be in - Toxicity to fish: LC50 – Oncorhynchus mykiss (rainbow haled [5]. trout) – 0.016 mg/L – 96 h [13]. Hg(0) < Hg(I) < Hg(II) < Hg vapors < organic Hg Applications with mercury 03 Most of the mercury is used in the chloralkali process. used in polarography is rather small and can be easily While other important applications are using huge kept in a closed material cycle. amounts of mercury, the European demand for mercury Application Mercury consumption Percentage (tons/year) Chlor-alkali production 160 - 190 41.2% Dental amalgams 90 - 110 23.5% Miscellaneous uses 15 - 114 15.2% Chemicals 28 - 59 10.2% Batteries 7 - 25 3.8% Light sources 11 - 15 3.1% Measuring equipment 7 - 17 2.8% Mercury drop electrodes 0.1 - 0.5 0.1% Switches, relays, etc. 0.3 - 0.8 0.1% Source: (COWI – Consultancy within Engineering, Environmental Science and Economics, 2008) [8] Mercury demand in the EU Chlor-alkali production Dental amalgams Hg drop electrodes Miscellaneous uses Measuring equipment Chemicals Light sources Batteries Switches, relays, etc. 2. Handling of mercury in the laboratory 04 Several safety rules, described in detail below, must be observed in the handling of mercury owing to its toxicity. Working in a fume cupboard The handling of mercury should, if possible, always be carried out in a fume cupboard (fume hood). It must be ensured that no mercury drops are spilled on the floor or the lab bench and that no mercury evaporates. Working over plastic trays Vessels containing mercury must be carried in, or at least above, rigid seamless trays made of plastic or enamelled metal. The supplied 6.2711.030 drip pan made of poly-s ty rene is eminently suitable for this. Collecting spilled mercury drops Single mercury drops in this drip pan or any other spilled mer cury can be bound in a simple manner by amalgamation: • With silver (Ag): Mercury drop catcher type 6.2406.000 which is included in the scope of delivery of the 797 VA Computrace. • With tin (Sn): e.g., the thin tin foil supplied by Merck, Darmstadt/Germany [1] • With special laboratory aids: e.g., Mercurisorb-RothTM from Roth, Karlsruhe/Germany [9] e.g., Mercury Spill Clean-up kitTM from J. T. Baker, Phillipsburg, N. J./USA [10] Do not use a vacuum cleaner or a broom! Collecting mercury from the measuring vessel If the MME is used, mercury gathers on the bottom of the measuring vessel at the end of the determination, which must be collected for later disposal. This can be done by collecting the analysis solutions in a large vessel and then decanting. 05 Do not use the mercury catcher in the measuring vessel! Empty reservoir of mercury drop catcher regularly The storage container of the 6.2406.000 mercury drop catcher should be emptied regularly and rinsed thoroughly several times. If the mercury drop catcher is used outside the fume cupboard, keep a minimum safety dis-tance of 50 cm between your head and the mercury trap. Never leave mercury in open vessels Mercury must never be left in open vessels. An upper layer of water or supporting electrolyte in no way sup-presses or reduces mercury evaporation. Store mercury container in fume cupboard The tightly closed, small, unbreakable mercury container as well as all parts that come into contact with mercury must be stored in a fume cupboard, which is always switched on. Ventilate laboratory areas well Rooms where work with mercury is being carried out should be thoroughly aired from time to time. Mercury and jewelry Do not wear jewelry when working with mercury. Pre - cious metals will amalgamate when getting in contact with metallic mercury. This will irreversibly damage your jewelry! 3. Mercury life cycle 06 Goal • No loss of mercury during use • 100% recovery • Occupational health and safety • Environmental protection Purchase Use in the lab Professional Collection in external closed recycling container Purchase of mercury for polarography High-quality and high-purity mercury is needed for polarography. Examples of suppliers for mercury are: Sigma-Aldrich Fluka [7] • 99.9995%, for polarography, Fluka no. 83359 • 99.9999%, electronic grade, Aldrich no. 294594 Merck [1] • 99.6%, for polarography, no. 104403 • ≥ 99.9999%, suprapur, no. 10440 NQR Nordische Quecksilber Rückgewinnung [10] • 99.999999%, minimum order 500 g • Shipment only within European Union (EU) Disposal of used mercury 07 Mercury can be purified, but extensive laboratory setup Options to dispose used mercury from the lab: is required and considerable time needed. For this reason, we recommend to collect waste mercury in a closed con- • Recyclers for fluorescent lamps tainer and then send it for disposal or recycling to the • Recyclers for batteries responsible authorities or authorized companies in ac cor- • Suppliers for mercury dance with the particular national regulations. Important: Mercury must never be disposed with the • Do not reuse mercury. regular municipal waste! • Only fresh, clean, and dry mercury can be used in polaro graphy. • Separate mercury from a black oxide layer prior to use if necessary. 4. General recommendations General handling rules Personal protective equipment • Work under a fume cupboard. • Hand protection • Do not inhale mercury vapors. - Glove material: Nitrile rubber • Avoid contact with the skin. - Glove thickness: 0.11 mm • Avoid generation of vapors or aerosols. - Break through time: > 480 min • Avoid spillage. • Safety glasses • Protective measures General storage rules - Lab coat • Keep mercury in tightly closed vessels. • Hygiene measures • Keep mercury in a well-ventilated place. - Immediately change contaminated clothing. • Keep mercury locked up or in an area accessible only. - Apply skin-protective barrier cream. to qualified and authorized persons. - Wash hands and face after working with mercury. - Do not eat, drink, and smoke when using mercury. 5. Literature dealing with mercury [1] Merck Chemicals http://www.merck-chemicals.com/ [2] Falbe, J. und Regitz, M. 1992 Römpps chemical encyclopedia 9. Stuttgart, New York: Georg Thieme Verlag, 1992. S.3737. ISBN 3-13-734609-6 [3] Euro Chlor – Code of Practice Mercury Housekeeping Environmental Protection 11, 5th Edition September 1998 http://www.chem.unep.ch/mercury/Sector-Specific-Information/Docs/ENV%20Prot%2011%20Edition%205.pdf [4] Mutschler, E. 1970 Arzneimittelwirkungen. Stuttgart: Wissenschaftliche Verlagsgesellschaft 1970. S. 379 [5] John Risher, Ph.D., Rob DeWoskin, Ph.D. 1999 Agency for toxic substances & disease registry. Toxicological Profile for Mercury. 1999. http://www.atsdr.cdc.gov/toxprofiles/tp46.pdf [6] Strong, L. E. 1972 Mercury Poisoning. J. Chem. Educ. 1972, Bd. 28, 49 [7] Sigma Aldrich http://www.sigmaaldrich.com/ [8] COWI – Consultancy within Engineering, Environmental Science and Economics, 2008 European Commission. 12 2008 http://ec.europa.eu/environment/chemicals/mercury/pdf/study_report2008.pdf [9] Carl Roth GmbH + Co KG http://www.carlroth.com [10] Avantor Performance Materials formerly Mallinckrodt Baker Inc. http://www.avantormaterials.com/ [11] Nordische Quecksilber Rückgewinnung http://www.remondis-industrie-service.de/en/ris/spektrum0/produktion/quecksilber/ [12] OSHA Occupational Safety and Health Guideline for Mercury Vapor. http://www.osha.gov/SLTC/healthguidelines/mercuryvapor/recognition.html [13] Mercury(II) chloride G, CH-9101 Herisau Material Safety Data Sheet Mercury(II) chloride. ohm A http://www.sigmaaldrich.com/ , printed by Metr www.metrohm.com SW -05 Subject to change Layout by Ecknauer+Schoch A 8.000.5054EN – 2011