Methyl mercury compounds

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safety instructions
Surname

Methyl mercury

CAS number

22967-92-6

GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary
06 - Toxic or very toxic 08 - Dangerous to health 09 - Dangerous for the environment

danger

H and P phrases H: 330-310-300-373-410
P: ?
MAK

Methyl mercury compounds , commonly abbreviated as methylmercury designated (Abbr. MM of English methyl Mercury , MeHg ), are a group of metal-organic compounds of mercury ( mercury-organic compounds ) with a methyl group . They are present as single positively charged ions (CH 3 Hg + ) and can form compounds with negatively charged ions such as the hydroxide or chloride ion . Methylmercury is naturally formed through biomethylation , has a toxic effect and accumulates in the food chain. Methylmercury poisoning manifests itself, for example, in Minamata disease .

Single connections

The methyl mercury compounds mainly include methyl mercury chloride and methyl mercury hydroxide.

Methyl mercury compounds
Surname Methyl mercury chloride Methyl mercury hydroxide
Structural formula Structural formula of methylmercury
other names MM-Cl MM-OH
CAS number 115-09-3 1184-57-2
EC number 204-064-2 214-667-2
ECHA info card 100.003.695 100.013.334
PubChem 409301 14451
Wikidata Q21010649 Q27277443
Molar mass 251.09 g mol −1 232.6 g mol −1
GHS
labeling
06 - Toxic or very toxic 08 - Dangerous to health 09 - Dangerous for the environment
danger
06 - Toxic or very toxic 08 - Dangerous to health 09 - Dangerous for the environment
danger
H and P phrases 300 + 310 + 330-373-410 330-310-300-373-410
no EUH phrases no EUH phrases
260-273-280-301 + 310 + 330-302 + 352 + 310-304 + 340 + 310 ?
Toxicological data

properties

Methylmercury is characterized by a high affinity for sulfur , especially sulfhydryl groups , such as those found in the amino acid cysteine . With these it is able to form covalent bonds. In fish, methylmercury is present as a cysteine ​​complex due to its high affinity for sulfur.

Methylmercury chloride is fat-soluble and skin-permeable and can thus get into the body.

safety instructions

Organic mercury compounds are very toxic and classified as dangerous for the environment. They have water hazard class  3 and are therefore highly hazardous to water. They have a toxic effect on the central and peripheral nervous system and, in higher doses, also damage the liver and kidneys as well as the heart muscles . They continue to disrupt the body's immune response . Special coated protective gloves should be worn during work, as z. B. Nitrile gloves are not sufficient protection.

proof

The analytical determination of the methyl mercury content in environmental and food samples is usually carried out using ICP-MS spectroscopy.

According to a comparative study from 2008 by the Lower Saxony State Office for Consumer Protection and Food Safety, individual fish from exposed species such as shark , swordfish , " Schillerlocken " and tuna can exceed the maximum amount of 1 mg / kg. Based on the Water Framework Directive , taking into account the secondary toxicity for birds and mammals, an environmental quality standard for dissolved methylmercury of 0.004 ng / l was derived. This value is often exceeded.

In southern European countries, the average concentration of methylmercury in breast milk was 0.17–0.68  μg · kg −1 .

United Nations Global Program

The United Nations have in their United Nations Environmental Program Governing Council mercury since 2001 on the list of regulated substances of global pollution . In 2013, the Minamata Convention to Curb Mercury Emissions was signed.

See also

literature

Web links

Individual evidence

  1. ↑ a b Entry on methyl mercury compounds in the GESTIS substance database of the IFA , accessed on December 27, 2019(JavaScript required) .
  2. ↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry organic compounds of mercury with the exception of those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency ( ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
  3. ↑ Swiss Accident Insurance Fund (Suva): Limit values ​​- current MAK and BAT values (search for methylmercury ), accessed on November 25, 2019.
  4. ↑ Entry on methyl mercury chloride in the GESTIS substance database of the IFA , accessed on May 15, 2018(JavaScript required) .
  5. ↑ Template: CL Inventory / not harmonized There is not yet a harmonized classification for this substance . A labeling of methylmercury hydroxide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), which was accessed on May 15, 2018, is reproduced from a self-classification by the distributor .
  6. ↑ Data sheet Methylmercury (II) chloride, PESTANAL at Sigma-Aldrich , accessed on May 13, 2017 ( PDF ).
  7. ↑ a b c Entry on Methylmercuric chloride in the Hazardous Substances Data Bank , accessed February 23, 2011.
  8. ^ Federal Environmental Specimen Bank : Determination of methyl mercury compounds in environmental samples by ICP-MS , March 2011, accessed on September 2, 2016.
  9. ↑ Federal Institute for Risk Assessment (BfR): Exposure to methyl mercury due to fish consumption and the establishment of analytical methods for determining methyl mercury in fishery products , 2008, accessed on September 2, 2016.
  10. ↑ Derivation of a water-based quality standard for secondary poisoning of mercury
  11. ↑ Scientific Opinion on the risk for public health related to the presence of mercury and methylmercury in food. In: EFSA Journal. 10, 2012, p. 2985, doi : 10.2903 / j.efsa.2012.2985 .
  12. ^ DS Kim, K Choi: Global trends in mercury management. In: J Prev Med Public Health , 2012, 45 (6), pp. 364-373, PMID 23230466 .