Methylmercury chloride

251.07800

251.96300

204-064-2

19998

2025|3082

DTXSID5020813

White crystals ... or plates from ethanol

2931900090

0

1.27080

Methyl mercury(ii)chloride appears as white microcrystals or crystals. (NTP, 1992)

4.063

167 °C

less than 0.1 mg/mL at 70° F (NTP, 1992)

These compounds should be stored in a refrigerator or a cool dry place away from oxidizers. A regulated, marked area should be established where this chemical is handled, used, or stored ... /Mercury alkyl compounds/

8.5X10-3 mm Hg at 25 deg C

Characteristic

Henry's Law constant = 3.7X10-7 atm-cu m/mol at 25 °C

Aqueous solutions at a concentration of 0.25 mg / mL are stable for 3 weeks in the dark at room temperature. Aqueous 0.0001 M solutions show no degradation after 17.1 hours of midday sunlight. High intensity UV irradiation of solutions causes decomposition (NTP, 1992).

Organometallics

METHYL MERCURY(II)CHLORIDE may be sensitive to light.

II

6.1

UN 2025 6.1/PG 2

3

26/27/28-33-50/53

S13;S28;S36;S45;S60;S61

OW1225000

T+: Very toxic;N: Dangerous for the environment;

Stable. Incompatible with strong oxidizing agents.

P260, P262, P264, P270, P271, P273, P280, P284, P301+P310, P302+P350, P304+P340, P310, P314, P320, P321, P322, P330, P361, P363, P391, P403+P233, P405, P501

H300

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.|Mercury is an element, and therefore its chemical structure cannot be further broken down. In its elemental form, mercury is highly toxic when inhaled. Therefore, incineration of mercury is not recommended as a disposal method. Mercury-containing waste products include waste effluents from chloralkali plants and discarded mercury-containing mechanical and electrical devices ... Under current federal guidelines, mercury and its compounds are considered hazardous substances, and various regulations are in effect to control the emission of mercury into the environment (especially organic compounds) ... Emissions from mercury ore processing facilities and mercury cell chloralkali plants are limited to 2.3 kg/day/facility. Emissions of mercury from the incineration or drying of wastewater sludges is limited to 3.2 kg/day/facility ... In addition, dumping wastes containing more than trace amounts of mercury is prohibited. Recycling of mercury-containing compounds is an important method of disposal. Recycling (retorting) is a treatment for five categories of mercury wastes including: (D009) characteristic mercury; (K106) chloralkali waste; (P065) mercury fulminate; (P092) phenylmercuric acetate; and (U151) elemental mercury ... From 1987 to 1991, annual production of mercury from old scrap averaged nearly 180 metric tons, equivalent to 16% of the average reported consumption during that period (Jasinski 1993). Virtually all mercury can be reclaimed from mercury cell chloralkali plants, electrical apparati, and control instruments when plants are dismantled or scrapped ... Increased recycling would decrease the mercury load from waste sites and treatment plants. As environmental concerns increase with respect to the disposal of mercury, the recovery by recycling and industrial processes will become a more significant source of domestic supply ...|PRECAUTIONS FOR "CARCINOGENS": There is no universal method of disposal that has been proved satisfactory for all carcinogenic compounds & specific methods of chem destruction ... published have not been tested on all kinds of carcinogen-containing waste. ... summary of avail methods & recommendations ... /given/ must be treated as guide only. /Chemical Carcinogens/|PRECAUTIONS FOR "CARCINOGENS": ... Incineration may be only feasible method for disposal of contaminated laboratory waste from biological expt. However, not all incinerators are suitable for this purpose. The most efficient type ... is probably the gas-fired type, in which a first-stage combustion with a less than stoichiometric air:fuel ratio is followed by a second stage with excess air. Some ... are designed to accept ... aqueous & organic-solvent solutions, otherwise it is necessary ... to absorb soln onto suitable combustible material, such as sawdust. Alternatively, chem destruction may be used, esp when small quantities ... are to be destroyed in laboratory. /Chemical Carcinogens/|For more Disposal Methods (Complete) data for Methylmercuric chloride (7 total), please visit the HSDB record page.

DHHS/ATSDR; Toxicological Profile for Mercury (March 1999) TP-46. The ATSDR toxicological profile succinctly characterizes the toxicologic and adverse health effects information for the hazardous substance described here. Each peer-reviewed profile identifies and reviews the key literature that describes a hazardous substance's toxicologic properties. Other pertinent literature is also presented, but is described in less detail than the key studies.[Available from, as of February 12, 2010: http://www.atsdr.cdc.gov/toxprofiles/tp46.pdf]|FAO/WHO Joint Expert Committee on Food Additives; WHO Food Additives Series 44: Methylmercury (2000).[Available from, as of February 11, 2010: http://www.inchem.org/pages/jecfa.html]|FAO/WHO Joint Expert Committee on Food Additives; WHO Food Additives Series 52: Methylmercury (addendum) (2004).[Available from, as of February 11, 2010: http://www.inchem.org/pages/jecfa.html]|USEPA/OST; Water Quality Criterion for the Protection of Human Health: Methylmercury (2001).[Available from, as of February 11, 2010: http://www.epa.gov/waterscience/criteria/humanhealth/]

Flash point data for this chemical are not available; however, it is probably nonflammable. (NTP, 1992)

|Danger|H300 (100%): Fatal if swallowed [Danger Acute toxicity, oral]|P260, P262, P264, P270, P271, P273, P280, P284, P301+P310, P302+P350, P304+P340, P310, P314, P320, P321, P322, P330, P361, P363, P391, P403+P233, P405, and P501|Aggregated GHS information provided by 42 companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Excerpt from ERG Guide 151 [Substances - Toxic (Non-combustible)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

SMALL SPILLS AND LEAKAGE: Should a spill occur while you are handling this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with 60-70% ethanol and transfer the dampened material to a suitable container. Use absorbent paper dampened with 60-70% ethanol to pick up any remaining material. Seal the absorbent paper, and any of your clothes, which may be contaminated, in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with 60-70% ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned. STORAGE PRECAUTIONS: You should protect this material from exposure to light, and store it under ambient temperatures. (NTP, 1992)

MINIMUM PROTECTIVE CLOTHING: If Tyvek-type disposable protective clothing is not worn during handling of this chemical, wear disposable Tyvek-type sleeves taped to your gloves. RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)|PRECAUTIONS FOR "CARCINOGENS": ... Dispensers of liq detergent /should be available./ ... Safety pipettes should be used for all pipetting. ... In animal laboratory, personnel should ... wear protective suits (preferably disposable, one-piece & close-fitting at ankles & wrists), gloves, hair covering & overshoes. ... In chemical laboratory, gloves & gowns should always be worn ... however, gloves should not be assumed to provide full protection. Carefully fitted masks or respirators may be necessary when working with particulates or gases, & disposable plastic aprons might provide addnl protection. ... Gowns ... /should be/ of distinctive color, this is a reminder that they are not to be worn outside the laboratory. /Chemical Carcinogens/

If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty). Use water in flooding quantities as fog. Use foam, dry chemical, or carbon dioxide. /Mercury compounds, solid, n.o.s./|If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors or shows any signs of deforming), withdraw immediately to a secure position. /Mercury alkyl compounds/|Wear appropriate chemical protective gloves, boots, and goggles ... Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. /Mercury compounds, solid, n.o.s./

PRECAUTIONS FOR "CARCINOGENS": A high-efficiency particulate arrestor (HEPA) or charcoal filters can be used to minimize amt of carcinogen in exhausted air ventilated safety cabinets, lab hoods, glove boxes or animal rooms ... Filter housing that is designed so that used filters can be transferred into plastic bag without contaminating maintenance staff is avail commercially. Filters should be placed in plastic bags immediately after removal ... The plastic bag should be sealed immediately ... The sealed bag should be labelled properly ... Waste liquids ... should be placed or collected in proper containers for disposal. The lid should be secured & the bottles properly labelled. Once filled, bottles should be placed in plastic bag, so that outer surface ... is not contaminated ... The plastic bag should also be sealed & labelled. ... Broken glassware ... should be decontaminated by solvent extraction, by chemical destruction, or in specially designed incinerators. /Chemical Carcinogens/|Spill Handling: Evacuate persons not wearing protective equipment from area of spill or leak until clean-up is complete. Remove all ignition sources. Spills should be collected with special mercury vapor suppressants or special vacuums and deposited in sealed containers. Kits specific for clean-up of mercury spills are available. Ventilate area after clean-up is complete. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. /Mercury alkyl compounds/|Environmental considerations - land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. /Mercury compounds, solid, n.o.s./|Environmental considerations - water spill: Use natural barriers or oil spill control booms to limit spill travel. Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. Remove trapped material with suction hoses. /Mercury compounds, solid, n.o.s./

If material not involved in fire: Keep material out of water sources and sewers. /Mercury compounds, solid, n.o.s./|Personnel protection: Avoid breathing dusts and fumes from burning material. Keep upwind. Avoid bodily contact with the material ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water ... If contact with the material anticipated, wear appropriate chemical protective clothing. /Mercury compounds, solid, n.o.s./|SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.|Contact lenses should not be worn when working with this chemical. /Mercury alkyl compounds/|For more Preventive Measures (Complete) data for Methylmercuric chloride (13 total), please visit the HSDB record page.

/GUIDE 151: SUBSTANCES - TOXIC (NON-COMBUSTIBLE)/ Health: Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. /Mercury compounds, solid, n.o.s./|/GUIDE 151: SUBSTANCES - TOXIC (NON-COMBUSTIBLE)/ Fire or Explosion: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways. /Mercury compounds, solid, n.o.s./|/GUIDE 151: SUBSTANCES - TOXIC (NON-COMBUSTIBLE)/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at lease 25 meters (75 feet) for solids. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. /Mercury compounds, solid, n.o.s./|/GUIDE 151: SUBSTANCES - TOXIC (NON-COMBUSTIBLE)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. /Mercury compounds, solid, n.o.s./|For more DOT Emergency Guidelines (Complete) data for Methylmercuric chloride (8 total), please visit the HSDB record page.

PRECAUTIONS FOR "CARCINOGENS": When no regulations exist, the following procedure must be adopted. The carcinogen should be enclosed in a securely sealed, watertight container (primary container), which should be enclosed in a second, unbreakable, leakproof container that will withstand chem attack from the carcinogen (secondary container). The space between primary & secondary container should be filled with absorbent material, which would withstand chem attack from the carcinogen & is sufficient to absorb the entire contents of the primary container in the event of breakage or leakage. Each secondary container should then be enclosed in a strong outer box. The space between the secondary container & the outer box should be filled with an appropriate quantity of shock-absorbent material. Sender should use fastest & most secure form of transport & notify recipient of its departure. If parcel is not received when expected, carrier should be informed so that immediate effort can be made to find it. Traffic schedules should be consulted to avoid ... arrival on weekend or holiday ... /Chemical Carcinogens/|PRECAUTIONS FOR "CARCINOGENS": Procurement ... of unduly large amt ... should be avoided. To avoid spilling, carcinogens should be transported in securely sealed glass bottles or ampoules, which should themselves be placed inside strong screw-cap or snap-top container that will not open when dropped & will resist attack from the carcinogen. Both bottle & the outside container should be appropriately labelled. ... National post offices, railway companies, road haulage companies & airlines have regulations governing transport of hazardous materials. These authorities should be consulted before ... material is shipped. /Chemical Carcinogens/

Permissible Exposure Limit: Table Z-2 8-hr Time Weighted Avg: 0.01 mg/cu m. /Organo alkyl mercury/|Permissible Exposure Limit: Table Z-2 Acceptable Ceiling Concentration: 0.04 mg/cu m. /Organo alkyl mercury/

Recommended Exposure Limit: 10 Hr Time-Weighted Avg: 0.01 mg/cu m. /Mercury (organo) alkyl compounds (as Hg)/|Recommended Exposure Limit: 15 Min Short-Term Exposure Limit: 0.03 mg/cu m, skin. /Mercury (organo) alkyl compounds (as Hg)/

D009; A solid waste containing mercury may or may not become characterized as a hazardous waste when subjected to the Toxicity Characteristic Leaching Procedure listed in 40 CFR 261.24, and if so characterized, must be managed as a hazardous waste. /Mercury/

Adult mallards (Anas platyrhynchos) were fed ... a diet 10 ppm mercury plus 10 ppm selenium. ... When the diet contained 10 ppm selenium in addition to the 10 ppm mercury, none of 12 males became sick. In contrast to the protective effect of selenium against mercury poisoning in males, selenium plus mercury was worse than selenium or mercury alone for some measurements of reproductive success. Both selenium and mercury lowered duckling production through reductions in hatching success and survival of ducklings, but the combination of mercury plus selenium was worse than either mercury or selenium alone. Controls produced an average of 7.6 young per female ... and females fed both mercury and selenium produced 0.2 young. Teratogenic effects also were worse for the combined mercury plus selenium treatment; deformities were recorded in 6.1% of the embryos of controls, 16.4% for those fed methylmercury chloride, 36.2% for those fed selenomethionine, and 73.4% for those fed methylmercury chloride and selenomethionine. The presence of methylmercury in the diet greatly enhanced the storage of selenium in tissues. The livers of males fed 10 ppm selenium contained a mean of 9.6 ppm selenium, whereas the livers of males fed 10 ppm selenium plus 10 ppm mercury contained a mean of 114 ppm selenium. However, selenium did not enhance the storage of mercury. The results show that mercury and selenium may be antagonistic to each other for adults and synergistic to young, even within the same experiment.|Groups of 10 /male ICR/ mice were given methylmercury chloride at a concentration of 40 mg/g of diet, with or without melatonin at a concentration of 20 mg/mL in drinking-water, for 5 weeks. Greater numbers of animals treated with methylmercury alone showed signs of neurotoxicity (abnormal righting reflex, staggering gait, fallen posture) and a higher rate of mortality after 35 days of treatment than the group receiving methylmercury plus melatonin. It was suggested that the anti-oxidative capacity of melatonin reduces the toxicity of methylmercury ...|Groups of six pregnant CD-1 mice were given a single intraperitoneal dose of methylmercury chloride of either 0 or 10 mg/kg bw on day 9 of gestation, and litters were examined for teratological effects on day 17 of gestation. Co-exposure to methylmercury chloride and PK11195 (4 mg/kg), a ligand for the mitochondrial peripheral-type benzodiazepine receptor, reduced the overall incidence of fetal malformation by approximately 2.5-fold... In embryos collected from dams 3 hr after treatment with methylmercury chloride at 5 mg/kg bw on day 9 of gestation, expression of mitochondrial 16S rRNA was decreased approximately three-fold compared with controls, while co-treatment with PK11195 (4 mg/kg) prevented any decrease.

LD50 Rat oral 29.915 mg/kg|LD50 Rat ip 11 mg/kg|LD50 Mouse oral 57.6 mg/kg|LD50 Mouse ip 10 mg/kg|For more Non-Human Toxicity Values (Complete) data for Methylmercuric chloride (7 total), please visit the HSDB record page.

/BIRDS and MAMMALS/ Sixty breeding pairs of captive American kestrels (Falco sparverius) were exposed to a range of sublethal dietary concentrations of mercury (Hg), in the form of methylmercuric chloride, and their subsequent reproduction was measured. Egg production, incubation performance, and the number and percent of eggs hatched decreased markedly between 3.3 and 4.6 mg/kg dry weight of Hg (1.2 and 1.7 mg/kg wet wt), in the diet. The number of fledglings and the percent of nestlings fledged were reduced markedly at 0.7 mg/kg dry weight (0.3 mg/kg wet wt) and declined further between 2 and 3.3 mg/kg dry weight (0.7 and 1.2 mg/kg wet wt). Dietary concentrations of 4.6 mg/kg dry weight (1.7 mg/kg wet wt) were associated with total fledging failure. The estimated decline in fledged young per pair (24%, Bayesian regression) for kestrels consuming 0.7 mg/kg dry weight (0.3 mg/kg wet wt) raises concerns about population maintenance in areas subject to high inputs of anthropogenic Hg. Mercury concentrations in 20 second-laid eggs collected from all groups were related to dietary concentrations of Hg, and the Hg concentrations in 19 of these eggs were related to eggs laid and young fledged. Concentrations of Hg in eggs from the highest diet group (5.9 mg/kg dry wt; 2.2 mg/kg wet wt) were higher than egg concentrations reported for either wild birds or for captive birds (nonraptors) fed dry commercial food containing 5 mg/kg methylmercury. Accumulation ratios of Hg from diets to eggs were higher than those reported for feeding studies with other species.|/BIRDS and MAMMALS/ American kestrels (Falco sparverius) were fed meat diets containing 0, 3, 6, or 12 ppm (dry weight) methylmercury chloride. Birds fed the 12-ppm diet started to show signs of neurotoxicity after 26 days and all died in 39-49 days. One male kestrel fed the 6-ppm diet died after 75 days of exposure and several others showed signs of neurotoxicity after 45 days. None of the birds fed the 3-ppm diet died or showed signs of toxicity. After 59 days of exposure, mercury concentrations in the liver, kidney, and blood of nonreproducing kestrels increased with increasing dietary concentration. Tissue concentrations of mercury also steadily increased over time in birds fed diets with 6 ppm mercury, which were necropsied at 8, 15, 29, or 59 days of exposure, reaching mean total mercury concentrations of 57, 46, and 45 ppm (wet weight) at 59 days in the liver, kidney, and whole blood, respectively. Two pairs of kestrels at each dietary concentration were allowed to breed. Eggs averaged 8.3 and 18.1 ppm (wet weight) total mercury from birds fed 3- and 6-ppm diets, respectively. Feathers grown during mercury exposure contained high concentrations of mercury: Birds fed 3- and 6-ppm diets contained 275 and 542 ppm total mercury, respectively.|/BIRDS and MAMMALS/ Breeding pairs of mallards (Anas platyrhynchos) were fed a control diet or a diet containing 0.5 ug/g mercury (Hg) in the form of methylmercury chloride. There were no effects of Hg on adult weights and no overt signs of Hg poisoning in adults. The Hg-containing diet had no effect on fertility of eggs, but hatching success of eggs was significantly higher for females fed 0.5 ug/g Hg (71.8%) than for controls (57.5%). Survival of ducklings through 6 days of age was the same (97.8%) for controls and mallards fed 0.5 ug/g mercury. However, the mean number of ducklings produced per female was significantly higher for the pairs fed 0.5 ug/g Hg (21.4) than for controls (16.8). Although mercury in the parents' diet had no effect on mean duckling weights at hatching, ducklings from parents fed 0.5 ug/g Hg weighed significantly more (mean = 87.2 g) at 6 days of age than did control ducklings (81.0 g). The mean concentration of Hg in eggs laid by parents fed 0.5 ug/g mercury was 0.81 ug/g on a wet-weight basis.|/BIRDS and MAMMALS/ The ideal study of the effects of methylmercury on the reproductive success of a species of bird would be one in which eggs contained mercury concentrations ranging from controls to very heavily contaminated, all at the same site. Such a study cannot be realized at a mercury contaminated area or under laboratory conditions, but could be achieved by introducing methylmercury into breeding females and allowing them to deposit mercury in their eggs. Female mallards (Anas platyrhynchos) were intraperitoneally injected with solutions of methylmercury chloride dissolved in corn oil, propylene glycol, dimethyl sulfoxide, mineral oil, Olestra, Crisco, lard, hard paraffin, and a combination of hard and soft paraffin. In some cases, egg laying was delayed, either due to the solvent itself (in the case of Olestra, Crisco, and lard) or to the highest concentration of methylmercury chloride (500 ug/g) in some of the solvents. Mercury in eggs ranged from a control level (<0.1 ug/g) to approximately 14 ug/g on a wet weight basis, which more than covers the range of concentrations reported in wild bird eggs. Mercury concentrations in a series of eggs from the same female declined mostly due to excretion of mercury in prior eggs and not because of the length of time since the injection. Intraperitoneal injections hold promise in field studies where one would like to study the reproductive effects of a wide range of methylmercury levels in the eggs of a wild bird and under the natural conditions that exist in the field.|For more Ecotoxicity Excerpts (Complete) data for Methylmercuric chloride (10 total), please visit the HSDB record page.

In the brain of 21-day-old neonatal rats that had been previously exposed to a gavage dose of 6.4 mg Hg/kg as methylmercury chloride in utero, the cerebellum had the highest mercury concentrations and the brainstem had the lowest.|Histochemical localization (by silver amplification) of mercury showed a different distribution. The first deposits of mercury in rat brain became apparent 10 days after exposure to 16 mg/L of methylmercury chloride in drinking-water. The deposits were found initially in the brain stem, then in the cerebral cortex and supraoptic nucleus, and finally in the cerebellum and thalamus. After 20 days, the deposits in the cerebellar cortex were restricted to Purkinje cells and Golgi epithelial cells and those in the spinal cord to the anterior motor neurons; the granule cells of the cerebellar cortex remained unstained ... Similar staining was seen after daily intraperitoneal administration of methylmercury chloride at 0.16-0.8 mg/kg bw ... As the cerebellar granule cells are target cells for methylmercury ..., the absence of staining indicates that only demethylated mercury can be detected with the silver amplification method. When the cortex of the calcarine sulcus of macaque monkeys was stained by the same method, large deposits were seen in the astrocytes and microglia after six months, whereas staining of neurons appeared later and remained faint even after 18 months ... In squirrel monkeys given weekly doses of (3)H-methylmercury, the amount in protein increased, and it was found in damaged but not in undamaged neurons.|Except in rats, the brain:blood ratios were greater than 1 in all species tested ... The ratio was consistently high in monkeys, and in all species it was higher after multiple dosing than after the administration of a single dose. Differences in strain and sex affected the concentration of mercury in blood of mice more than that in brain. The concentration in the brain was higher in female than in male mice. A similar sex difference in brain mercury concentrations, but without a difference in the brain:blood ratio, was seen in rats. Six to 12 days after four daily oral doses of methylmercury chloride at 8 mg/kg bw, the concentration of mercury in brain was 8.8 ug/g in female and 6.7 ug/g in male rats ... In heavily exposed squirrel monkeys, the brain stem had approximately the same concentration as the cerebellum and most of the cerebral regions, with the exception of the occipital lobe, which had the highest concentration ... The thalamus had somewhat higher concentrations than the occipital pole ... In pigs, the concentrations in the cerebrum, cerebellum, and optic nerve differed only slightly, and all had higher concentrations than the spinal cord ... In guinea-pigs, the cerebellum had the lowest concentration ... In rats, the highest concentration was found in the spinal roots and ganglia, closely followed by the cerebral cortex and the cerebellum ..., but the concentrations in the cerebellum, medulla oblongata, and various areas of the cerebrum differed only slightly.|Mercury dynamics in the blood and feathers of captive great skuas, Catharacta skua, were monitored over 56 weeks. Prior to the onset of molt, mercury intake was solely from their maintenance ration of sprats, Sprattus sprattus. For the first half of molt, in addition to mercury intake from sprats, birds were fed different doses of methylmercuric chloride weekly for 20 weeks. During the second half of molt, dosing was stopped and mercury intake was solely from sprats. Blood was sampled throughout the study and feather growth was monitored. Prior to the onset of molt, mercury concentrations increased over the first 51 to 71 days and appeared to level off after this period. Repeated dosing models based on mammalian pharmacokinetics were, in general, too simplistic to be applicable to the birds in the study. During molt, the elimination of mercury from the blood is probably best described by a three-compartment model. Mercury concentrations in feathers were significantly correlated with those in blood at the time of their growth, suggesting that blood and feathers reflect mercury intake over the same time period. Individuals varied in their ability to excrete ingested mercury into the feathers.|For more Absorption, Distribution and Excretion (Complete) data for Methylmercuric chloride (7 total), please visit the HSDB record page.

Increases in the formation of reactive oxygen species in several brain areas have been observed following intraperitoneal administration of methylmercuric chloride to rodents ... A dissociation between increases in lipid peroxidation and cytotoxicity has been demonstrated by showing inhibition of the lipid peroxidation with alpha-tocopherol without blocking the cytotoxicity ... Partial protection /was demonstrated/ against the cytotoxicity with ethylene glycol tetra-acetate (EGTA), suggesting that increases in intracellular calcium may play a role in the cytotoxicity. They ultimately concluded that a synergistic interaction occurred between changes in intracellular calcium homeostasis and intracellular thiol status, culminating in lipoperoxidation, activation of Ca2+-dependent proteolysis, endonuclease activation, and phospholipid hydrolysis ... It has been suggested that neurons are highly sensitive to mercury either because of their low endogenous glutathione content or their inefficient glutathione redox activity. Inhibition of protein synthesis has been reported in neurons from rats exposed to methylmercury ... However, it is unknown whether this inhibition is secondary to neuronal cytotoxicity.|Differences in lipophilicity were ... implicated ... as playing a role in the different effects produced by methylmercuric chloride and mercuric chloride ... /It was/ suggested that the high lipid solubility of methylmercuric chloride may divert that organomercurial to the myelin of the nerve, where it very efficiently inhibits neuronal excitability. Further, they suggested that mercuric chloride probably causes inhibitory activity by binding to sulfhydryl groups in transport proteins that convey the messenger function of intracellular Ca++. This, in turn, leads to both inhibition of muscle contraction and enhancement of HgCl2-induced neuronal inhibition. The authors further suggest that HgCl2 inhibits an internal Ca++ signal necessary for choline reuptake and acetylcholine resynthesis.

SYMPTOMS: Symptoms of exposure to this compound include ataxia, paralysis and incoordination. Other symptoms include nausea, abdominal pain, vomiting, diarrhea, shock, kidney damage, nervous disturbances, tremors of the hands, insomnia, loss of memory, irritability, depression, loosening of teeth and excessive salivation. Paresthesias, neurasthenia, hearing loss, dysarthria and mental deterioration has also occurred. Chorea, athetosis and convulsions have also developed. Death may occur. ACUTE/CHRONIC HAZARDS: This compound may be absorbed through the skin. When heated to decomposition it emits very toxic fumes of chlorine and mercury. (NTP, 1992)|Carcinogens

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas. INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing. INGESTION: Some heavy metals are VERY TOXIC POISONS, especially if their salts are very soluble in water (e.g., lead, chromium, mercury, bismuth, osmium, and arsenic). IMMEDIATELY call a hospital or poison control center and locate activated charcoal, egg whites, or milk in case the medical advisor recommends administering one of them. Also locate Ipecac syrup or a glass of salt water in case the medical advisor recommends inducing vomiting. Usually, this is NOT RECOMMENDED outside of a physician's care. If advice from a physician is not readily available and the victim is conscious and not convulsing, give the victim a glass of activated charcoal slurry in water or, if this is not available, a glass of milk, or beaten egg whites and IMMEDIATELY transport victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, assure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

If this chemical gets into the eyes, irrigate immediately. If this chemical contacts the skin, wash with soap immediately. If a person breathes in large amounts of this chemical, move the exopsed person to fresh air at once and perform artificial respiration. When this chemical has been swallowed, get medical attention. Give large quantities of water. Do not make an unconscious person vomit. /Methyl mercury compounds/|/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Mercury and related compounds/|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with available water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Mercury and related compounds/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Mercury and related compounds/

/SIGNS AND SYMPTOMS/ Methylmercury compounds induce adverse effects on human development - most notably microcephaly and deficits in neurological development ... The dose levels of methylmercury compounds that affect reproduction and development are generally lower than those of inorganic mercury and affect a wider range of end-points. /Methylmercury compounds/|/SIGNS AND SYMPTOMS/ The most consistent and pronounced effects of /chronic/ exposure to ... short-chain alkylmercury compounds such as methylmercury are on CNS. Effects ... are neurological and psychiatric. Common symptoms include depression, irritability, exaggerated response to stimulation (erethism), excessive shyness, insomnia, emotional instability, forgetfulness, confusion, and vasomotor disturbances such as excessive perspiration and uncontrolled blushing. Tremors are also common ... Sensory effects ... occur more consistently and at lower levels of exposure. Earliest sign is paresthesia. At ... higher levels of exposure other effects occur, such as ataxia, constriction of visual field, dysarthria, and hearing defects. These alterations are irreversible when poisoning is severe. Neuropsychiatric effects ... are likely to involve spontaneous fits of laughing and crying and intellectual deterioration.|/SIGNS AND SYMPTOMS/ In humans the neurotoxic symptoms of methyl mercury salts, the Hunter-Russel syndrome, involve focal cerebral and cerebellar atrophy. The granular cell layer of neocerebellum is affected followed by cortical atrophy of area striata, which leads to blindness.|/GENOTOXICITY/ ... Four studies involving subjects exposed to methylmercury compounds from contaminated seal or fish meat were either inconclusive or indicated slight chromosomal effects. /Methylmercury compounds/|For more Human Toxicity Excerpts (Complete) data for Methylmercuric chloride (6 total), please visit the HSDB record page.

methyl mercury chloride

Alkyl mercury compounds have been used as seed disinfectants and for fungicides. They have also been used in organic synthesis. /Mercury alkyl compounds/

Health Hazards -> Carcinogens