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Chemical Datasheet

METHYL MERCURY(II)CHLORIDE

6.1 - Poison

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 115-09-3
  • 2025
  • Poison
none
NIOSH Pocket Guide International Chem Safety Card
Mercury (organo) alkyl compounds (as Hg) none
NFPA 704
data unavailable
General Description
PHYSICAL DESCRIPTION: White microcrystals or crystals. (NTP, 1992)

Hazards

Reactivity Alerts
none
Air & Water Reactions
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).
Fire Hazard
Flash point data for this chemical are not available; however, it is probably nonflammable. (NTP, 1992)
Health Hazard
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)
Reactivity Profile
METHYL MERCURY(II)CHLORIDE may be sensitive to light.
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

Isolation and Evacuation
Excerpt from 151 Polymerizable warning [Substances - Toxic (Non-Combustible)]:

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 the immediate precautionary measure distance, in the downwind direction, as necessary.

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, 2020)
Firefighting
Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. (NTP, 1992)
Non-Fire Response
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)
Protective Clothing
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)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
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)

Physical Properties

Chemical Formula:
  • CH3HgCl
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: data unavailable
Melting Point: 338°F (NTP, 1992)
Vapor Pressure: 0.0085 mmHg (NTP, 1992)
Vapor Density (Relative to Air): data unavailable
Specific Gravity: 4.06 at 77°F (NTP, 1992) - Denser than water; will sink
Boiling Point: data unavailable
Molecular Weight: 251.08 (NTP, 1992)
Water Solubility: less than 0.1 mg/mL at 70°F (NTP, 1992)
Ionization Energy/Potential: data unavailable
IDLH: 2 mg Hg/m3 (NIOSH, 2023)

AEGLs (Acute Exposure Guideline Levels)

No AEGL information available.

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

No PAC information available.

Regulatory Information

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Mercury Compounds N458 & 313

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names