Mercury oxide (Hg2O)

H315: Causes skin irritation [Warning Skin corrosion/irritation]

H317: May cause an allergic skin reaction [Warning Sensitization, Skin]

H320: Causes eye irritation [Warning Serious eye damage/eye irritation]

H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]

H361: Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]

H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]

H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

P203, P260, P261, P264, P264+P265, P270, P271, P272, P280, P302+P352, P304+P340, P305+P351+P338, P308+P316, P318, P319, P321, P332+P317, P333+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

Refer to the "General First Aid" section. (ERG, 2024)

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Water spray, fog or regular foam. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal. Avoid aiming straight or solid streams directly onto the product.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

Excerpt from ERG Guide 151 [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 tank car or highway tank 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, 2024)

Mercury spills should be cleaned up immediately by use of a special vacuum cleaner. Then the area should be washed with a dilute calcium sulfide solution. Small quantities of mercury can be picked up by mixing with copper metal granules. ... /Mercury/

Mercury removal from waste water can be accomplished by these processes: BMS process; Chlorine is added to the waste water, oxidizing any mercury present to the ionic state. The BMS adsorbent (an activated carbon concentrate of sulfur cmpd on its surface) is used to collect ionic mercury. The spent adsorbent is then distilled to recover the mercury, leaving a carbon residue for reuse or disposal. TMR IMAC Process; Waste water is fed into a reactor, whereby a slight excess of chlorine is maintained, oxidizing any mercury present to ionic mercury. The liquid is then passed through the TMR IMAC ion-exchange resin where mercury ions are adsorbed. The mercury is then stripped from the spent resin with hydrochloric acid solution. /Mercury cmpds/

SPILLED MERCURY CMPD OR SOLN CAN BE CLEANED UP BY ANY METHOD THAT DOES NOT CAUSE EXCESSIVE AIRBORNE CONTAMINATION OR SKIN CONTACT. /MERCURY COMPOUNDS/

1) Ventilate area of spill. 2) Collect spilled material for reclamation using commercially available mercury vapor depressants or specialized vacuum cleaners. /Inorganic mercury/

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number D009, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

If material not involved in fire: Keep material out of water sources and sewers.

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 is anticipated, wear appropriate chemical protective clothing.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers.

Preventative measure: adequate ventilation; careful attention to good housekeeping, e.g., avoidance of spills, and prompt and proper cleaning if a spill occurs; all containers of mercury and its compounds should be kept tightly closed; should be washed on a regular basis with dilute calcium sulfide solution or other suitable reactant; floors should be nonporous; all workers directly involved in the plant operation should shower thoroughly each day before leaving. /Mercury compounds/

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Cover with plastic sheet to prevent spreading. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. For solids, prevent dust cloud and avoid inhalation of dust. (ERG, 2024)

PROTECT FROM LIGHT.

0.02 [mg/m3], as Hg, inhalable fraction[German Research Foundation (DFG)]

0.0046 [ppm]

0.25 [ppm]

0.50 [ppm]

0.1 [mg/m3], as Hg

10 mg Hg/m3 (NIOSH, 2024)

10.0 [mg/m3], as Hg

10 mg/cu m (as Hg) /Mercury cmpd (except (organo) alkyl compounds (as Hg)/

0.02 [mg/m3], as Hg

8 hr Time Weighted Avg (TWA): 0.025 mg/cu m, skin. /Mercury, elemental and inorganic forms, as Hg/

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded. /Mercury, elemental and inorganic forms, as Hg/

A4: Not classifiable as a human carcinogen. /Mercury, elemental and inorganic forms, as Hg/

Biological Exposure Index (BEI): Determinant: total inorganic mercury in urine; Sampling Time: Prior to shift; BEI:35 ug/g creatinine. The determinant may be present in biological specimens collected from subjects who have not been occupationally exposed, at a concentration which could affect interpretation of the result. Such background concentrations are incorporated in the BEI value. /Mercury/

Biological Exposure Index (BEI): Determinant: total inorganic mercury in blood; Sampling Time: end of shift at end of workweek; BEI: 15 ug/L. The determinant may be present in biological specimens collected from subjects who have not been occupationally exposed, at a concentration which could affect interpretation of the result. Such background concentrations are incorporated in the BEI value. /Mercury/

Chronic Inhalation: 0.0002 mg/m3 (L134)

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE. Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)

BUREAU OF MINES APPROVED AIRLINE RESPIRATOR; IMPERVIOUS SUIT; APPROPRIATE EYE PROTECTION.

Personnel protection: ... Wear appropriate chemical protective gloves, boots and goggles. ... Wear positive pressure self-contained breathing apparatus when fighting fires involving this material.

Mercury oxide appears as black or brownish-black powder. Not a true compound but rather an intimate mixture of metallic mercury and mercuric oxide. Insoluble in water and denser than water (density 9.8 g / cm3). Hence sinks in water.

Black solid; [Hawley] Brown to black odorless powder; [MSDSonline]

Black or brownish-black powder

100 °C (decomposes to elemental mercury)

Insol in water; sol in nitric acid

Sol in acids

9.8 @25 °C

When heated to decomposition ... emits highly toxic fumes of /mercury/.

75.6 DYNES/CU M

Hydrochloric acid converts it into calomel.

Metals -> Mercury Compounds, Inorganic

Insoluble in water.

Metals, Less Reactive

Oxidizing Agents, Weak

Mixtures of MERCURY OXIDE with barium oxide react vigorously with hydrogen sulfide in air. Explosions may result [Mellor 10:140. 1946-47]. Dissolves in nitric acid. Reacts with hydrochloric acid to give insoluble mercurous chloride (calomel). Contact of the metal oxide caused the explosive decomposition of hydrogen peroxide [Bretherick 5th ed., 1995]. Mixtures with phosphorus or sulfur explode by impact and friction respectively, [Mellor, 1940, Vol. 4, 77].

MOLTEN SODIUM OR POTASSIUM DECOMPOSES MERCUROUS OXIDE WITH SLIGHT EXPLOSION.

MIXTURE /OF MERCUROUS OXIDE & HYDROGEN PEROXIDE/ REACTS WITH EXPLOSIVE VIOLENCE.

MIXTURES OF BARIUM OXIDE WITH MERCUROUS OR NICKEL OXIDE ALSO REACT VIGOROUSLY WITH HYDROGEN SULFIDE IN AIR & VIVID INCANDESCENCE OR EXPLOSIONS MAY RESULT.

Interaction of /mercury(I) oxide/ with molten potassium or sodium is accompanied by a brilliant light and a light explosion.

MIXTURE OF /MERCUROUS OXIDE & SULFUR/ PULVERIZED MATERIALS WILL IGNITE FROM LIGHT IMPACT.

High-affinity binding of the divalent mercuric ion to thiol or sulfhydryl groups of proteins is believed to be the major mechanism for the activity of mercury. Through alterations in intracellular thiol status, mercury can promote oxidative stress, lipid peroxidation, mitochondrial dysfunction, and changes in heme metabolism. Mercury is known to bind to microsomal and mitochondrial enzymes, resulting in cell injury and death. For example, mercury is known to inhibit aquaporins, halting water flow across the cell membrane. It also inhibits the protein LCK, which causes decreased T-cell signalling and immune system depression. Mercury is also believed to inhibit neuronal excitability by acting on the postsynaptic neuronal membrane. It also affects the nervous system by inhibiting protein kinase C and alkaline phosphatase, which impairs brain microvascular formation and function, as well as alters the blood-brain barrier. Mercury also produces an autoimmune response, likely by modification of major histocompatibility complex (MHC) class II molecules, self peptides, T-cell receptors, or cell-surface adhesion molecules. (L7, A8, A25, A26)

A4: Not classifiable as a human carcinogen. /Mercury, elemental and inorganic forms, as Hg/

3, not classifiable as to its carcinogenicity to humans. (L135)

Mercury mainly affects the nervous system. Exposure to high levels of metallic, inorganic, or organic mercury can permanently damage the brain, kidneys, and developing fetus. Effects on brain functioning may result in irritability, shyness, tremors, changes in vision or hearing, and memory problems. Acrodynia, a type of mercury poisoning in children, is characterized by pain and pink discoloration of the hands and feet. Mercury poisoning can also cause Hunter-Russell syndrome and Minamata disease. (L7)

Oral (L7) ; inhalation (L7) ; dermal (L7)

Common symptoms include peripheral neuropathy (presenting as paresthesia or itching, burning or pain), skin discoloration (pink cheeks, fingertips and toes), edema (swelling), and desquamation (dead skin peels off in layers). (A5)

Neurotoxin - Sensorimotor

Nephrotoxin - The chemical is potentially toxic to the kidneys in the occupational setting.

Mercury poisoning is treated by immediate decontamination and chelation therapy using DMSA, DMPS, DPCN, or dimercaprol. (A7)

IN MOIST AIR, MERCURY (HG) MAY OXIDIZE SLOWLY, FORMING A FILM OF MERCUROUS OXIDE (HG2O). IN GENERAL, HOWEVER, THE FILM THAT FORMS IS THAT OF THE OXIDES OF TRACES OF CONTAINED IMPURITIES.

IN MOIST AIR, MERCURY (HG) MAY OXIDIZE SLOWLY, FORMING A FILM OF MERCUROUS OXIDE (HG2O). IN GENERAL, HOWEVER, THE FILM THAT FORMS IS THAT OF THE OXIDES OF TRACES OF CONTAINED IMPURITIES.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number D009, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

/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 oxide/

/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 oxide/

/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 oxide/

/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 oxide/

For more DOT Emergency Guidelines (Complete) data for MERCUROUS OXIDE (8 total), please visit the HSDB record page.

UN 1641; Mercurous oxide

IMO 6.1; Mercury oxide

49 232 64; Mercurous oxide, black, solid

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.