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MERCURIC OXIDE
ICSC: 0981
Peer-Review Status: 13.03.2001 Validated
Mercury (II) oxide 
CAS #: 21908-53-2 RTECS #: OW8750000
UN #: 1641
EC #: 080-002-00-6
EINECS #: 244-654-7
    Formula: HgO
Molecular mass: 216.6

TYPES OF
HAZARD /
EXPOSURE
ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Not combustible but enhances combustion of other substances. Gives off irritating or toxic fumes (or gases) in a fire.  NO contact with reducing agents.  In case of fire in the surroundings, use appropriate extinguishing media. 
EXPLOSION      
 
EXPOSURE   PREVENT DISPERSION OF DUST! AVOID ALL CONTACT!  IN ALL CASES CONSULT A DOCTOR! 
Inhalation Cough.  Avoid inhalation of dust and mist. Use local exhaust or breathing protection.  Fresh air, rest. Refer for medical attention. 
Skin MAY BE ABSORBED! Redness.  Protective gloves. Protective clothing.  Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention . 
Eyes Redness.  Wear safety goggles or eye protection in combination with breathing protection.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion Abdominal pain. Diarrhoea. Nausea. Vomiting.  Do not eat, drink, or smoke during work. Wash hands before eating.  Rinse mouth. Give one or two glasses of water to drink. Rest. Refer for medical attention . 

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.  Unbreakable packaging.
Put breakable packaging into closed unbreakable container.
Do not transport with food and feedstuffs.
Severe marine pollutant. 
EC Classification
Symbol: T+, N; R: 26/27/28-33-50/53; S: (1/2)-13-28-45-60-61; Note: A 
UN Classification
UN Hazard Class: 6.1; UN Pack Group: II 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-61G64B.  Separated from food and feedstuffs, reducing agents, chlorine and reactive substances. See Chemical Dangers. Keep in the dark. Store in an area without drain or sewer access. Provision to contain effluent from fire extinguishing. 

IMPORTANT DATA
Physical State; Appearance
YELLOW, ORANGE-YELLOW OR RED HEAVY CRYSTALLINE POWDER. 

Physical dangers
 

Chemical dangers
Decomposes above 500°C and on exposure to light. This produces highly toxic fumes including mercury and oxygen. This increases fire hazard. Reacts violently with reducing agents, chlorine, hydrogen peroxide, magnesium (when heated), disulfur dichloride and hydrogen trisulfide. Mixtures with metals and elements such as sulfur and phosphorus are shock-sensitive. 

Occupational exposure limits
TLV (as Hg): 0.025mg/m³ as TWA; (skin); A4 (not classifiable as a human carcinogen); BEI issued; (ACGIH 2008).
MAK: 0.1 mg/m³; Carcinogen category: 3B; Peak limitation category: II(8); Sensitization of skin (SH); BAT issued; (DFG 2008). 

Routes of exposure
The substance can be absorbed into the body by inhalation of its aerosol, through the skin and by ingestion. 

Inhalation risk
Evaporation at 20°C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed. 

Effects of short-term exposure
The substance is irritating to the eyes, skin and respiratory tract. 

Effects of long-term or repeated exposure
The substance may have effects on the kidneys. This may result in kidney impairment. 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Decomposes at 500°C
Density: 11.1 g/cm³
Solubility in water: none 
Bioaccumulation of this chemical may occur in aquatic organisms. It is strongly advised not to let the chemical enter into the environment. 

NOTES
Depending on the degree of exposure, periodic medical examination is indicated.
Do NOT take working clothes home.
Red and Yellow mercuric oxide are common names.
Card has been partially updated in November 2008: see Occupational Exposure Limits, Ingestion First Aid, Storage. 

ADDITIONAL INFORMATION
 

IPCS
International
Programme on
Chemical Safety
WHO ILO EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004-2012
LEGAL NOTICE Neither the EC nor the IPCS nor any person acting on behalf of the EC or the IPCS is responsible for the use which might be made of this information.
    See Also:
       Toxicological Abbreviations