Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

MAGNESITE

STATEMENT OF HAZARDOUS NATURE

Not considered a hazardous substance according to OSHA 29 CFR 1910.1200.

NFPA

PRODUCT USE

Used to make various grades of magnesium oxide, to produce carbon dioxide, refractories,
as an additive to make free- running table salt, as a bulking compound in powder
formulations, and as an antacid.

SYNONYMS

MgCO3, "crystalline magnesium carbonate", "magnesium (II) carbonate (1:1)", "magnesium
(II) carbonate (1:1)", "carbonic acid magnesium salt", "Magnesia Alba", "magnesium
carbonicum", "magnesium subcarbonicum", "C.I. 7713", hydromagnesite, "magnesite M65",
"light magnesium carbonate", "Mag Carb Pulv.", "Stan-Mag magnesium carbonate", dianase,
grog

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

None

EMERGENCY OVERVIEW

RISK

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  Although ingestion is not thought to produce harmful effects, the material may still be damaging to the health of the individual following ingestion, especially where pre-  existing organ (e.g. liver, kidney) damage is evident. Present definitions of harmful or toxic substances are generally based on doses producing mortality (death) rather than those producing morbidity (disease, ill-health). Gastrointestinal tract discomfort may produce nausea and vomiting. In an occupational setting however, ingestion of insignificant quantities is not thought to be cause for concern.  Considered an unlikely route of entry in commercial/industrial environments.  Considered to be non toxic.  

EYE

  Although the material is not thought to be an irritant, direct contact with the eye may produce transient discomfort characterized by tearing or conjunctival redness (as with windburn).  

SKIN

  The material is not thought to produce adverse health effects or skin irritation following contact (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable gloves be used in an occupational setting.  and may cause drying of the skin.  if exposure is prolonged.  

INHALED

  The material is not thought to produce adverse health effects or irritation of the respiratory tract (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable control measures be used in an occupational setting.  Persons with impaired respiratory function, airway diseases and conditions such as emphysema or chronic bronchitis, may incur further disability if excessive concentrations of particulate are inhaled.  

CHRONIC HEALTH EFFECTS

  Considered to be non toxic.  As with any chemical product, contact with unprotected bare skin; inhalation of vapor, mist or dust in work place atmosphere; or ingestion in any form, should be avoided by observing good occupational work practice.  Principal routes of exposure are usually by.  inhalation of generated dust and skin contact.  with the material.  Prolonged inhalation of high concentrations of magnesite (magnesium  carbonate) dust caused pulmonary deposition and retention. Roasted magnesite  (magnesium oxide) produced a greater degree of fibrosis than did crude  magnesite. No cases of human systemic poisoning due to exposure to  magnesite have been recorded. Pneumoconiosis was found in about 2% of  workers exposed to high concentrations of dust from crude or roasted  magnesite that also contained 1-3% silicon dioxide. Exposure periods ranged  from 6-20 years. This condition occurred mainly in workers exposed to  roasted (calcined) magnesite. The pneumoconiosis appeared to be "benign"  and was often associated with chronic bronchitis and lung emphysema.  In other reports the severity of the pneumoconiosis was associated with  the crystalline silica content of the dust or in a case of magnesium  carbonate used in insulating materials, the severity of the disease  depended on the asbestos content.  Complaints of coughing are rare amongst magnesite workers, and more  frequent among dianase and grog (crushed refractory materials) workers.  Airborne dust concentrations were lowest in dianase facilities but  crystalline silica was high. Chronic bronchitis then, appears to increase  where concentrations of crystalline silica are highest.