Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

MAGNESIUM SILICATE HYDRATE

NFPA

PRODUCT USE

Technical grade is used as extender, filler pigment in paint, rubber, ink, coated papers
and in plastics. Used in dry and liquid lubricants. Filter aid. Should not be confused
with other forms of magnesium silicate which include magnesium orthosilicate, magnesium
metasilicate, serpentine (antigorite and chrysotile forms). Talc and asbestos are also
forms of magnesium silicate.

SYNONYMS

H2-Mg2-O9-Si3, Mg2O8Si3.H2O, "basic magnesium silicate", "magnesium trisilicate hydrated",
"silicic acid, magnesium salt", "hydrous magnesium silicate"

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

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 to be non toxic.  Considered an unlikely route of entry in commercial/industrial environments.  

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.  Not considered an irritant through normal use.  The material may cause skin irritation after prolonged or repeated exposure and may produce on contact skin redness, swelling, the production of vesicles, scaling and thickening of the skin.  

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

  Principal routes of exposure are usually by inhalation of generated dust and eye contact.  The material is harmful if inhaled.  Inhalation of dust is an acute and chronic hazard.  The overuse of of the congener product, talc, in nursing infants has  resulted in pulmonary oedema, pneumonia and death within hours of inhaling  talcum powder. The powder dries the mucous membranes of the bronchioles,  disrupts pulmonary clearance, clogs smaller airways. Victims display  wheezing, rapid or difficult breathing, increased pulse, cyanosis, fever.  Mild exposure may cause relatively minor inflammatory lung disease.  Long term exposure may show wheezing, weakness, productive cough, limited  chest expansion, scattered rales, cyanosis.  Long term exposure to high dust concentrations may cause changes in lung function i.e. pneumoconiosis; caused by particles less than 0.5 micron penetrating and remaining in the lung. Prime symptom is breathlessness; lung shadows show on X-ray.  Repeated exposures, in an occupational setting, to high levels of fine- divided dusts may produce a condition known as pneumoconiosis which is the lodgement of any inhaled dusts in the lung irrespective of the effect. This is particularly true when a significant number of particles less than 0.5 microns (1/50,000 inch), are present. Lung shadows are seen in the X-ray. Symptoms of pneumoconiosis may include a progressive dry cough, shortness of breath on exertion, increased chest expansion, weakness and weight loss. As the disease progresses the cough produces a stringy mucous, vital capacity decreases further and shortness of breath becomes more severe. Pneumoconiosis is the accumulation of dusts in the lungs and the tissue reaction in its presence. It is further classified as being of noncollagenous or collagenous types. Noncollagenous pneumoconiosis, the benign form, is identified by minimal stromal reaction, consists mainly of reticulin fibres, an intact alveolar architecture and is potentially reversible.