5. Health Effects

Sodium metasilicates are alkaline, meaning they have high pH.  The pH typically ranges from 12.4 to 12.7.  This property makes sodium metasilicate irritating to the skin, mucous membranes and eyes.
Contact with the eyes can cause severe irritation, pain, and corneal burns possibly leading to blindness.  Direct contact with the skin may cause irritation.  Inhaling dusts of sodium metasilicates may result in irritation of the respiratory tract with symptoms such as coughing, choking and pain.  Ingesting sodium metasilicate is unlikely; however, if ingested, it may cause pain and burns of the esophagus and gastrointestinal tract with vomiting, nausea, and diarrhea.
There are no known chronic hazards associated with sodium metasilicates.  They are not classified as carcinogens by the National Toxicology Program (NTP), the International Agency for Research on Cancer (IARC), or the Occupational Safety and Health Administration (OSHA).
 

6. Environmental Effects

If released to water, sodium metasilicate will initially sink, then mix with water.  Because sodium metasilicates have a high pH, they can be acutely toxic.  Sodium metasilicates have exhibited moderate toxicity to aquatic organisms and slight toxicity to terrestrials organisms.  The diluted material will decompose to become silica that is no different that natural dissolved silica.  Silica does not bioconcentrate up the food chain
 

7. Exposure

Sodium metasilicate is corrosive to the skin and eyes.  The most likely ways exposures could occur are:
• Worker exposure – Exposure could occur in the manufacturing facility or in industrial facilities that use sodium metasilicates.  When exposures occur, they are     typically skin or eye exposures.  Good industrial hygiene practices and personal protective equipment will minimize the risk of exposure.

• Consumer exposure –   OxyChem does not sell sodium metasilicate in retail stores, although it may be an ingredient in some consumer products.  

• Releases – If a spill occurs, emergency personnel should wear protective equipment to minimize exposures.

8.  Recommended Risk Management Measures

 Sodium metasilicates are non-flammable, non-explosive, and non-toxic. They are, however, alkaline materials and pose hazards to the skin and eyes. The        physiological effects of contact range from causing irritation to causing chemical burns.

Sodium metasilicate should be handled with care. If there is any risk of eye contact, goggles should be worn. It is also recommended that appropriate protective clothing and gloves be worn to prevent metasilicate solutions from coming into contact with the skin.  
 

Prior to using any sodium metasilicate product, carefully read and comprehend the Material Safety Data Sheet for the product being used.

9.  Product Stewardship Programs

A product handbook prepared by OxyChem is available for sodium silicate products including sodium metasilicate.  The handbook includes technical data regarding the products as well as more detailed information about the manufacturing process and product uses.  In addition, specific information for unloading tank cars, tank trucks, and handling drums of material is provided.  Other topics include recommendations on storage and equipment. 
 

10.  Regulatory Compliance Information

Sodium metasilicate CAS No.: 6834-92-0,
Linear Formula: Na2SiO3, Empirical Formula: Na2O3Si
Formula Weight : 122.06
Form-18 Mesh Granular