ASBESTOS

1
ASBESTOS

• MINERALOGY
• Fibrous silicates.
• Thin crystalline fibres.
• Split longitudinally.
• Common types
• (i) chrysotile (white) - serpentine
• (ii) amosite (brown)
• (iii) crocidolite (blue)
• (iv) tremolite
• (v) actinolite
• (vi) anthophyllite.

2
ASBESTOS

• PROPERTIES
• Tensile Strength.
• Heat resistant.
• Chemical Resistant.
• Can be woven.
• Insulating properties.

3
ASBESTOS

• USES
• More than 3,000.
• Friction products (brake, clutch).
• Building products (asbestos cement).
• Insulation (fire).
• Fabric (blankets, gloves etc).

4
ASBESTOS

• ASBESTOS RELATED DISEASES
• Asbestosis
• scarring of lungs
• reduced lung function
• can cause death
• high concentration and time.

5
ASBESTOS

• ASBESTOS RELATED DISEASES
• Pleural Plaques
• thickening of pleura
• not fatal.
• Mesothelioma

6
ASBESTOS RELATED DISEASES

• Mesothelioma
• cancer of pleura or peritoneum
• rare, most associated with asbestos
• invariably fatal
• associated with low exposures as well
• latency 15-50 years
• blue and brown most potent.

7
ASBESTOS

• ASBESTOS RELATED DISEASES
• Lung Cancer ( Bronchial carcinoma )
• mainly associated with high exposures
• all types of asbestos
• smoking greatly increases risk.
• Multiplied risk ( smoking x asbestos )

8
CONTROLS

• Eliminate ( do not use at all )
• Substitute (replacements available for most
  products).
• Enclosure (buildings and industrial processes).
• Isolation (often possible in buildings).
• Engineering (ventilation commonly used).
• Work Process ( to reduce exposure by rotation)
• Protective equipment (respirators).

9
ASBESTOS

• LEGISLATION
• ( FMD Asbestos Process Regulation, 1986 )
• PEL 1 f/ml. of air
• Exhaust equipment.
• Protective equipment.( clothing/resp)
• Medical examinations. ( at least 2 yrs )
• Monitoring-personal ( lt 3 mthly )
• Training.