MINERAL DUST

1
MINERAL DUST
2
MINERAL DUSTS

• DEFINITION
• 25 listed in regulations.
• Includes silica, limestone, kaolin clay.
• Silica most significant.
• TYPES OF SILICA
• Quartz (majority of uses).
• Crystobalite.
• Trydimite.

3
SILICA

• COMMON USES
• Glass manufacture.
• Sand blasting.
• Refractory materials.
• Abrasives.
• Contaminant in mining operations.

4

• ABSORPTION
• Inhalation only.
• HEALTH EFFECTS
• Silicosis.
• Risk depends on exposure.
• Mostly chronic (over 10 years).
• Sometimes acute (1-2 years).
• No treatment.
• Can cause death.
• Probable carcinogen (IARC).

5
MINERAL DUSTS

• CONTROLS
• Reduce dust levels.
• Prevent inhalation.
• Apply hierarchy.
• Substitution (garnet, metal shot for sand).
• Engineering controls
• (i) exhaust ventilation
• (ii) dust suppression (water)
• (iii) avoiding use of compressed air (vacuum).
• Personal protection (respirators, overalls).

6
MINERAL DUSTS

• LEGISLATION ( FMD MINERL DUST REGULATION 1989 )
• Main Points
• PEL respirable dust 5mg/m3 (lt 1 silica).
• PEL inspirable dust 10mg/m3 (lt 1 silica).
• PEL quartz 0.1mg/m3.
• Action level 0.05mg/m3.
• Atmospheric monitoring (gt action level).
• Engineering controls.
• Medical examinations record
• Training.

7
Health Surveillance

• Employer shall conduct Medical Examination for
  workers within 3 month they start working.
• Repeat not later than 2 yearly but for those with
  pneumoconiosis, not later than 1 year.
• Shall include
• Occupational, Medical and smoking history
• Chest X ray, Lung Function Test
• Tuberculosis checkup
• Other laboratory test when necessary.