whims hazardous material- Silica presented at Lambton College

1. Overview
 What are designated substances?
 Definition and uses of Silica.
 What are the employer
responsibilities in handling of Silica?
 What are exposure limits of Silica?
 What are the elements of control
program?
Submitted by :
Manjot Kaur (718546)
Rajjat Chanotra (703193)

2. Designated substances
 According to the Health and Safety Act , a toxic substances are known as
“designated substances”, as these substances are particularly hazardous to
health and safety of workers.
 For instance – Benzene, Arsenic ,Lead ,Silica, Asbestos etcetera.
 These chemicals can cause serious Illness or injury.
 They can enter in the body through various routes,
for example – Skin contact , Inhalation ,Ingestion, Eye
Contact etcetera.

3. Silica
 Silica is the most abundant
mineral in the earth's crust.
 Its another name is silicon
dioxide.
 It is widely used in glass,
foundries, construction,
ceramics, and the chemical
industry.
 Silica sand is used in water
filtration and agriculture.

4. What is so hazardous about Silica?
 Two forms of Silica, crystalline and amorphous.
 Crystalline silica (2-3 μm or smaller) is hazardous and is
commonly found in the form of quartz in most rock types.
 Repeated exposure to crystalline silica dust for 1-2 years can
be carcinogenic.
 It can also cause Silicosis.
 Silicosis is not treatable

5. Health effects
 Silicosis
Silica is mainly hazardous in its dust form
and for long term exposure (1 year), it scars
the lungs and causes Silicosis( blue colour)
 Lung cancer
Exposure over 10-20 years
 Chronic Obstructive Pulmonary Disease
Prolonged exposure up to( 30- 40 years)

6. Parameters to be followed during use of
silica
 Avoid generation of dust
 Keep container tightly closed and dry
 Work with Silica in a fume hood or a
well ventilated environment.

7. Employer responsibilities
 Proper label
 Provide education and training to the workers.
 Make sure appropriate control measures are in place
to protect the health and safety of workers
 Participate in identifying and eliminating hazards.

8.  Maintain written records of training (e.g. proper use of respirators), respirator fit-
test results, exposure monitoring results, and inspections (of equipment, PPE, and
work methods and practices).
 Conduct exposure monitoring as required and ensure that workers are informed of
exposure measurements.
 Ensure that health assessments are performed in accordance with applicable health
and safety legislation requirements.
 Coordinate work with other employers to ensure a healthy and safe work
environment.

9. Exposure limits
 TWA, is the maximum airborne concentration to which a worker may be
exposed in a normal 8-hour day, 40-hour work week, to which nearly all
workers may be repeated exposed over a working lifetime, without adverse
effects. So for Silica is :-
SILICA TWA
Silica, Crystalline 0.05 mg/m3
Quartz 0.10 mg/m3
Cristobalite 0.05 mg/m3
Silica fume 2 mg/m
3
Silica fused 0.1mg/m
3

10. Control program
Combination of controls must be most suitable.
Control program must include:
• engineering controls,
• work practices
• and hygiene facilities that control worker’s exposure

11. Control program
 ENGINEERING CONTROLS
o Emissions at their source
o Equipment Selection
o Ventilation
 WORK PRACTICES AND PROCEDURES
Procedures must ensure the safe handling, use and disposal of
materials containing crystalline free silica.
 Housekeeping :vacuum cleaning – wet sweeping
– no air blowing

12. Control program
 AIR MONITORING
Companies must include planned air monitoring to reduce worker exposure.
 MEDICAL SURVEILLANCE AND EXAMINATIONS
Health of workers can be protected by :
 Clinical tests
 Evaluating the effect of silica on workers
 Periodic medical examinations
 PERSONAL HYGIENE FACILITIES AND PRACTICE
 Washing Facilities
 Eating Facilities