Risk Assessment Form
#11 Activity-Based Risk Assessment for Concrete Mixing and Application at the Duplex Projects
Inventory of Work Activities
Company: PNH Resources LTD PTE
No.
1
Process Description
Mixing of materials to make mortar for use inside of duplex
2
Physical effort required to make the concrete slurry
3
Trowelling material onto surfaces inside duplex structure
4
Working under stress from exposure to ambient heat.
25 October 2010
Work Activities
Handling 50 kg (110 lb) Mixing dirt, cement and water to make mortar
slurry
Moving dirt with wheel barrow and shovel, lifting concrete bags as
needed, mixing materials with shovel and hoe
Material from the slurry pile is placed in small buckets where it is
transferred to the area inside the duplex it will be applied. Material is then
troweled onto surface as needed.
All work outside in Singapore is considered to place workers at risk of
injury from heat.
Risk Assessment Form
Activity-Based Risk Assessment Form
Company:
Process/Location:
PNH RESOURCES PTE LTD
Duplex Renovation Projects – To be used as
reference for all similar projects
Mr. Lee Wilson
Alice Wilson
Senior Safety Manager
PWD
25 October 2010
25 October 2010
Approved by:
(Name, designation)
(Date)
1.
Hazard Identification
1b
1c
1d
2a
No
Work Activity
Hazard
Possible
Accident/
Ill Health &
Persons at Risk
Individual(s)
mixing these
materials and
working with
the “Portland
Cement” in a
dry state.
Existing Risk
Control
(if any)
Mixing different
components
together to make
concrete mixture for
application inside of
duplexes. 1-2
workers involved
with this process.
Workers use two
wheel barrows full of
dirt and mix material
on cement patio of
duplex. To the dirt
approximately 30 lbs
Crystalline
Silica
*Note: Long
term chronic
occupational
exposure to these
materials can
result in lung
scarring known as
silicosis
Last Review
Date:
11 April 2011
2. Risk Evaluation
1a
1
Conducted by: (Names, designations) (Date)
Except for possibly
a 10 minute
exposure to dry
cement material
outdoors, the
cement is worked
in a wet state and
exposure is not
characterized as
chronic
occupational
exposure.
Lee Wilson
Senior Safety Manager
25 October 2010
Next
01 November
Review
2011 – (Duplex
Date:
project should
be complete by
this date, but
the AHA will be
maintained for
historical
perspective.)
3. Risk Control
2b
2c
2d
Severity
Liklihood
Risk Level
Minor
Occas.
Low
3a
3b
Additional Risk Control
Action Officer
Designation
Workers are scheduled to receive
training on the hazards of
working with dry cement and
most notably materials containing
crystalline silica. We are in the
process of providing workers with
“humanitarian” respiratory
protection for the brief periods
they may be exposed to dry
cement material.
Safety
Manager
(13 kg) of cement is
added for an
approximate mix of
between 7-10 parts
dirt per one part
cement. The
materials are mixed
and shaped into a
cone and water is
added. The mixture
is blended until it is a
slurry and then it is
scooped into small
work pails as needed
to be applied to
various surfaces
inside of the duplex.
Sight Hazard
Musculoskeletal
- Work crew
assigned to mix
and apply
concrete slurry
Individuals
putting these
components
together are
at risk from
exposure to
dirt and
cement when
mixing these
materials
Training on
proper lifting
techniques,
knowing
individual
limitations and
Workers receive
training on sight
conservation and
all PNH employees
are issued eye
protection which
is inspected every
4-6 weeks and is
replaced at
company costs if
equipment is
deteriorated from
normal wear and
tear. Equipment
that is
deteriorated from
misuse or neglect
must be replaced
by the worker.
Moderate
Minor
Remote
Low
Part of the Sight Conservation
Training includes the use of eye
wash station and the practice that
anytime foreign objects are
introduced into the eye, the eye
is flushed for a minimum of 15
minutes. A Haws model 7500 eye
wash station is available and
maintained at this job site.
Safety
Manager
Occas.
Medium
Ensure that tool
box training is
used to alert
personnel of risks
when moving
heavy materials
The applicable training for this
project shall be re-enforced prior
to commencing a new phase of
this same type of work.
Safety
Manager
At risk for strains,
sprains and other
injuries
associated with
lifting and
carrying
materials,
working with
wheel barrows,
shoveling and
hoeing to mix
materials.
2
Heat Stress
Note: The
cement comes in
50 kg (110 lb
bags). These
workers have
frequently been
observed
manually hauling
these bags
around the
worksite. To date
there have been
no reports of
musculoskeletal
injuries from this
crew.
Heat Cramps
Heat Rash
Heat Syncope
Heat Exhaustion*
Heat Stroke**
*If not treated
properly can
progress to heat
stroke.
**Life
Threatening and
good
supervision
and the
importance of
using good lifting
techniques.
Workers should
also be advised
that the use of
back support
equipment is
often
counterproductive
in that studies
have shown that
this type of
equipment really
does not protect
against back
injuries and may
actually place the
worker at greater
risk by giving a
false sense of
security
Personnel
performing
work outdoors
in Singapore
Tool Box Talk
Training
concerning heat
stress, clean
drinking water at
all job sites,
sufficient rest
periods for
workers in
accordance with
NAVMED P-5010
and Ministry of
Manpower
Min
Occas.
Low
Continue emphasis on heat
injuries whenever safety stand
downs, events, tool box talks etc..
are planned. Ensure that drinking
water is always available for
crews working in heat stress
conditions. Ensure that sub
contractors receive training on
the Heat Stress Program observed
at the Sembawang Compound
including the use of colored flags.
Please refer to the chart provided
Safety
Manager
is a real medical
emergency.
Definitive
medical
assistance must
be summoned.
at the bottom of this document
for additional information
regarding heat monitoring on this
compound
This information shall pertain to
all of the activities conducted
outdoors during this project.
Heat Stress
(Color)
Green
Yellow
Red
Black
Condition
Calculations:
WBGT = WB X 0.7 + DB X 0.1 + GT X 0.2
Meter calibration should be manually verified every 3 months. Manual calculation must be 0.2 degrees + the meter WBGT readout
I
II
III
IV
Heat Stress WBGT
Temperature
27.78-29.39 (82-84.9F)
29.44-31.06 (85-87.9F)
31.11-32.17 (88-89.9F)
Above 32.22 (90F)
Recommendations
Activity Level
Discretion is required when planning heavy exercise for acclimatized personnel.
Strenuous exercise and activity for new and un-acclimatized personnel during the first 30 days of heat exposure.
Strenuous exercise should be curtailed for personnel with less than 12 weeks of training in hot weather.
Physical training and exercise should be curtailed for all personnel (operational commitments excluded).
Heat stroke likelihood is high under conditions of high exertion.