RESULTS AND DISCUSSIONS
4.1 Identified hazards
From the risk assessment process, the lists in the Table 4.0 below are hazards that had been identified during lumber breakdown, but are not limited to those listed below.
Table 4.0 Breakdown of lumber list of hazards.
Hazards Types of hazards
Accumulated wood dust
Safety hazard Exposed sharp blade (Pisau tajam yang
terdedah) Falling object
Moving parts Exposure to noise
Health hazard Exposure to wood
4.2 Safety hazards
A safety hazard is something that can cause a person to be injured or killed (Spellman, 2011).
In this report four (4) safety hazards had been chosen namely, accumulated wood dust, exposed sharp blade, falling object and moving parts.
16 4.2.1 Accumulated wood dust
Accumulated wood dust has the potential to create fire and explosion hazard. Fire and explosion may occur if,
i. housekeeping is poor (accumulation of wood dust (Appendix K and L) is high in the work areas which is a fuel, one of the factors in the fire triangle (Appendix M)).
ii. poor housekeeping method (using air compressor to repel dust will only increase wood dust concentration in the air which can cause explosion hazard if source of heat is present e.g. heat from cigarette, or ignition of lighter);
iii. unsafe act of workers ( e.g. smoking); and
iv. no provision of proper ventilation e.g. general exhaust ventilation or local exhaust ventilation (LEV).
When wood dust accumulates on wood working machinery it acts as an insulator trapping in the heat. If enough heat is formed then the wood dust will ignite causing a fire. If the dust floating in the air is concentrated and a fine dust then a fire can cause an explosion (Spellman, 2011). Based on the accidents reports of this company, there has no any fire or explosion recorded in the sawmill.
4.2.2 Exposed sharp blade (Pisau tajam yang terdedah)
During the operation of band saw, the operators are highly exposed to the sharp blade of band saw. Workers may come in contact with the blade most probably during the feeding of
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lumber to the blade and also the fact that a band saw blade cannot be fully guarded (Appendix P). Thus, the likelihood of workers to come in contact with this hazard is high.
Other reasons on how workers may come in contact with the blade are:
i. poor housekeeping, where workers may slip/trip during feeding the lumber to the blade (point of operation);
ii. unsafe act of the workers (e.g. taking short cuts or do not follow SOPs);
iii. no barricade to keep a distance between the worker and the band saw blade (Appendix N); and
iv. no guarding of the band saw blade (Appendix P).
Even though such occurrence has not been reported but there is high possibility for it to happen as workers are highly exposed to the sharp blade. If the workers come in contact with the blade it may cause lacerations, cuts, abrasion and amputation and even fatality.
4.2.3 Falling object
From the observation made, transferring lumber to the working platform of the band saw requires the workers to lift the lumber at knee to waist height (Appendix I) by using a chain hoist. In which the lumber may fall and crushed the worker’s feet. This can occur if, but not limited to the reasons stated below:
i. the grip of the chain hoist hook is not strong enough to hold the lumber;
ii. the chain breaks due to the usage of defective chain,
18 iii. no inspection on chain before operation; and
iv. no provision or worker do not wear proper PPE (safety boots).
However, based on the accident report of this company such incident has yet to occur but might occur sometime in the future.
4.2.4 Moving parts
Unguarded moving parts of the band saw may cause the worker’s clothing and part of the worker body to be entangled or drawn into the moving parts of the machine (Appendix J and K). From the accident report, one accident had been reported regarding this hazard, in which a worker’s foot was drawn in by the moving parts of the band saw that caused injury to his toes (Appendix R). Such occurrence may occur due to,
i. lack of guarding of the rotating parts;
ii. workers do not follow the proper working dress code; and iii. no provision or workers do not wear proper PPE (safety boots).
Possible injuries from this hazard are cuts, laceration, amputations and abrasions.
19 4.3 Health hazards
Health hazard is hazard that can cause harm to health resulting from exposure of the hazard.
In which in this report exposure to noise and wood dust are chosen as the health hazard that present during work activity
4.3.1 Exposure to noise
The band saw type of noise is continuous which means the noise has noise intensity level between maximum and minimum lower than 3 dB (A). In Factories and Machinery (Noise Exposure) Regulations 1989, Regulation 5 (1) stated that,
No employee shall be exposed to noise level exceeding equivalent continuous sound level of 90dB (A) or exceeding the limits specified in the First Schedule or exceeding the daily noise of unity.
During the breakdown/cutting of lumber the workers are exposed to noise. Noise level that exceeds the PEL of noise exposure level can cause hearing impairment to the affected workers. Appendix E shows the Noise Exposure Monitoring Report of this company and Appendix F shows the working hours of the workers in the breakdown section, and the PEL for noise exposure.
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Workers are exposed to noise are due to but not limited to those listed below:
i. lack of awareness about the danger of high noise level, both the workers as well as supervisor/employer; and
ii. no provision or workers do not wear PPE (hearing protection e.g. ear muffs or ear plug).
4.3.2 Exposure to wood dust
Sawing of wood produces saw dust, thus workers are exposed to high concentration of wood dust during operating the band saw. Both the skin and respiratory system can become sensitized to wood dust. When a worker becomes sensitized to wood dust, he or she can suffer skin irritation (dermatitis), a severe allergic reaction such as asthma, after repeated and long term exposure it may cause cancer to the workers. From the observation of workers operating the band saw it was clear that these workers were exposed to wood dust during the work activity being carried out. Workers are exposed to wood dust are due to but not limited to those listed below:
i. lack of awareness about the danger of wood exposure, both by the supervisor/employer as well as workers;
ii. lack of proper exhaust ventilation; and
iii. no provision or workers do not wear PPE (dust mask)
21 4.4 Determination of hazards risk rating
Table 4.1 Risk rating of each hazard
Work steps Hazard
The HIRARC for breakdown of lumber is shown in Appendix F.
22 4.5 Most critical hazards
From Table 4.1, it shows that the most critical hazards based on score for safety hazard is exposed sharp blade, for health hazard is exposure to wood dust.
4.5.1 Safety hazard
Based on Table 4.1 for safety hazards, exposed sharp blade is the most critical safety hazard because it scored the highest among all the safety hazards. In order to cut a lumber, the operator is required to feed the lumber to the blade. The operator must also keep the lumber flat on the work table/platform. Extreme caution is necessary because the operator has to be near the band saw blade during feeding of the lumber to ensure that the lumber is properly cut (Appendix O), as a band saw blade cannot be fully guarded, simple mistake like trip or slip during the feeding of the lumber may cause the worker to come in contact with the blade.
And from the size of the band saw blade, serious injury or even death can happen if the contact with the blade is major.
4.5.2 Health hazard
Based on Table 4.1, exposure to wood dust scored the highest risk rating for health hazard.
Wood dust consists of tiny particles of wood produced during the sawing of wood. From the observation made workers are exposed to high concentration of wood dust during the breakdown of lumber.
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Exposure to wood dust occurs primarily through skin contact and inhalation as the workers go about sawing activities. The dust settles on skin and inhaled as it floats around the saw mill. If the dust is thick enough it can be ingested through the mouth.
Exposure to wood dust may cause health problems. Negative health effects associated with wood dust exposure include dermatitis and/or allergic respiratory effects. When a worker becomes sensitized to wood dust, he or she can suffer an allergic reaction after repeated exposures, such as asthma.
Cancers also have been associated with wood dust exposure. The National Institute for Occupational Safety and Health (NIOSH) considers both hardwood and softwood dust to be potentially carcinogenic to human. The three types of cancers associated with wood dust exposure are nasal and sinus cavity cancer, lung and other cancers, and Hodgkin’s disease (a type of lymphoma which is a cancer originating from white blood cells called lymphocytes) (Spiers, 1969).
The wood and cancers relationship was studied by Milham (1974), who conducted a mortality study involving the American Federation of Labor and Congress of Industrial Organizations (AFL-CIO) United Brotherhood of Carpenters and Joiners of America. This study support the hypothesis that wood contains carcinogen agent. In which one of the findings was that excess leukaemia lymphoma group cancers in millwrights, mill workers, and lumber and sawmill workers.
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Table 4.2 shows that it has been stated in the Occupational Safety and Health (Notification of Accident, Dangerous Occurrence, Occupational Poisoning and Occupational Disease) Regulations that exposure to wood dust can cause cancer.
Table 4.2 Occupational diseases caused by wood dust. Adapted from Third Schedule of Occupational Safety and Health (Notification of Accident, Dangerous Occurrence, Occupational Poisoning and Occupational Disease) Regulations 2004 (NIOSH, 2011).
Description of occupational poisoning or
disease Nature of activity/occupation
OTHER CONDITIONS 29. Cancer caused by –
(p) Wood dust
Any occupation involving –
the use or handling of; or exposure to, wood dust arising from the manufacture of wood
products.