Incidents involving Hazardous Chemicals in Research Laboratories

26 Sep 2012

Recently, there were three serious laboratory incidents involving hazardous chemicals occurred in research laboratories of local institutes of higher learning (IHL) – one involved mixing of incompatible chemicals resulting in an explosion, another involved a highly flammable organic solvent causing a fire and the third was spillages of chemical from a ruptured container.

Explosion from Incompatible Chemical Reactions

The first case involved an explosion of a glass bottle containing chemical waste in a cargo lift of a laboratory building. There were two passengers in the lift when the accident happened. One of them, a research assistant, suffered from acid burns to his thighs, arms and eyes, and cuts from the shattered glass pieces. The other passenger, a senior research scientist, suffered from eyes and skin irritation. Investigation revealed that the research assistant had mixed unknown chemical wastes in one of the waste chemical bottles prior to transporting them to the basement storage room via the cargo lift. The incident was a result of incompatible chemicals being mixed causing pressure to build up in the bottle and resulting in an explosion.

Flash Fire from a Flammable Chemical
The second case involved a flash fire occurred in a science laboratory of an IHL. A research assistant suffered second degree burns on one of his hands and minor burns on his cheek. The incident occurred when the research assistant was in the midst of quenching the apparatus used for preparing a strong oxidising agent in a fume cupboard. The fire occurred when he was adding a highly flammable isopropyl alcohol (IPA) into the apparatus without cooling it in an ice bath. The incident was likely caused by the exothermic reaction between the oxidising agent and IPA which ignited the flammable vapour in the apparatus.

Chemical Spill from a Ruptured Waste Container
The third case involved a chemical spilt from a ruptured carboy in a clean room of a research institute. The chemicals were discharged from the wet scrubber system of a Metalorganic Chemical Vapor Deposition unit into 20L-carboys in preparation for the relocation of the unit. During the transfer of the filled carboys to the holding area by the waste collector, a breach in one of the carboys occurred, resulting in a spill and release of pungent gases. All staffs were evacuated and no person was injured . The incident was likely caused by the poor integrity of the carboy (due to wear and tear) and / or reaction of the chemicals (collected from the scrubber system) with the residual chemical in the carboy resulting in gas released in the carboy.

Other findings of the above cases include:

1) Inadequate labeling of chemical waste bottles
2) Insufficient training and supervision provided for persons carrying out the work
3) A risk assessment was not conducted before the start of the work
4) Safe work procedures were not implemented
5) Personal protective appliances were not worn during work
Recommendations*

Stakeholders performing similar work activity can undertake control measures such as the following to prevent a recurrence:

Risk assessment

1. Prior to work, conduct a proper risk assessment to identify all hazards and the risks involved. Control measures and safe work procedures must be established and implemented.

2. Safe work procedures and precautions have to be strictly adhered to when handling hazardous substances such as flammable or corrosive chemicals and oxidising agents.Hazard communication and work practices

3. Ensure all chemical containers and waste bottles are properly labelled, stating clearly the identity of the content, hazards nature and precautionary measures whenever possible.

4. Incompatible chemicals like acid and strong oxidisers should not be mixed. Refer to the safety data sheets for any incompatible reactions.

5. Reusing of chemical containers should be avoided as far as possible. However, if containers are reused, they should be cleaned adequately before used to minimize contaminations and undesirable reactions.

6. Stakeholders should maintain good housekeeping in the laboratories. Workbenches and fume hoods should not be cluttered. Aisles and exits should be free from obstructions.

Training and Education

7. All persons involved in the work must be adequately trained and informed of the risks involved and the safety precautions to take.

8. All persons who are not involved in the work should not be allowed near areas where the work is carried out.
Personal protection and supervision.

9. Suitable personal protection equipment should be provided and worn at all time when performing the work.

10. Adequate supervision should be provided to ensure the work is carried out in a safe manner. Supervisors should be responsible to ensure safe work procedures are adhered to. Engineering Control11. Fume hoods should be used when working with volatile chemicals or when airborne contaminants are generated. Guidelines on the proper usage of fume hoods should be developed and make available to all fume hoods users.

Figure 1: Photograph taken after flash fire in the fume hood.

Figure 2: Photograph of the ruptured carboy.

Useful Resources

1. Laboratory Safety Guidance, Occupational Safety and Health Administration (OSHA), please click HERE.

2. Laboratory Safety Chemical Fume Hoods, Occupational Safety and Health Administration(OSHA), please click HERE.

3. Workplace Safety and Health Act (Chapter 354A), please click HERE.

4. Workplace Safety and Health (Risk Management) Regulations, please click HERE.

5. WSH Guidelines on Management of Hazardous Chemicals Programme, please click HERE.

6. School science laboratory safety regulations : for all primary and secondary schools, junior colleges and centralised institutes in Singapore / Science Unit, Curriculum Planning and Development Division, Ministry of Education.

Courtesy from WSH Council. For more info, pleas visit http://www.wshc.sg

Worker Fell When Boarding a Barge and Drowned

26 Sep 2012

At the start of a new workday at 7:40 am, the Deceased was transferring from a workboat (used to ferry workers) to a fixed vertical ladder for boarding a crane barge anchored at sea. While he was trying to climb up the ladder, he lost his balance and fell into the sea. The life jacket the Deceased was wearing immediately inflated and he successfully grabbed onto a life buoy thrown to him by the barge supervisor. However, the Deceased became unconscious before he could be rescued and was subsequently pronounced dead when he arrived at the hospital. An autopsy revealed the cause of death to be drowning.

Figure 1: Worker was attempting to board the barge                                       when he fell into the sea.

 

Recommendations*

Industry stakeholders undertaking similar work activities are advised to consider the following to prevent a recurrence:

• Use a safer alternative access route to the barge (e.g. via land access instead of boat access) whenever on-site conditions allow.

• Develop a safe boat embarking and disembarking procedure. Boat passengers must be briefed on the procedure and advised not to attempt the transfer if sea conditions are unfavourable or if the boat is rocking excessively.

• Confirm that passengers are physically and medically fit for work assignments involving sea travel. The rocking of the boat may cause some to have motion sickness. Passengers who are feeling unwell should not attempt to board the barge.

• Workboat operator to ensure that the boat is steady and kept as close as possible to the barge before allowing passengers to disembark. Ideally, a workboat attendant should be stationed to guide the passengers and assist in the vessel-to-vessel transfer.

• Adorn each passenger with a life jacket or flotation vest adequate for the body weight of the wearer

• Check that all passengers are wearing appropriate footwear (tight-fitting shoes or boots with non-slip soles) for the transfer. The gap between the ladder rung and the barge wall should be large enough for one to use the heel lift of the shoe or boot to “grip” the ladder rung.

Figure 2:  The boat should be kept as close as possible to the barge before passengers are allowed to climb onto the fixed vertical ladder.

• Advise passengers to maintain 3-point contact with the fixed vertical ladder at all times while climbing the ladder.

• Recognize and address the risk of passengers falling into the sea and put in place an emergency rescue plan.

Further Information

1. Workplace Safety and Health Act (Chapter 354A), please click HERE.

2. Workplace Safety and Health (Risk Management) Regulations, please click HERE.

3. Code of Practice on WSH Risk Management, please click HERE.

4. Guide to Safe Boarding of Vessels, please click HERE.

5. Singapore Standard SS 513: Personal Protective Equipment - Footwear

Courtesy from WSH Council. For more info, pleas visit http://www.wshc.sg

Managing the Dangers of Hot Work & Fall From Height

30 May 2012

Hot work poses serious explosion hazard and raises major concern on the safety of workers involved in such activity. The flames, sparks and heat produced during the hot work are ignition sources that can cause fires and explosions in many different situations.

A recent report released by the U.S. Chemical Safety Board (CSB) on a fatal welding explosion in a chemical facility highlighted the need to mitigate the risks from hot works. A welder was performing hot work on a tank which, unknown to him, contained flammable vinyl fluoride vapour at explosive concentrations. Ignition of the vapour resulted in an explosion that killed the welder and injured another.

Some learning points from this report include:

• Before and during any hot work, atmospheric and gas monitoring must be performed outside and inside the tanks to identify presence of any flammable vapours. For a very large tank, it is advised to carry out the gas monitoring in multiple locations (top, middle and bottom) to eure no residual flammables.
• All process pipings, including vent lines on tanks, are to be positively isolated before authorising any hot work.
• Rigorous hot work training and permitting procedures must be enforced.
• Whenever possible, avoid hot work and consider alternative non-spark producing methods.

Check out the CSB report HERE.

For more information on hotworks, please refer to the following links below:

Factsheet -  Do you know the dangers of hot work activities?

Case Studies -  Explosions

ProBE - Technical Advisory for Flammable Hazardous Substances

Occupational Safety and Health Circular - Safe Use of Oxygen-Fuel Gas Equipment

---

Worker Fell from Top Rung of Ladder

A worker was tasked to remove an existing ceiling lightings at the ground floor of a private apartment. The floor to ceiling height on the ground floor is 5m and the worker used a 2.8m aluminum A-frame ladder for his work. 

In the late afternoon, the employer, who was installing ceiling lighting at the 2^nd floor, heard a crash from the ground floor. He proceeded to the ground floor and found the A-frame ladder had toppled with the worker on the ground. The worker was found bleeding slightly from his mouth but was conscious.

He succumbed to his injuries later that same day in the hospital. According to the Employer, the victim was standing at the upper rung of the A-frame ladder to dismantle the ceiling lightings.

 

Recommendations*

Occupiers and employers undertaking similar work activities are advised to prevent recurrence by conducting risk assessment and applying suitable control measures prior to work commencement. Examples of control measures include:

• Use the right ladder for the job. For example, the ladder must be high enough for you to reach your work area without having to stand on its top rung. Standing on the top rung of a ladder is highly unsafe and it should never be done (See figure 1).
• As ladder has little or no fall prevention mechanism, the use of other safer equipment like scissor lifts or tower scaffold to reach higher work area may be recommended.
• Provide sufficient supervision to ensure on-site adherence to work safely

Figure 1: If it is necessary to work on a ladder, work a few steps below the top rung,

so that a handhold can be maintained.

For more information on working safely at height, please refer to the following links below:

Workplace Safety and Health Act (Chapter 354A), click HERE.
Workplace Safety and Health (Risk Management) Regulations, click HERE.
Code of Practice on WSH Risk Management, click HERE.
Code of Practice for Working Safely at Height, click HERE.
WSH Council’s Ladder Safety Kit, click HERE.

Courtesy from WSH Council. For more info, please visit http://www.wshc.sg

Changes to the Work Injury Compensation Act to take effect on 1 June 2012

21 May 2012

The amendments to the Work Injury Compensation Act (WICA) will take effect on 1 June 2012. Employers are reminded to take note of the changes to their liabilities as an employer and to ensure that they maintain adequate insurance coverage for their workforce.

Updating the   compensation limits	Limits have been increased to account for increase in nominal   wages and healthcare costs.
Disallowing   compensation for   work-related fights	While work disputes may arise from time to time, employees   should not resort to fights to resolve them, and employers   should not have to bear the cost of such injuries.     Exceptions will be allowed such as when exercising private   defence, instructed to break up fight, safeguard life/property or   maintain law and order.
Expanding scope of   compensable   diseases	Disease due to work exposure to chemical or biological agent   will be compensable.     Second Schedule for Occupational Diseases have been   refined to include “Disease caused by excessive heat”, remove   “SARS” and “Avian Influenza”.
Disallowing work-   related exclusion   clause in WIC   insurance policies	Insurers will be required to make compensation payment even   if there are work-related exclusions. Insurers will be able to   seek contractually from employer.
Clarifying liability of   employer’s insurer	When there are multiple insurance policies, employer’s   insurance will be the default policy used to satisfy a claim.
Clarifying obligations     under WICA and   common law	Claimants who filed a common law claim but subsequently   wish to file a claim under WICA have to do so within one year of   accident. Beyond this one year timeframe, the claim will not be   admitted under WICA.

 

Courtesy from WSH Council. For more info, please visit http://www.wshc.sg

Worker Died After Falling Through Viewing Platform on Board Ship

4 Apr 2012

Recently, a worker was killed when he fell from a viewing platform on board a ship undergoing repair work. At the time of accident, he was tasked to oversee the movement of the ship from the dock. When he was walking on the viewing platform that was made of metal gratings, a section of the gratings gave way. He fell through the opening and landed on the deck about 7.8m below.

Preliminary investigation revealed that the bracket supporting the grating was corroded and gave way under his weight  causing him to fall.
  

Schematic view of the scene of the accident

Recommendations*:

Industry stakeholders undertaking similar work activities are advised to consider the following to prevent a recurrence:

1. Conduct proper checks on all sections of the ship where workers are required to work safely;
 

2. Ensure safety inspections are carried out on the ship’s access and work platforms, railings, ladders and walkways, etc to ensure there are no corrosion or rusted parts before any work activities are allowed to be carried out;
 

3. Repair or replace corroded parts of the access and work platforms, railings, ladders and walkways, etc before allowing workers to access these areas;
 

4. Cordon off all unsafe work areas and put up “Danger - No Entry” signs;
 

5. Put up suitable safety signages at the work location to remind workers of the job hazards;
 

6. Supervise all work activities to ensure safe work practices are adhered to onsite.

For more information on Workplace Safety and Health, please refer to the following links below:

• Workplace Safety and Health Act (Chapter 354A), please click HERE
• Workplace Safety and Health (Risk Management) Regulations, please click HERE
• Code of Practice on WSH Risk Management, please click HERE 

Courtesy from WSH Council. For more info, please visit http://www.wshc.sg

Chef Killed in Oven Explosion

22 Mar 2012

Recently, a gas convection oven exploded in a restaurant when a chef attempted to turn it on. The impact of the explosion resulted in the death of the chef.

 

 

            

Recommendations*:

 

Stakeholders involved in similar work environment should undertake control measures such as the following to prevent recurrence:

 

1. Prior to the start of any work, conduct an adequate risk assessment to identify all hazards and the risks involved. Suitable control measures must be established and followed. For example, before the operation of the oven, if there is smell of gas leak, the gas supply must be turned off immediately. Any ignition sources in the vicinity must be isolated and the area ventilated.

 

2. Follow manufacturer’s instructions for oven use.

 

3. A licensed gas service worker (LGSW) must be engaged for any installation or alteration of gas pipes. Similarly, a qualified and competent technician must be engaged for any repair or maintenance work on the oven.

 

4. Conduct periodic inspection of the gas installation, for example, in looking out for frayed hose, loose connectors or defective valves. Engage competent person to correct any defects found.

 

All restaurant and kitchen crew must be adequately trained to be competent in their respective jobs, and be aware of the risks involved and safety precautions required.

For more information on Workplace Safety and Health, please refer to the following links below:

• Workplace Safety and Health Act (Chapter 354A), please click HERE  
• Workplace Safety and Health (General Provisions) Regulations, please click HERE 
• Workplace Safety and Health (Risk Management) Regulations, please click HERE 
• NFPA 86: Standard for Ovens and Furnaces
• Safe Use of Gas Ovens in the Food Manufacturing and Catering Industry, please click HERE 
• A list of the LGSWs is available at the Energy Market Authority (EMA)’s website at www.ema.gov.sg

Courtesy from WSH Council. For more info, please visit http://www.wshc.sg

WSH Alert – Worker Fell from Platform at Concrete Batching Plant

21 Dec 2011

 

A worker was tasked to hack and remove hardened concrete within the discharge hopper of a concrete mixing equipment. The equipment was located about 7 metres above ground with a work platform surrounding it. At about 12.20p.m., he was found dead on the ground directly below an uncovered opening on the platform. The metal grating for the platform’s opening was found removed.

 

 

 Figure 1: The concrete discharge hopper which the worker was working on

 

Recommendations*

 

Occupiers and employers undertaking similar work activities are advised to prevent recurrence by conducting risk assessment and applying suitable control measures prior to work commencement. Examples of control measures include:

 

• Replacing all easily removable platform floor gratings with permanently fixed ones to prevent unauthorized removal and eliminate possibility of workers falling from height through floor openings
• Documenting and communicating the safe work method for removal and disposal of hardened concrete  within the hopper – this include implementing a  Lock Out Tag Out (LOTO) system for the automated gate to ensure that the hopper discharge nozzle remains locked while the worker is carrying out hacking activity inside the hopper
• Providing sufficient supervision to ensure on-site adherence to the safe work method
• Barricading the zone directly below the hopper to prohibit access and protect workers and visitors from being struck by falling debris while hacking activity is being carried out in the hopper
• Posting suitable safety signages at the work location to remind workers of the job hazards

 

Further Information

 

1. Workplace Safety and Health Act (Chapter 354A), please click here
2. Workplace Safety and Health (Risk Management) Regulations, please click here
3. Code of Practice on WSH Risk Management, please click here
4. Code of Practice for Working Safely at Height, please click here
5. WSH Council’s Work at Height Kit, please click here
6. CP 91: 2001 Code of Practice for Lockout Procedure
7. Singapore Standard SS 508: Parts 1 to 4: 2004 - Graphical Symbols - Safety Colours and Safety Signs
8. Singapore Standard SS 528: Parts 1 to 6: 2006 - Personal Fall Arrest Systems

 

* Please note that the information provided is not exhaustive and is for the benefit of enhancing workplace safety and health so that a recurrence may be prevented. The information provided is not to be construed as implying any liability to any party nor should it be taken to encapsulate all the responsibilities and obligations of the reader of this WSH Alert under the law. 

---

WSH Alert – Workers Fell together with a Cherry Picker Basket

 

Incident

 

Two workers fell to their death while they were on a mobile elevating work platform (MEWP) to carry out abrasive blasting work on a vessel. They were in the basket of the MEWP (a cherry picker) about 25m from the ground, when the MEWP’s extended boom suddenly buckled. The basket, together with the two workers, dropped towards the ground and hit a keel block on the ground.

  

Figure 1: Workers fell together with the basket of a MEWP when the boom buckled 

Recommendations*

 

Occupiers, employers and workers undertaking similar work using MEWPs are advised to conduct hazard identification, risk assessment and implement appropriate control measures prior to work commencement. Examples of control measures include:

• Ensuring the MEWP is properly inspected and regularly maintained by a competent person in accordance with the manufacturer’s requirements. Inspection and maintenance records should be kept up to date.
• Establishing and communicating safe work procedures to the operators.
• Providing supervision to ensure on-site adherence to safe work procedures.
• Ensuring operators are properly trained and are familiar with the performance and control of the MEWP.
• Conducting daily pre-operation inspection and functional checks of all controls on the MEWP before use.
• Ensuring the operating weight is within the safe working load limit.

Further Information

 

1. Workplace Safety and Health Act (Chapter 354A), please click here
2. Workplace Safety and Health (Risk Management) Regulations, please click here
3. Code of Practice on WSH Risk Management, please click here

4. Code of Practice for Working Safely at Height, please click here

5. WSH Council’s Work at Height Kit, please click here

6. Britain’s Health and Safety Executive Information sheet – Preventing falls from boom-type mobile elevating work platforms, please click here

 

Courtesy from WSH Council. For more information, please visit http:www.wshc.sg