Part One of this series of articles examined the types of chemicals handled and stored in laboratories, and how to identify these substances and the health and physical hazards they present
Part Two provides guidance on how to manage and control the risks associated with storing and handling these chemicals.
How to Comply With the WHS Act and WHS Regulations
As with other Australian workplaces, laboratories and the people working within them have specific duties under the model WHS Regulations to manage the risks to health and safety associated with using, handling, generating and storing hazardous chemicals at a workplace.
These duties include:
- Ensuring that all containers (and pipework) are labelled correctly with appropriate warning placards and safety signage
- Maintaining a register and manifest (if manifest quantities are involved) of hazardous chemicals used or stored in or outside the laboratory
- Notifying the regulator if manifest quantities of hazardous chemicals are stored on site
- Identifying the potential risks of chemical or physical reactions of hazardous chemicals and ensuring these chemicals remain stable
- Ensuring lab technicians and other workers are not exposed to hazardous chemicals in a manner that exceeds workplace exposure standards
- Ensuring lab staff have access to health monitoring facilities if required
- Providing lab staff with adequate information, training, instruction and supervision
- Putting in place suitable spill containment systems for any hazardous chemicals used in the lab or storage area
- Ensuring the relevant Safety Data Sheet (SDS) is securely stored and easily accessible
- Maintaining control of ignition sources as well as the accumulation of flammable and combustible substances
- Ensuring the provision of fire protection and firefighting equipment, and emergency and safety equipment
Important documents including Safety Data Sheets (SDS) can be stored safely in secure document holders
How to Follow the Model Code of Practice: Managing Risks of Hazardous Chemicals in the Workplac
The model Code of Practice: Managing risks of hazardous chemicals in the workplace provides guidance on how to manage the specific risks associated with hazardous chemicals in the workplace.
The Code advocates using the following systematic methodology:
- Identify any potential hazards - focus on what could harm people, property or the environment.
- Assess the risks - unless dealing with known risks with known controls, you must work out what type of harm the hazardous chemicals could cause, as well how serious the harm could be and the likelihood of it occurring.
- Eliminate the risks - as much as it is reasonably practicable to do so given the chemicals involved.
- Control the risks - if eliminating the risk is not reasonably practicable, implement the most effective control measures (that are reasonably practicable in the circumstances) according to the hierarchy of control measures, and ensure they remain effective.
- Sustain - review the control measures regularly to ensure they are still working
Australian Standard for Safety in Laboratories - Storage of Chemicals
Another authoritative source of information specific to ensuring safety in laboratories is a series of standards - AS/NZS 2243 - Safety in laboratories - published by Standards Australia that focus on promoting safe working practices in laboratories.
Part 10 of the AS/NZS 2243 series (AS/NZS 2243.10:2004 - Safety in laboratories - Storage of chemicals) is dedicated to the appropriate storage of chemicals and dangerous goods both within laboratories and within dedicated storage areas that are support areas for a laboratory.
The Standard covers the basic principles of storing chemicals to ensure the safety of people, property and the environment both inside and outside the laboratory.
Dangerous goods from Class 1 (Explosives), Class 6.2 (Infectious substances), and Class 7 (Radioactive substances) are not covered by this Standard but are covered in other parts of the AS/NZS 2243 series.
Storage of chemicals outside the laboratory entails a choice of risk control measures dependent on the class or mixed classes of dangerous goods involved. The choices include the undertaking of a risk assessment to determine which control measure should be applied for that particular chemical storage scenario.
An expert chemical risk assessment and compliance audit can help prevent costly workplace accidents
What is the Hierarchy of Control Measures?
The hierarchy of control is a method of ranking the control measures that can be implemented to control the risks associated with hazardous chemicals
According to the model Code of Practice: Managing risks of hazardous chemicals in the workplace, the first priority is to eliminate a hazard and any associated risks.
If eliminating the risk is not feasible, it must be minimised by using one or more of the following three approaches:
3. Engineering controls
If these approaches fail to adequately minimise the risk associated with the hazardous chemical, administrative controls must also be implemented, along with suitable personal protective equipment (PPE).
Administrative controls are about changing the way people work inside and outside the laboratory through supervision and training, as opposed to controlling the hazard at its source.
Eliminating Chemical Hazards in a Laboratory
Although the most effective risk control measure and the first one to be considered, the elimination of a chemical hazard (and the associated risks of using that hazardous chemical) is often not a practical solution in the laboratory context.
Elimination controls, or removing the hazard or hazardous work practice entirely from the lab, may simply be impractical when the chemical and the activity involved are intrinsic to the laboratory’s operations.
However, occasionally there will be an opportunity to eliminate the presence of a dangerous chemical by using premixed chemicals or by sending substances to an offsite facility for further testing and observation.
Even then, however, the danger remains that another unforeseen hazard emerges as a consequence of modifying the process. Consider the following laboratory scenario where elimination controls are implemented:
|Task||Hazard||Elimination Controls||Potential New Hazards|
|Lab tests require Chemical C which involves the mixing of two volatile substances - Substances A and B||Mixing the substances by hand creates a dangerous chemical exposure hazard||
Option 1: Use premixed chemical to eliminate the need for mixing onsite
Option 2: Send the volatile substances to an offsite testing facility to completely remove Chemical C and its compounds
People are still handling hazardous chemicals at some point
Insufficient quantities of premixed chemical leads to people reverting to mixing substances onsite
Substitution of Hazardous Chemicals in the Laboratory
Similarly, the substitution of a hazardous chemical with another chemical that is less hazardous may not be practical in the context of the laboratory’s work practices.
Some hazardous chemicals are used in lab-based activities for their very specific properties, such as their evaporative abilities, and substitute chemicals are not viable alternatives.
For example, a chemical such as pentane - C5H12 - which evaporates very rapidly, is extremely volatile. The more volatile a substance is, the lower its flashpoint and the more easily it will ignite in the presence of an ignition source.
However, if the opportunity presents itself to substitute a hazardous chemical with a less hazardous chemical without compromising the task at hand, then substitution is the recommended control measure. For example, using acetone - (CH3)2CO - which has a flashpoint of -18℃, as a substitute for pentane, which has a lower flashpoint of -40℃.
Example scenarios of hazardous chemical substitution in the lab to control risk could include:
- Using a less volatile chemical to control the risk of a vapour hazard
- Substituting a highly flammable liquid with one that is less flammable or combustible
- Choosing hazardous chemicals designated with a single hazard class rather than chemicals with multiple hazard classes
- Substituting high hazard chemicals such as carcinogens, mutagens, reproductive toxicants and sensitisers with less hazardous substances
- Using diluted acids and alkalis rather than their concentrated forms
While substitution is about finding safer ways of doing the same task in a laboratory, elimination is about removing that task altogether. Whichever outcome is achieved - elimination or substitution - a proper risk assessment should be conducted to determine any new hazards.
Isolation and Segregation of Hazardous Chemicals in the Laboratory
Isolating hazardous chemicals from people and other chemicals (or things) that are incompatible is mandatory.
Isolation can be achieved using distance, barriers and appropriate chemical storage facilities.
Examples of isolating lab workers from hazards includes the use of fume hoods with exhaust extraction capabilities to remove dangerous airborne hazards from the work area or using closed or sealed systems for chemical dispensing and transfer.
Isolating hazardous chemicals from other chemicals - also called segregation of chemicals - is achieved by using distance, barriers or a combination of both.
Flammable liquids should be stored in secure, purpose-built safety cabinets that comply with AS1940
Engineering Controls in the Laboratory
If isolation of the hazardous chemicals is not possible or falls short of the required standards, there are engineering controls that should be implemented where possible
These controls are physical in nature and include devices or processes that eliminate or minimise exposure to the hazards. Use engineering controls to:
- Minimise the generation of hazardous chemicals
- Suppress or contain hazardous chemicals
- Minimise the impact of contamination in the event of a spill
Engineering controls include mechanical ventilation systems, compliant chemical storage containers or the automated processes involving hazardous chemicals.
Engineering Controls: Enclosed Storage
To meet the requirements for the Standards covering the storage and handling of chemicals in the laboratory, certain dangerous goods will need to be securely stored in compliant chemical storage cabinets.
Indoor chemical storage cabinets are designed to:
- Protect the contents of the cabinet against damage
- Ensure segregation between incompatible substances
- Contain spills
- Allow a minimum of 10 minutes for people to escape or access firefighting equipment in the event of fire
Some dangerous goods require cabinets made from chemically-resistant materials to prevent corrosion, adequate ventilation to prevent explosion or fire flashover, and spill trays to contain any spillages.
For example, harsh corrosive chemicals such as sulphuric acid can cause significant damage to metal surfaces, which is why laboratory-strength concentrations of this acid should be stored in cabinets constructed from high-density polyethylene and fitted with ventilation ports and high-capacity liquid-tight spill containment sumps to contain spills.
This brief video demonstrates the features of these metal-free polyethylene corrosive substance storage cabinets.
The location of chemical storage cabinets is also a key factor in minimising the risks these hazardous chemicals present. They must not be stored:
- Above or below each other
- Closer than 3 metres from any emergency escape routes
- Under stairwells or in corridors
- Within 3 metres of an ignition source
Where laboratory cupboards are used to store hazardous chemicals, their construction and the materials used must be compatible with the chemicals. Spill trays should also be in place as well as adequate ventilation where required.
Engineering Controls: Open Storage
Where hazardous chemicals are kept on shelves or racks in a laboratory, the following restrictions apply:
- For shelves over benches, the chemical must not be stored on shelves higher than 1.5 metres from the floor
- The shelving and fixtures must be compatible with the dangerous goods being stored, or be suitably protected from those goods
- The shelves’ maximum holding capacity must not be exceeded - To support effective housekeeping, chemical packages should not be stored on the floor
- Shelving used for storing chemical storage should not be subject to any lateral movement
- To reduce the risk of contamination, liquids should not be stored above solids - Liquids should be stored as low as possible to reduce the risk of breakage and spillage, with adequate bunding provided
Bunded shelving complies with WHS Regulations and removes the risk of large spills in the lab
Administrative Controls in the Laboratory
Because they don’t aim to control the hazard at the source, administrative controls are considered to be as effective as the higher order controls.
Administrative controls, can, however, be useful for helping to ensure the people who work in the laboratory are better equipped to handle an emergency situation such as a chemical spill or leak, or when other control measures fail.
Administrative controls can include documented policies and procedures outlining best work practices to minimise lab workers’ exposure to hazardous chemicals.
These policies and procedures aim to:
- Reduce the number of people exposed to hazardous chemicals - For example, a restricted area policy
- Reduce the duration and frequency of workers’ exposure to hazardous chemicals - For example, time limits for working with certain hazardous chemicals
- Reduce the quantity of hazardous chemicals kept in the lab - For example, a just-in-time ordering policy or preferential ordering of premixed chemicals
- Reduce the possibility of fire or explosion - For example, procedure to prevent introduction of ignition sources to the lab
- Reduce the impact of chemical spills or leaks - For example, spill clean-up procedure
A chemical spill kit is a vital component of a chemical spill response plan
PPE in the Laboratory
Laboratory workers are well-versed in the use of workplace PPE as a safety control measure, including lab coats, chemical resistant glasses, face shields, chemical resistant gloves and respiratory equipment.
Although PPE can greatly reduce the possibility of people being injured or harmed in the lab, PPE can never be relied on as the sole means of controlling a chemical hazard and is the least preferred option in the Hierarchy of Control Measures.
The effectiveness of PPE depends on its suitability for the task at hand, staff training and how well the PPE is maintained and stored.
PPE cabinets help keep PPE items clean and easily accessible
Hazardous chemical storage specialists STOREMASTA can help you with everything from dangerous goods storage solutions, a compliance audit and risk assessment, and even virtual dangerous goods training for your laboratory personnel.
STOREMASTA has also developed an eBook explaining how to implement the Hierarchy of Controls to control the risks associated with hazardous chemicals such as those used in the laboratory. This free eBook helps you select the most effective risk control measures and implement all the required mandatory controls in accordance with WHS Regulations.