Mould at work
Mould at the workplace can be a serious health and safety hazard that could be putting your workers at risk.
Mould (also called fungi or mildew) is an organism that belongs to the fungi kingdom. To replicate, mould produces tiny particles called spores. These spores, similar to the seeds of a plant, only much smaller, are carried in the air until they settle on both indoor and outdoor surfaces. If the spores land on a moist surface under the right conditions such as with suitable water, food, temperature and oxygen the mould begins to grow.
Mould grows on various surfaces such as wood, paint, walls, wallpaper, fabric, ceilings, bathroom tiles, carpets, insulation material, around windows and pipes. Mould absorbs substances (organic material) from these surfaces eventually destroying them in the process. Left unchecked mould erodes building materials, furnishings and can cause structural damage to buildings.
What are the hazards?
Mould is present in both indoor and outdoor environments as part of the natural environment. When allowed to grow uncontrolled the presence of mould can be a potentially serious health hazard at workplaces.
People will react to mould exposure differently, depending on factors such as the amount of mould an individual is exposed to, the species of mould present and a person’s own level of health and sensitivity.
If mould is present at the workplace, it requires immediate attention and action regardless of the severity of any reaction’s workers may be experiencing.
Understanding the potential dangers and taking adequate precautions can significantly reduce the effects mould at the workplace can have on the health and safety of your workers.
How does mould get into the human body?
Mould spores and their toxins (mycotoxins) enter the human body mainly through three different routes.
- breathing (inhalation). Moulds enter the body through the respiratory system, sinuses and lungs.
- ingestion (eating or swallowing). Mould can land in our mouth and is swallowed, or it can be present on food that we eat that has been prepared or on food such as fruit or bread that may be sitting on the counter.
- skin (dermal absorption). Mould enters the body through skin contact by being absorbed through the skin or through a cut or a scrape on the skin.
What are the harms?
Moulds which are harmful to humans at the workplace can be categorised broadly into three different groups; Allergenic, Pathogenic and Toxigenic.
Allergenic moulds affect people who have certain allergies.
People exposed to these moulds who suffer from allergies may experience a hypersensitive reaction to them, resulting in an acute inflammatory response from the body’s respiratory system such as allergic rhinitis (a condition where the inside of the nose becomes inflamed by allergens).
Signs and symptoms of allergic rhinitis include sneezing, runny or stuffy nose, cough and postnasal drip, itchiness (eyes, nose and throat) and watery eyes.
Reactions to allergenic moulds range from mild to severe and may include any of the following: congestion, rash, itchy or watery eyes, difficulty breathing, swelling, difficulty swallowing, abdominal pain, cramps, vomiting, diarrhoea, dizziness and mental confusion.
These types of moulds may also trigger asthma if the mould spores are able to reach the lungs of people who suffer from asthma.
Most people without allergies are unaffected by allergenic moulds in environmental or small amounts.
Pathogenic moulds can cause certain infections or diseases.
These moulds mostly cause health problems to people with compromised or weakened immune systems (such as infants, elderly, cancer patients, transplant patients etc).
People who are fit and healthy with good immune systems are generally able to regularly fight pathogens, leading to less infection or disease from pathogenic moulds.
Pathogenic mould-related illnesses, classed as mycoses (fungal infections), result from a fungus that actually grows on or in human tissues or organs.
Pathogenic moulds may cause superficial, subcutaneous or systemic reactions in affected people.
Superficial reactions are the most common and may include skin infections, nail infections, ringworm, candida infection, or athlete’s foot, where subcutaneous (located or applied under the skin) reactions occur when an infection develops underneath the skin such as mycetoma or chromoblastomycosis.
Systemic reactions occur when the moulds attack the kidneys, liver or other organs and can be life-threatening.
Toxic moulds produce toxins (mycotoxins) which are poisonous chemicals that are dangerous to humans causing serious health problems.
Toxic moulds are a serious problem and any person exposed to these types of moulds may become ill.
Reactions to toxigenic moulds range from mild to severe and may include any of the following: skin rash, temporary irritation, eye infections, fever, nausea, fatigue, lung infections, suppressed or weakened immune system, acute or chronic liver damage, acute or chronic central nervous system disorders, neurological disorders, hormone disorders and cancer.
Who's at greatest risk of health problems from contact with mould?
People who are in a general state of good health and don’t have a history of respiratory or immunological conditions are unlikely to be affected by mould growth.
People with asthma, allergies or other breathing conditions may be more sensitive to mould.
People with weakened immune systems or chronic lung diseases are more at risk of mould infection, particularly in their lungs.
People who are at an increased risk of health problems from mould exposure should avoid mould affected areas and consult their doctor if they are concerned about mould exposure.
Workers who are sensitive to mould exposure should avoid mould affected areas at their workplace and notify the Person Conducting a Business or Undertaking (PCBU) as soon as practicable to enable the appropriate action to be taken to mitigate the risk of mould exposure to workers, visitors and others at the workplace.
Preventing mould growth
The key to preventing mould growth at the workplace is to prevent unwanted water entering a building, limit the amount of water vapour released inside the building, reduce dampness and remove excess moisture.
It is vital that good ventilation is maintained to prevent stagnant dead-air spaces or excessive humidity.
- keep mould-susceptible building materials dry during construction
- provide adequate drainage around buildings
- inspect and maintain the building and its fixtures regularly
- undertake repairs promptly to prevent water damage
- maintain heating, ventilation and air conditioning systems and make sure these are set to the environmental conditions
- manage water vapour and condensation, especially in high water vapour areas such as bathrooms and showers, i.e. provide ventilation and the ability to hang up towels or damp clothing
- clean up wet areas and water damage promptly (within 24-48 hours)
- check plumbing for leaks
- keep furnishings dry
- ensure good ventilation throughout the workplace
- have air handling systems maintained to manufacturers requirements
- look for areas of dead-air (no air movement) and excessive humidity during workplace inspections
- consider talking to your air handling provider about compliance with the AS1668 series of Australian Standards (Standards Australia)
Finding mould growth
Investigating mould can be difficult and in some circumstances is best left to an experienced professional with specialised equipment.
Mould investigation requires caution since disturbing mouldy areas may spread mould further throughout the building.
Personal protective equipment (PPE) should be available during any mould investigation and used when significant mould growth is identified.
Suitable PPE may include disposable overalls, a properly fitted disposable P2 mask / respirator, gloves and safety glasses.
Where there is a strong smell of mould, a properly fitted disposable P2 respirator with a carbon activated filter layer should be considered. In addition to minimising inhalation of mould spores, these masks will minimise exposure to the volatile organic compounds (VOC’s) sometimes produced by large areas of mould growth.
Mould investigations may be required in the following circumstances:
- when musty smells or earthy odours are reported
- where visible mould growth is observed (i.e. black spots on walls)
- where discolouration on walls, floors or ceilings have occurred
- where flooding or water leaks have occurred (i.e. water stains on walls)
- a condensation problem has been identified (i.e. on windows, walls or pipes).
Where mould is identified in a building, the size and extent of the mould damage should be determined, along with the source of the water or moisture problems that allowed the mould to grow.
If there is no obvious air movement, identify the nature of the local ventilation and ensure it is operating correctly.
In circumstances where the source of the mould growth is unclear, and people may be at risk of health problems specialist advice may be required to conduct sampling and laboratory testing. This testing should always be carried out by a competent person with appropriate equipment and using the correct PPE.
It's important to ensure that, when investigating any mould growth issues at the workplace, people take appropriate control measures regarding other health and safety issues that may be present such as:
- sewage contaminated floodwater
- hazardous chemicals
- confined spaces
- electrical hazards and pests such as rodents.
Cleaning mould contamination
Once mould contamination has been identified, fixing the underlying water, excess moisture or ventilation problem facilitating the mould growth is essential, otherwise the mould problem will return.
Cleaning mould affected areas may involve:
- restricting access to the affected areas and where possible scheduling work when the area or building isn't being used.
- closing doors and sealing air vents where possible to prevent the spread of mould spores.
- wearing appropriate personal protective equipment.
- ensuring people don't eat, drink or smoke in work areas.
- ensuring unprotected people leave the area during the cleanup operation.
- drying out the wet area as soon as possible if there's been a water leak or flood. Fans, wet vacuums, dehumidification units, heaters or air conditioners on dry mode can be used to speed up the drying process
- thoroughly cleaning contaminated hard surfaces and materials using water and detergent (soapy water) or a vinegar solution and drying completely. Cleaning all tools and equipment after use.
- discarding porous materials (ceiling tiles, plasterboard, insulation and carpets) that can’t be readily cleaned, have been wet for more than 48 hours or have visible mould growth. Seek professional assistance about restoring damaged items that are valuable or irreplaceable from an appropriately qualified competent person.
- wrapping and sealing contaminated items and discarding into plastic bags or sheets to reduce the spread of mould spores. These items can usually be discarded as general rubbish. We recommend seeking further clarification prior to disposal with the appropriate authority (e.g. local council).
- doing a final clean up to remove any dust that may have settled within the area or nearby.
Communication with building owners, occupants and tenants about mould issues and remediation work may be necessary during mould clean up operations to ensure they are aware of the work being undertaken, including when access to the affected areas can be granted following the clean up.
During the mould clean up, it's important to protect people from dust generated during the process as mould spores attach themselves to airborne dust particles.
If the dust isn’t properly captured, contained or suppressed it can spread to other workplace areas.
Control measures to stop the spread of dust during the cleanup will depend on the extent of mould contamination and disturbance and may include:
- Isolating affected area/s by:
- shutting doors and windows that lead to other areas of the building
- sealing supply and return air vents in the affected area to prevent dust entering these systems and being transferred to other parts of the building
- shutting down the heating, ventilation or air conditioning (HVAC) systems servicing the area
- using floor to ceiling plastic sheeting with sealed edges (dispose of appropriately).
- Preventing dust becoming airborne by:
- using cleaning methods that minimise dust, such as spraying contaminated material with a mist of water before disturbance
- using a vacuum with appropriate filtration system
- dry sweeping, household vacuums and compressed air generate large amounts of dust and should be avoided.
Completing the mould clean up
There may be different opinions regarding when the mould cleanup is finished.
If it's unclear if the cleanup has been effective it may be necessary to seek professional advice such as a competent person with the appropriate qualifications to make this determination.
Other general indications the mould cleanup has been completed may include:
- the water leak or moisture problem has been fixed
- there is no visible mould, mould-damaged materials or mouldy odours at the site
- an inspection of the area following the cleanup confirms there has been no new water damage or mould regrowth.
Personal hygiene practices
Workers who work with mould should be provided training in personal hygiene practices to ensure they are not adversely exposing themselves to health and safety risks of mould contamination, in particular through ingestion or inhalation.
Workers should wash their hands thoroughly with soap and running water in the following circumstances:
- before eating, drinking or smoking.
- after contact with mould
- after removing PPE.
Workers must be provided with hand washing facilities. This includes clean running water and non-irritating soap, preferably from a soap dispenser. Hygienic hand drying facilities must also be provided, such as automatic air dryers or paper towels.
Due to the nature of potential mould contamination to workers it is preferable to supply field workers with portable hand washing facilities.
If work is carried out in locations where there are no hand washing facilities, workers should have access to alternative hand hygiene facilities, for example a water container with soap and paper towel.
Information and training
Workers should be provided with adequate information about the health risks of mould contamination at the workplace.
This may include ensuring workers are trained:
- to recognise mould contamination on surfaces to minimise health and safety risks at the workplace
- in safe work procedures to identify and control mould contamination at the workplace
- in the proper selection and use of PPE to protect themselves from health and safety risks of mould exposure.
Personal Protective Equipment (PPE)
Workers must be provided adequate PPE to protect themselves against mould exposure and to prevent the spread of mould to other areas of the workplace.
The purpose of PPE is to prevent the inhalation and ingestion of mould spores and to avoid mould contact with the skin or eyes.
Skin and eye protection
Gloves protect the skin from contact with mould while also protecting the skin from chemical cleaning solutions.
Gloves should be selected based on the type of cleaning chemical used and according to the information contained in the safety data sheet (SDS) or provided on the container of the chemical.
Properly fitted safety goggles designed to prevent the entry of dust and small particles should be used to protect the eyes during mould remediation work.
Respiratory protection is essential during mould remediation processes to protect workers from inhaling airborne mould, contaminated dust and any other particles that may be released.
Respiratory protection such as a properly fitted disposable P2 respirator, P2 with carbon activated filter layer or full face respirators are recommended for use in mould remediation, depending on the extent of mould growth and the duration of the task.
All face masks or respirators used must be properly fitted and comply with the relevant Australian Standard to ensure they have been certified for use in Australia.
Workers who use face masks or respirators must be adequately trained and be properly fit tested (where applicable) before using them.
The face mask or respirator must have a tight seal around the face so most of the air inhaled goes through the face mask or respirator to protect the wearer.
The workplace must also have procedures for the safe removal, disposal (for non-reusable face masks/respirators) and storage of respirators to ensure they do not become contaminated when not being used.
Reusable or disposable personal protective clothing is recommended to reduce cross-contamination from work areas to clean areas, to prevent the transfer and spread of mould onto street clothing and to minimise skin contact with mould.
Protective clothing may include aprons (impervious), overalls (impervious) and shoe and boot covers.
All single-use or disposable PPE must be discarded after use. Used PPE should be placed into an impermeable bag to prevent any contaminants spreading to other work areas and be disposed of appropriately.
Other hazards to consider include:
- Managing risks of hazardous chemicals in the workplace - COP – mould remediation work can involve the use of hazardous chemicals, which can be dangerous for people handling and applying them. Some mould cleaners are highly corrosive and the fumes from these powerful cleaners, particularly in enclosed spaces, present a significant health and safety risk to people. Always follow the directions on the Safety Data Sheets (Safety Data Sheets for Hazardous Chemicals – COP) when using hazardous chemicals.
- Electrical and power/electrical work – the risk of injury from electricity is strongly linked to where and how it is used. The risks are greater in harsher conditions such as in indoor or outdoor environments in potentially damp or wet surroundings where electrical equipment may become wet and damaged. Always use electrical equipment that is safe to use (inspected and tested by a competent person) and appropriate for the conditions.
- Slips, trips and falls on the same level – the risk of slip, trip or fall injuries working in potentially cramped or dark locations when conducting mould investigations or mould remediation work is a serious health and safety risk. These types of injuries can occur in any workplace at any time and can result in sprains, strains, soft tissue, back or permanent long-term injuries. Always consider the potential for slip, trips and falls hazards in work areas and take action to mitigate any risks identified.
- Remote and isolated work - Working alone or remotely increases the risk of any job. Exposure to violence and poor access to emergency assistance are the main hazards that increase the risk of remote or isolated work. Mould remediation workers working remotely or in isolation can be exposed to health and safety hazards from mould and hazardous chemicals in enclosed rooms, electrical risks, confined spaces or pests and rodents. Always ensure remote and isolated workers are; aware of the health and safety risks, monitored, provided with an effective means of communication and there is an effective emergency response plan in place if required.
Technical help and resources
Codes of Practice and Guidance
For more information about the risk management process see Code of Practice for How to manage work health and safety risks
For more information about the workplace facilities see Code of Practice for Managing the work environment and facilities
SafeWork NSW Guidance and Resources
NSW Health Mould factsheet
Last modified: September 2020