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Prevent or treat mould

1. The problem with mould

Mould (including fungus and mildew) is a health hazard, particularly if you are handling contaminated material. It can render your records unusable and can be very expensive to treat and control.

It can form on any surface, but it particularly likes dirty surfaces, organic materials (e.g. paper, card, leather, parchment, and linen), glues and some chemicals found on videos, film, and CDs.

Some media will be unsalvageable once mould starts to grow–if any part of a video, film CD etc. is damaged, you might not be able to access it.

Mould indicates water damage or dampness, and potential problems with ongoing environmental controls and conditions. It also provides a food source for pests such as paper-lice and silverfish.

2. Prevent mould

Mould may be dormant or active depending on where it is in its life cycle.

Dormant mould spores are on all things at all times. They can easily be carried on air and transferred through contact.

There are 3 key things that mould needs to become active and grow:

  • spores
  • something to feed on
  • the right environmental conditions, particularly moisture.

Mould will become active in high levels of relative humidity or if the material has become wet or damp, particularly if left that way for any length of time.

It thrives in stagnant, poorly ventilated, dusty, dirty and oily, or greasy environments.  The rate of growth increases as the temperature rises.

Mould changes the material it grows and feeds on so that future infestations become easier. Once something has been mouldy, it will have high levels of residual spores just waiting to become active again.

Read about the appropriate conditions to store records.

3. Identify mould

Mould can be tricky to spot as it comes in every colour and may blend with the material it is infesting.

Dormant mould appears dry and powdery.

Active mould has a fluffy appearance; it may appear moist and slimy with a distinctive musty odour. It will smear when touched and the affected surface may appear pitted, or look eaten. Affected records may feel cool, damp or clammy to touch, and there may be a musty odour.

Some salts, surface dirt, stains and other phenomenon can give the appearance of mould. Refer to an expert if in double when identifying mould.

4. Treat mould

If you suspect you have mould growing (or waiting to grow) it is important to treat it quickly and thoroughly.

Note: Mouldy permanent records cannot be transferred to Queensland State Archives until they’ve been treated.

To deal with mould, follow these 5 steps.

  1. Apply health and safety controls.
  2. Confirm and evaluate.
  3. Isolate affected material.
  4. Treat (clean, dry and sterilise).
  5. Apply environmental controls.

These apply to anything that may be affected by mould.

For a large-scale outbreak, you may have to initiate your disaster response plan. Your agency or insurer may have approved vendors or contracts in place for remediation, salvage and cleaning.

Apply health and safety controls

Take care working in areas where mould is present—particularly when handling items affected by active mould or where you suspect that is the case.

You must wear personal protective equipment (PPE) including disposable gloves (nitrile is preferred), masks, eye protection, coats or aprons.

You should work on mouldy records in a well ventilated area and be conscious of your personal hygiene.

Confirm that it is mould and the extent of the problem

Undertake a thorough check to identify all potentially contaminated materials. Remember that there could be mould on anything, not just records.

Identify contaminated items that can be discarded (ensure that control information is not lost when throwing out file covers, boxes etc.)

Focus on the records and any other materials that must be retained.

Check the extent of affected areas (e.g. walls, ceiling, voids, carpets, and shelving).

If unsure, take and send clear photos to an expert, or have them come in and examine materials, take samples and confirm through tests.

Isolate affected material

Isolate and quarantine affected records to limit the spread of mould and for health and safety. Bag and label as ‘contaminated mould’. Keeping them cool will also help slow growth.

Relocate bagged items to a secure quarantine area for treatment. Do not allow access by staff or the public.

Clean, dry and sterilise affected materials

You will need to clean mould from the records and the facility before records are reintroduced.

Cleaning facilities

Ensure that the storage area is clean, dry and the environment is stabilised.

Ensure that only vacuum cleaners fitted with HEPA filters are used to remove spores, dust and dirt.

Hard surfaces (not records) can be wiped clean with alcohol-based wipes or industrial methylated spirits.

Chemicals, including bleach solutions, are not recommended, but can be used if necessary. If used, make sure that Safety Data Sheets are kept and that you rinse all treated surfaces. This will prevent chemical residue that may cause health and safety risks or interact with records later.

All surfaces must be fully dried.

Cleaning records

We recommend that a trained professional or reputable remediation company treat mouldy records.

Paper records and other organic materials are often difficult to clean, but, to prevent another outbreak, you must remove residual spores engrained in and on records.

Remove contaminated non-record materials and items. If they cannot be salvaged or cleaned, consider discarding them rather than using expensive treatments.

Sterilization using radiation, heat, fumigants, ozone (commonly used for odour reduction), ultraviolet light or other methods can pose a significant risk to records. You must carefully consider this using a risk-based approach and fully document your decisions.

To avoid ongoing health risks, residual spores and mould fragments will need to be cleaned from materials after sterilization treatment.

Rectify and monitor environmental conditions

Ensure that water leaks or other sources of moisture are investigated and rectified, and that all active mould within the facility has been found and treated.

If the source of the leak cannot be found and fixed, consider moving or protecting the records in situ, or relocating to better storage facilities.

Monitor the environment and ensure that relative humidity levels are kept below 60% and temperatures cool–this will help to prevent further outbreaks. Continue to monitor records that have been treated for mould.

5. More information