Scope: Conservation Services Department Policy Regarding Moldy Collections

Contact: Beth Doyle

Unit: Conservation Services Dept.

Date last reviewed: 05/15/2025

Date of next review: 05/15/2026

Mold remediation requires significant time and resources to address and can be a health and safety risk to staff and patrons. Conservation Services is implementing this mold policy to reduce exposure to our staff and patrons, and to aid selectors and curators in decision-making when mold is identified or suspected.

Conservation Services can treat minor mold occurrences in-house, but remediation for more complicated or larger occurrences will be vended out. Conservation will review moldy materials on a case-by-case basis and discuss options with stakeholders. If Conservation Services decides not to treat moldy collection materials in-house, and the materials must be retained, we will work with stakeholders to find a suitable vendor(s) for remediation. If remediation is vended out, the department or division responsible for the collection will pay all associated remediation costs.

In general (see Decision-making Guidelines below):

• Small amounts of mold: Conservation will clean in-house.

• Medium amounts of mold: Conservation will review and recommend in-house or vendor.

• Large and X-Large amounts of mold: Remediation will be vended out.

1. Staff and patron safety is the primary goal. Access and use of collections remain a priority.

2. When mold is identified, a collection/content appraisal will be requested prior to any remediation work. The materials should be isolated until the appraisal is conducted. Materials should be appraised within 45 days.

3. Conservation Services has the right to refuse to work on moldy collections. That decision will be made at the discretion of the Conservation Services Department Head on a case-by-case basis and depends on staff resources and the extent of the outbreak.

4. Conservation Services will work with library staff to identify and remediate mold. Remediation may be done by Conservation Services if resources are available. If collections need to be vended out, we will help coordinate the work with stakeholders and vendor(s).

5. If newly-acquired materials require a vendor for mold remediation, the department or division responsible for the collection will be asked to fund packing, freight to and from DUL, remediation/treatment, and any other associated costs.

6. If materials are already in our stacks, those costs will be borne by Collections Services unless otherwise negotiated.

The following are guidelines Conservation will use to determine whether remediation will be done in-house, or if we will use a vendor.

Small mold remediation project—In-House

• Up to 50 sheets of paper (bound or unbound)

• Paper is sturdy and is not brittle or damaged

• No post-cleaning conservation/repair

• Mold is dry and inactive, very light coverage

• No drying/freezing/re-foldering needed

• Vacuum or sponge only

• Time: 2 hours or less

Medium mold remediation project—In-House or Vendor

• Up to 200 sheets of paper (bound or unbound)

• Paper in good to fair condition

• Minimal post-cleaning conservation/re-foldering

• Mold is dry and inactive, light coverage

• Some freezing and/or air drying needed to dry paper

• Vacuum

• Time: 2-20 hours

Large mold remediation project--Vendor

• 200+ sheets of paper (bound or unbound)

• Paper may be weak/damaged

• Post-cleaning conservation likely needed

• Mold is active, medium coverage

• Drying/freezing needed

• Vacuum

• Re-foldering/enclosures needed

• Time: 20-100+ hours

XL mold remediation project--Vendor

• Likely contracted out

• Large collection (bankers box+)

• Paper may be fragile or not

• Mold is active, heavy coverage

• Vacuum freeze drying, gamma radiation, or ozone treatment needed

• Conservation may be needed, may be extensive

• Extensive re-foldering/re-boxing

• Labor, supplies, equipment, shipping, insurance costs

• Time: several months

Exposure to mold can cause allergic reactions or respiratory symptoms even in people not prone to mold allergies. These reactions can be immediate or delayed. Individuals may develop severe mold allergies over time. Some allergies may become debilitating.

Personal Protective Equipment (PPE) should be worn when working with collections that are visibly moldy or suspected to be moldy. These include nitrile gloves, N95 mask or approved respirator, long sleeves and pants that are washable in hot water and detergent, and non-vented goggles. Mold identification and removal is best done in a fume hood or outside if the weather permits. After working with moldy collections, wash your hands thoroughly and place clothing immediately into the washing machine or into a sealed bag for washing later.

Mold spores are all around us every day. Spores can remain in their dormant state for extended periods of time and will reactivate when environmental conditions are suitable. Sustained humidity levels over 65% rH will support mold growth.¹

Mold can grow on all surfaces in the library including animal- and paper-based materials (books, manuscripts, photos, etc.), tables, shelving, carpeting, furniture, etc.

Collection materials can often be cleaned through freezing and vacuuming, and/or chemical treatment. Mold can permanently stain and weaken substrates making items difficult to use or copy. Moldy collections are also very susceptible to future outbreaks, even after cleaning. If previously treated collections are requested/circulated, proper PPE should be provided to users upon request.

Proper environmental conditions must be maintained after cleaning to prevent future outbreaks. Conservation Services monitors collection environments to identify and respond to issues quickly. We rely on library colleagues to bring moldy materials to our attention so we can address these before mold can spread and a larger outbreak occurs.

Mold can be inactive or active. Inactive mold is dry and powdery. Active mold has a three-dimensional quality and can look fuzzy or slimy. Mold can be a variety of colors and sizes.

Foxing, insect feces, water damage, and dirt can often look like mold. It is best to err on the side of caution and bring any suspected mold to Conservation Services’ attention.

Open

DUL and RL should carefully consider acquiring or retaining materials that are moldy. Please bring Conservation Services into the discussion as early as possible when mold is found in new acquisitions, preferably before items are sent to the library.

If you find mold in newly acquired collections, or if you are reviewing collections offsite for potential acquisition, please ask yourself the following questions:

• Are the materials damp or wet? Is there evidence of water damage?

• Does it smell “musty?”

• How extensive is the mold? A few pages, or is the entire box affected?

• Are there other moisture-related problems?

  • Are pages stuck together because of mold or moisture?

  • Is the media running due to being wet?

  • Are there rusty paperclips, pins, etc.?

  • Are there signs of insect or rodent infestation?

• Are these materials unique or are they duplicated in the collection either physically or electronically?

• How do you envision patrons accessing these materials?

• Can materials be copied/digitized and the originals discarded?

• Do you have funding for vendor-supplied freezing and cleaning? Digitization?

• Refer to the Ivy+ Hazards in Collections—Considerations for Discussion for further questions to ask yourself prior to accepting and accessioning hazardous materials, including mold. See Appendix A.

If you find mold in existing collections, please consider the following:

• Are the materials damp or wet? Do they show evidence of past moisture damage?

• How extensive is the problem? Are there other issues such as insect and rodent infestation?

• Are these materials unique or are they duplicated in the collection physically or electronically?

• Can these materials be replaced with similar copies? Can they be digitized and deaccessioned?

• Can these materials be discarded/deaccessioned?

Next steps:

• If you find mold, isolate the materials by placing them in a well-sealed bag, or seal the boxes with packing tape. Do not send to the stacks or LSC.

• Contact Conservation Services for a consult.

  • Conservation Lab 919-660-5906 o Department Head’s Office 919-660-5985

  • For mold found in non-collection areas: call FDS 919-660-5868

• Conservation Services may advise freezing on site or vending out freezing and cleaning prior to processing and shelving.

• Selectors/Curators should assess the moldy items within 45 days to determine if items can be deaccessioned or returned to the donor (sooner is better). The collections must be isolated or sealed shut during storage. Do not send moldy collections to the stacks or to LSC, even if sealed.

• If moldy materials have been newly acquired, the department who accepted the material will be asked to fund the remediation and/or digitization of the materials.

Collections emergency documentation for DUL staff https://duke.box.com/s/1x5ck51ildvcuzk5yw373rapj4a20iba

Harvard “Managing Mold Contamination”

https://preservation.library.harvard.edu/managing-mold-contamination

NEDCC “Emergency Salvage of Moldy Books and Paper”

https://www.nedcc.org/free-resources/preservation-leaflets/3.8-emergency-management/3.8emergency-salvage-of-moldy-books-and-paper

Goals: 1) Determine the scope of hazards present in our cultural heritage collections (libraries, museums, and archives) by collecting data and case studies from within our institutions. 2) In partnership with others to collaboratively compile this information and provide informed best practices for working with these materials.

Campus health and safety. Processing staff. Registrars. Collection managers. Curatorial staff.

¹ Some mold species recently found in cultural institutions may grow at humidity levels below 60%. See Bastholm, “When Mould is a Museum Visitor.”