Talk:BPG Mold

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This discussion page was started by Katherine Kelly in June 2014 to collect ideas for improving this page, and to describe the process of editing it thus far. It includes the suggestions offered by the BPG Publications Committee, PCC Task Force in 2007-2009. If you are a registered user, please feel free to add your own suggestions for improvement.

Photos That Could Use a Home

White mold and darkly-pigmented (dematiaceous) mold. Photo by Ann Baldwin.
Artwork with mold. Image courtesy of The Fine Arts Conservancy.
Artwork with mold. Image courtesy of The Fine Arts Conservancy.

Overall Goals

  • to restart the process of editing the PCC. The mold/fungi page has not been edited for content since the pdf was converted to wiki format in May 2009.
  • to serve as a model for restarting the editing process on other PCC pages.

Recent Changes

In June 2014, the page was essentially the same in content and presentation as the 1994 print edition of the PCC. Since then, the process of editing has included:

Stylistic Changes

  • The formatting has been updated to remove references to this as Chapter 12 (and cross-references to “Chapter 12” elsewhere in the wiki have been updated), and to follow the Template for New BPG Chapter
  • In 2014-2017, the content was divided into multiple sub-pages. This was reversed in 2017 as it seemed confusing and did not match well with the overall structure of the wiki.--Kkelly (talk) 17:12, 6 July 2017 (CDT)
  • Content reorganized along a new outline (still preliminary and under review).
  • Some of the section headers were renamed. i.e. "Factors to Consider” became "What is Mold?"

Content Deletions

  • Removed some print PCC content:
    • how-to instructions for culturing mold
    • signatures from individual paragraphs (e.g. "(TP)")

New Content

  • Page name changed from “Mold/Fungi” to “BPG Mold” (Wikipedia defines mold as multicellular and fungi as the broader term including single celled yeasts).
  • Updated, annotated bibliography.
  • Several new sections have been added (without content as yet), including:
  • gamma radiation
  • case studies
  • biological safety cabinets

Suggestions for Improvement

Style and Format:

  • Standardize citation style to JAIC standards and link to online resources when possible.
  • A more detailed table of contents would help readers quickly grasp the scope of the entire chapter.
  • Several authors sometimes make essentially the same point in sequential paragraphs. These could be condensed.
  • Overall, the page could use more in the way of focus/direction. The section on "Purpose" could be improved to define the audience and purpose for this page.


Content Building:

  • Add links to online resources, both within the conservation wiki (Health and Safety, Disaster Response, PMG, textile, and objects mold pages) and elsewhere (CDC, EPA).
  • Add images, including photomicrographs of mold.
    • EPA has photos we are allowed to use here.--Kkelly (talk) 15:23, 1 July 2015 (CDT)
  • Search out terms like "now available", "contemporary", "recently", "soon", and "since the turn of the century" and update them. And, if I may quote the 1994 page itself, "Any recommendations in the literature that are more than a few years old should be viewed with skepticism, since it is only in the last few years that the toxicity of a wide range of biocides has become a matter of concern."
  • Discuss how and when mold fluorescences under UV light
  • Prevention of mold should be stressed more and Health and Safety should be more thoroughly discussed
    • Do some fact checking on the statement about diabetes and mold.
    • Discuss sensitivity to mold with prolonged exposure. (Conservators who treat mold often)
  • Fumigation section does not mention any options of freezing or anoxia.
  • In the section on response - A timeline for mold during a disaster is needed (or linked to in disaster specific resources.
  • Review sections on identifying mold species, when it is advisable, and the suggestions given for how to go about that (the several scattered sections on "how to cultivate" seem unnecessarily extensive - kkelly).
  • Discuss gamma radiation (possibly under a "current research section").
  • Discuss biological safety cabinets as an alternative to fume hoods.
  • Review section on alterations to vacuum equipment and "mini-vacuums". Consider restating these as a less-preferred option to a HEPA filter, variable suction vacuum. Vacuum cleaner technology has improved significantly since 1994.
  • Either update the discussion of PPE or [even better] link to more comprehensive resources.
  • The section on Conservation Treatment: Photographic Materials is weak. It either needs better information or we should instead link to a better resource.
  • The section on Conservation Treatment: Treatment of Structural Damage could be built up more
  • Discussion of 70-30 ethanol to water mixture for cleaning equipment.
  • More discussion of enzymes in stain reduction?
  • The discussion of why we don't use certain fumigants is good, but could be brought up to date with more recent citations (and support for statements about 3% loss of paper strength caused by EtO).
  • PMG has page on Mold with very good annotated bibliography. Consider collaboration with them? PMG Mold and Foxing Remediation--Denise Stockman (talk) 15:44, 14 April 2015 (CDT)
  • The EPA draws a useful distinction between mold clean-up for less than 10 sq. ft. and more than 10 sq. ft.: http://www2.epa.gov/mold/mold-cleanup-your-home.--Kkelly (talk) 12:31, 18 November 2015 (CST)

Suggested Addition to the Section on Mold Response

Below this point are some proposed changes to the Section on Mold Response:--Kkelly (talk) 14:50, 18 November 2015 (CST)

Assess the Situation and Plan your Response

When mold is observed or suspected on collection items or in storage areas, you should first assess the cause of the outbreak and its size before beginning any recovery actions. The cause of the mold outbreak is important - a water leak requires immediate action while old, inactive mold may not. A large mold outbreak may require assistance from a mold remediation expert, and the area around a medium sized outbreak may need to be contained before recovery actions begin.

Cause of Mold Outbreak

When mold is discovered on a collection item it indicates a possible environmental problem, particularly if the mold is active. Refer to the section on identifying active vs. dormant mold for more on this distinction. You should inspect the area for sources of water (leaks, condensation, etc.) and measure the humidity in the space. High humidity and elevated temperatures lead to mold growth, and these conditions must be changed as soon as possible to prevent prevent further damage to collection materials. Immediate steps may include eliminating sources of water, installing dehumidifiers, or increasing air flow (see more in the section on environmental control below).

If you find inactive mold, the cause of the mold growth may no longer be clear. You should ensure that the humidity remains low, but proceed with recovery actions. All mold, active and inactive, poses a risk to health and requires the appropriate level of PPE and containment.

Size of Outbreak

The following discussion is based on the EPA's 2008 publication Mold Remediation in Schools and Commercial Buildings and the American Conference of Governmental Industrial Hygienists 1999 book Bioaerosols: assessment and control. Both titles are listed in the Mold Annotated Bibliography. ***add source for responding in a library situation***

The EPA gives guidelines for mold remediation for three sizes of mold incident, based on total surface area affected: small (less than 10 sq. ft.), medium (between 10 sq. ft. and 100 sq. ft.), and large (more than 100 sq. ft.). The table below provides guidelines for what level of personal protective equipment and level of containment are appropriate for the different levels.

Guidelines for Remediating Building Materials with Mold Growth Caused by Clean Water
Size of Mold Incident Personal Protective Equipment Containment
Small (less than 10 sq. ft.) Minimum None Required
Medium (between 10 sq. ft. and 100 sq. ft.) Limited or Full Limited
Large (more than 100 sq. ft.) Full Full
Definitions: * Minimum PPE: Gloves, N-95 respirator, and goggles/eye protection
* Limited PPE: Gloves, N-95 respirator or half-face respirator with HEPA filter, disposable overalls, goggles/eye protection
* Full PPE: Gloves, disposable full body clothing, head gear, foot coverings, full-face respirator with HEPA filter.
* Limited Containment: Use polyethylene sheeting ceiling to floor around affected area with a slit entry and covering flap; maintain area under negative pressure with HEPA-filtered fan unit. Block supply and return air vents within containment area.
* Full Containment: Use two layers of fire-retardant polyethylene sheeting with one airlock chamber. Maintain area under negative pressure with HEPA-filtered fan exhausted outside of building. Block supply and return air vents within containment area.

These are guidelines for mold remediation of building materials, but they can be a useful resource for institutions or individuals as they plan for mold remediation of collections materials. For example, an institution may decide that up to 25 moldy books can be handled in-house with limited PPE and full containment in plastic bags, followed by treatment in a fume hood. 200 moldy books, however, would lead them to evacuate the room and consult a mold remediation specialist whose staff will be required to use full PPE and full containment.

Environmental Control

As discussed in the section "What is Mold", mold can grow wherever environmental conditions favor it - generally high humidity and elevated temperatures. The topic of environmental control is not within the scope of this chapter (see the AIC wiki pages on Environmental Guidelines, Environmental Monitoring, and Environmental Control in Exhibits for more in-depth discussion. Here we will focus on some useful techniques for short-term environmental control to inactivate mold prior to treatment and to prevent further damage.

Stop Mold Growth

Inactivation steps are fungistatic procedures undertaken to stop active mold growth and
Proper environmental maintenance is universally agreed to be the most effective means of preventing and controlling fungal growth. Reducing humidity and increasing air flow inactivate and effectively kill fungal growth. Inactivation by changing environment is a fungistatic method. Drying, cleaning and correcting the environmental conditions which encouraged growth are considered sufficient treatment. Fungitoxic methods, the use of toxic chemicals, applied topically or via fumigation to attempt to kill spores, is no longer considered necessary or appropriate, except for very serious outbreaks.

Possible causes for Elevated Humidity:

  • problems in the air handling system, particularly overfilled drip pans under condensation units or breakdown in humidification systems.
  • pipe leak or a burst pipe.


The first steps are to:
  1. Isolate affected materials. This can be done by placing them in a plastic bag and moving them to a dry area or by quarantining the affected area with plastic sheeting and reducing air circulation between the affected area and the rest of the building.
  2. Locate the source of humidity. Look particularly for building failures (leaky pipe, blocked gutters, etc.) and HVAC failures (heat exchange coils, drip pans, etc.).
  3. Lower the humidity and increase air circulation. Fix or adjust the HVAC if it can dehumidify the air. Thermostatically controlled or fan coil systems often cool the air without removing sufficient moisture and can make the situation worse. Turn them off if necessary and use dehumidifiers. Use fans to circulate the air in the affected area. In the case of a major system failure, immediately contract with a desiccant drying service to install emergency equipment to dry out the affected area. These services should be listed as resources in disaster plans.
If the humidity and moisture content of the objects can be lowered quickly and effectively, this may be adequate to inactivate the mold. If these procedures are inadequate in stopping mold growth, there are several options:

Reduce Humidity in Affected Rooms or Buildings

  • Install dehumidifiers
  • Increasing air circulation
  • contract with a disaster response company that can provide desiccant drying. With this method, moist air is pumped out of an affected area and dry air is pumped back in.


Dry Individual Items (see more <<here>> and <<here>>

  • fan books, interleave materials with blank newsprint, use fans to circulate air, etc.
  • Freeze the material using standard disaster recovery procedures. Freezing will inactivate the mold and prevent further damage. Material can then be vacuum freeze dried or thawed and air dried when circumstances permit.

Some materials cannot be safely frozen and special precautions must be taken when handling some wet media. See <<here>> for cautions about photographs, etc.

UV light exposure

  1. Expose the affected material, for a period under 30 minutes, to sunlight or artificial source with a high ultraviolet light content. UV light acts as a fungistat, particularly when combined with drying. Active mold usually responds to this treatment and begins to show visible signs of change within ten minutes. Because paper base materials are damaged by UV light, exposure should be minimized.

Gamma Radiation

DELETE THIS ONCE YOU HAVE A GOOD LINK
The preferred method of recovering photographic materials is to air dry (preceded by soaking in cold water if items have started to stick together). For large quantities requiring mass recovery techniques, photographs may be frozen, then thawed and air dried or if necessary, vacuum freeze dried. Vacuum thermal drying is not recommended for photographic materials. Unlike vacuum freeze drying in which ice sublimes away during the below freezing drying cycle, vacuum thermal drying introduces heat during the drying cycle which causes stacks of photographs to fuse together. Because of their poor recovery rate after immersion in water, or after any type of freezing process, collodion photographs (tintypes, wet plate negatives, ambrotypes) should be immediately air dried. (See Hendricks and Lesser, 1983 and Albright, 1992.)


DELETE THIS ONCE YOU HAVE A GOOD LINK

Micro-environments

In the workplace, we often encounter moldy materials presented for conservation or we may be asked to participate in cleaning up a “mold bloom” at a site where something has created conditions conducive to a rapid build-up of mold on a variety of materials in situ. Experience has shown that the conservator, with proper training and personal protective measures, can usually handle the restoration of an occasionally moldy item. It is the large scale mold bloom that seems to appear overnight which presents a fairly difficult challenge to the conservator for safely restoring the materials. However, if the reasons and conditions which caused the mold bloom to occur have not been addressed, the stage will be set for a reoccurrence. It is imperative that the source of the moisture problems be found and corrected prior to returning conserved materials to the location from which they came. What are some of the causes for a mold bloom to appear?
Often a malfunction in the air handling equipment results in prolonged periods of high humidity and a resultant mold bloom. In order to increase humidity in a space, some systems are equipped to put steam or water vapor into the airflow during periods of low humidity. Sometimes, because of calcification, these valves and steam jets get stuck in the open position and continuously inject steam into the air flow, elevating humidities for long periods of time. Until the mold bloom appears, often staff members are unaware of this type of malfunction.
Another situation which may place huge amounts of moisture into the air of a space may be caused by an air handling condensing unit filling its drip pan with water. The drain line may be clogged or improperly designed so that the drip pan becomes a “swimming pool.” The air flow then directly and constantly adds humidity to the space housing the collections. Again the mold bloom lets everyone know that “something's wrong” somewhere in the air handling system.
Another type of event which leads directly to a mold bloom is a pipe leak or a burst pipe. If materials in this area are wetted, the mold will first appear on the outside of the materials and will soon grow into the interior. Even if materials are not directly wetted, the elevated humidity in this micro-environment may produce a mold bloom. The burst pipe or leak situation requires quick action to prevent the mold from growing through bound volumes and “sticking” the pages together. If the leak is not discovered in time, and materials are wetted, mold will grow into and through the substrate, making conservation problems much more difficult to resolve. Wet materials should immediately be frozen to hold the mold in check until decisions can be made about reclamation. Vacuum freeze-drying of materials may be required prior to conservation work on the materials.
The last event which results in catastrophic mold growth is a fire. Wet materials soon grow so much mold that conservation may become impossible. Immediate freeing of wet materials is mandatory in such a case. Decisions can then be made about the value of the damaged collections, which ones can be saved, the amount of conservation required, the costs involved for salvage operation, and which materials should be vacuumed freeze-dried.

==

Dehumidifiers

Fans

Containment

Whenever possible, materials should be cleaned in a contained area to reduce the spread of spores to other areas of a lab or facility. For a small amount of mold or in situations were containment is impractical, it may be possible to clean the moldy object outside.

In-situ Containment

An isolation booth or make-shift fume hood can be created with plastic sheeting, negative pressure, HEPA filter fan. The EPA describes two levels of containment:

  • Limited Containment: Use polyethylene sheeting ceiling to floor around affected area with a slit entry and covering flap; maintain area under negative pressure with HEPA-filtered fan unit. Block supply and return air vents within containment area.
  • Full Containment: Use two layers of fire-retardant polyethylene sheeting with one airlock chamber. Maintain area under negative pressure with HEPA-filtered fan exhausted outside of building. Block supply and return air vents within containment area.

Fume Hoods

A booth that moves air from the room, across the working area, and then vents out...

Biological Safety Cabinets

A booth that recycles air back into the room through a HEPA filter vacuum. Requires filter maintenance and can only be used for particulates like mold or dust, not solvents.

Personal Protective Equipment

Respirators and Masks

Anyone participating in mold removal that involves more than a few minor spots of infestation needs to take serious precautions. A respirator with high efficiency particulate air (HEPA) filter should be used. Dust masks are not adequate because mold spores are so small they pass through them easily.

Gloves

Protective clothing should also include, at a minimum, disposable gloves and safety glasses.

Other Protective Clothing

Coveralls and protective hair and shoe covers should be used whenever the mold removal procedure releases a significant quantity of mold spores into the air. These items should be discarded or washed in disinfectant at the end of each mold removal session. Personnel involved should shower as soon as possible.

Levels of PPE

  • Minimum PPE: Gloves, N-95 respirator, and goggles/eye protection
  • Limited PPE: Gloves, N-95 respirator or half-face respirator with HEPA filter, disposable overalls, goggles/eye protection
  • Full PPE: Gloves, disposable full body clothing, head gear, foot coverings, full-face respirator with HEPA filter.

Fungicidal vs. Fungistatic Measures

A wide variety of fungicidal and fungistatic materials and procedures have been used to control mold. Fungicidal materials and procedures, such as ethylene oxide, kill mold and mold spores with a high degree of effectiveness and reliability. Fungistatic materials and procedures, such as thymol and ortho phenyl phenol, inactivate mold and discourage its growth but do not effectively kill it. Fungicidal materials and procedures, and fungistatic materials have been found to be too toxic and/or too damaging to collection materials to recommend their continued use. Also, none of the materials traditionally used impart any residual protection, so materials returned to situations with high relative humidity became increasingly susceptible to repeated mold damage.
Fungistatic procedures, specifically the control of temperature and relative humidity and the provision of good air circulation, are the primary means of preventing and stopping mold growth.
In the event of a major outbreak or an outbreak involving a highly toxic species, outside professionals may advise the use of specialized fungicides that must be applied by a licensed professional. They are most frequently used to disinfect duct work and HVAC systems, but some can provide residual protection to storage areas and collection materials for a limited time. None have been tested for their long term effects on collection materials, so their use is a last resort.

Cleaning Storage Areas and Materials

As part of a mold clean-up, the storage materials and storage area must be thoroughly cleaned. The goal here is to reduce the spore population to safe levels. Boxes that exhibit mold growth should be vacuumed and wiped with a dry or very slightly dampened cloth. All surfaces (shelves, walls, floors, etc.) should be vacuumed and wiped with a Lysol-type fungicide diluted as recommended on the product container. Rugs and drapes should be thoroughly dried, vacuumed and cleaned if necessary. Collection materials should not be returned until the area is dry and the environment is stable.
The HVAC system should be thoroughly inspected. Filters should be changed. Heat-exchange coils, drip pans and duct work should be cleaned and disinfected as necessary.


Outsourcing Mitigation/Treatment

  • Large in-house= when to consult with a remediation company
  • Links to outsourced recovery/mitigation companies.
Small to moderate outbreaks of mold involving a limited number of items can often be handled in-house if no highly toxic species are present. The amount and type of outside assistance required will depend on the resources of the institution or owner and the type of material affected. A major bloom, involving a large area of a collection or highly toxic mold species will require outside professional assistance and advice to stop the mold growth, clean the collection and render the affected area safe for use again. The information in this chapter is applicable to small and moderate outbreaks that do not involve highly toxic species.
It bears repeating that small to moderate outbreaks of mold involving a limited number of items can often be handled in-house if no highly toxic species are present. The amount and type of outside assistance required will depend on the resources of the institution or owner and the type of material affected. A major bloom, involving a large area of a collection or highly toxic mold species will require outside professional assistance and advice to stop the mold growth, clean the collection and render the affected area safe for use again. The information in this section is applicable to small and moderate outbreaks that do not involve highly toxic species.