Preservation 101: Causes of Deterioration
Causes of Deterioration:
There are six main causes of deterioration that an archives face and these are the same for your own private collections of memorabilia, family heirlooms and documents.
Climate is made up of the duo, Temperature and Humidity. High temperature exasperates chemical reactions within materials. It has been shown that for every increase of 18 degrees Fahrenheit (10 Celsius) the chemical activity in most materials will double (except paper which has an estimated doubling for every 10 degrees Fahrenheit or 5.5 Celsius without the need of other factors like light, pollutants, etc).
Humidity (moisture) is the other side of the climate duality. In measuring humidity it is referred too as Relative Humidity (RH). This is the amount of water vapor, expressed as a percentage, which the air can hold at any given temperature. The higher the temperature (air expands) the more water vapor (moisture) it can hold. We have all felt the difference that humidity can make. If for example you are in Los Angeles with a temperature of 80 degrees and a RH of 30% we say it is warm and pleasant. However, if you are in Florida with the same temperature and a RH of 95% it feels hot and sticky, yet the temperature is still 80 degrees Fahrenheit. The amount of humidity in the air is important with regard to preservation due to the fact that humidity creates the critical function in acid or chemical formation. The higher the humidity the faster damage will occur. Rapid fluctuations in both temperature and humidity will also increase deterioration via the expansion and contraction on organic materials placing structural stress on an item especially paper based products. Of the two, humidity is the most destructive and hardest to control. The higher the humidity the more it will encourage the formation of molds, mildew, acids, insect activity and can cause coated papers to stick together and water soluble inks to offset. If on the other hand the humidity is to low it can make items became brittle or shrink causing warping. All or any of the above factors will contribute to the breakdown of organic based items. It is therefore critical that temperature and humidity be stabilized in a preservation environment.
Abuse is the acts carried out by people (sometimes well intentioned) resulting in damage or loss. Examples of abuse can be; rough handling, writing on items, spilling drinks, food, etc. While most abuse comes from careless handling it can also take on the form of theft, vandalism and inappropriate preservation treatments. It is therefore critical that proper handling, storage, conservation methods and security be established and followed.
Biological damage is made up from Fungi (molds and mildew), insects and rodents. Warm, humid, dark conditions with low airflow and a climate above 75 degrees Fahrenheit (24 Celsius) and a relative humidity above 65% make for an attractive place to feed and inhabit. Mold spores are everywhere and are ready to take up residence whenever favorable conditions present themselves. Molds can also live in low temperature but need-elevated humidity (you may have seen this in your refrigerator) to thrive. Molds/fungi feed on cellulose, starch, adhesives, gelatin and sizing, all found in books, photographs and paper products. These molds, etc, can weaken items and leave permanent stains or destroy all together.
Insects and rodents feed on much the same material as fungi. Rodents and insects prefer dark, damp, warm places to live and eat and are most active at night, so for the most part remain unseen by humans while causing irreversible damage or total destruction. Some of the more common insects to cause damage are; silverfish, termites, beetles (sometimes called bookworms) and cockroaches. Rodents such as rats, mice, and squirrels can eat entire collections or use them to make nests. The droppings from rodents are corrosive and will leave permanent stains on materials they come in contact with.
Light provides the catalyst for complex chemical reactions within an item and while we have all heard of ultraviolet light (UV) as being destructive, (and it is) it should be understood that all light will cause damage to paper, photo's and all other organic materials. One of the major concerns about light is that it is cumulative and irreversible. We have all seen light damage in the form of faded photo's, paper or other items bleached or changing color like a newspaper left in the sun for a couple of days turns brown. Remember it is the way light causes oxidization and the chain reaction of chemical interactions along with climate conditions that cause damage. Natural light (sunlight) is the more damaging as it has a higher UV and is brighter than artificial light sources like fluorescent or incandescent lamps.
Pollutants are made up of two types. Particulates (soot, dust, dirt) and Gases (sulfur dioxide, nitrogen dioxide, peroxides and ozone). Gases are catalysts for forming acids. Particulates can carry chemicals to form acids and are abrasive, causing breakdown and disfiguring.
Disasters come from, Water, Fire and Natural disasters (act of God). Water can be introduced from leaking steam or water pipes, fire sprinkler systems, flood and rain. Fire is straightforward to understand and is always catastrophic. Natural disasters occur from Flooding, Hurricanes, Tornado's and Forest fires.
Close: Any or all of the above conditions if left unchecked can and will cause harm to your precious items. Nothing ultimately is permanent in this world but we can be prudent in our actions so as to extend the useful life of important objects so others can learn from and appreciate the value and historical lessons they provide.
Links are provided for further reference
Conserve O Grams put out by the National Parks Service. These are provided, as they are in easy to download PDF format and cover in layman's terms for the most part Conservation and Preservations needs for a wide variety of items.
Also, the Bhaktivedanta Archives have a program to help you with your Srila Prabhupada collection. If you have an original document and or audio recordings we will conserve/preserve them for you and return back to you so long as we can make a copy of the item for the archival collection. We offer this program free of charge for small items or quantity, but always welcome donations for this important service. See page 2.
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