Volume 6, Number 2, May 1984, pp.13-14
The composition, nature, trade name and health implications of hazardous materials are the primary kind of information conservators frequently need. Happily it isn't always necessary to trace information from articles in the library. Easily referenced material is available and this article cites a few sources which should be helpful. This is only a partial listing and the opinions offered are my own.
By now the work done by the Center for Occupational Hazards should be familiar to all conservators. The Center's newsletter Art Hazards News and many of their other publications offer a wealth of information on the hazards of many of the materials conservators work with. The book "Artist Beware," by Michael McCann, Ph.D., founder of the Center, is of great value to the conservator.
The Merck Index, an encyclopedia of chemicals and drugs published by Merck & Co., Inc. is another "must have." This index contains alphabetic listings for 9856 materials with a cross referenced list of common names. Brief descriptive material on the chemicals include structural formula; trade names and synonyms; a short history of the chemical; and how it is made. Of special interest to the conservator are health effects and health related information which is given.
Within the conservation community, the 1980/1981 issue of The Paper Conservator, published by the Institute of Paper Chemistry, is a masterpiece. Volumes 5 & 6, "Safety and Health in the Paper Conservation Laboratory," edited by Guy Petherbridge and J. Malcolm Harrington, contains 12 articles. Included is an in depth listing of chemicals most often used in the conservation laboratory which are arranged in a safety data sheet format.
Material Safety Data Sheets (MSDS) are the information sheets manufacturers supply which detail the health, safety and fire hazards of a commercial product. Although these list only the components which are hazardous, this information can be a valuable clue to decoding commercial products.
MSDSs are subdivided into 10 parts. Section One identifies the product by its chemical name, commercial name and formula. Hazardous components are inventoried and the percent of their weight in the formulation is given. Physical data is tabulated, including the boiling point, specific gravity and evaporation rate. There is a section on fire and explosion hazards, flash point, flammable limits and how to combat a fire. Health hazards are listed with TLVs or TWAs of the components. Emergency first aid procedures are listed. There is a section on reactivity data, including general stability, known incompatibilities and hazardous decomposition products. Another section describes how to clean up a spill or leak and how to dispose of collected material. There is always a section on what protective equipment should be worn when handling the product and a final section lists any other precautions which should be taken.
Due to obvious legal considerations, disclosure of proprietary information is kept to a minimum. Generally, while acute toxic information is well covered, information on suspected carcinogens is not presented.
A good, inexpensive, but limited source of information is the catalog for MCB Chemicals (it's one of my favorites.) Each chemical that MCB sells is listed with its structural formula, acute toxicity information and DOT classification. The toxicity information is given in terms of LD50s, that is the lethal dose, 50% kill. The LD50 is the extrapolated amount of chemical administered to a group of test animals which would kill half of them. Included is the identity of the target animal and how the chemical was administered.
For example, the listing for acetone is:
TXDS: orl-rbt LD50: 5300mg/Kg orl-hmn LdLo: 50mg/Kg ihl-hmn TCLo: 500ppm
This tells you that if acetone is given to rabbits, in the amount of 5300 milligrams per kilogram of body weight, half of the test population would be killed. For humans, the lowest published lethal dose for orally administered acetone is 50 mg per kilogram of body weight. The lowest published toxic concentration for inhalation for humans is 500 parts per million.
The DOT classification for toluene is:
DOT--(Toluene)FL[FP 40 F(cc)]
This says that toluene is listed by the Department of Transportation as a flammable liquid which has a flash point of 40° Fahrenheit by the closed cup method. (Flash point is the lowest temperature at which a solvent gives off enough vapors to form an ignitable mixture in the air.)
At the back of the catalog there is a 43 page section on laboratory safety. It includes information on groups of hazardous materials, many of which are not of interest to conservators. Information on waste disposal, on how to cope with spills, on how to protect ones self and on storage safety is listed.
The MCB Catalog should be available free of charge. A current price list is inside. An out of date catalog works just as well and the prices are nostalgic.Chris Stavroudis