Before proceeding any further, it would helpful to be define a  number of health-related terms. The following are working definitions and are  not intended to be exact legal or medical definitions. Also, the definition of  “toxic” with regard to art and craft materials is being redefined by new  legislation in a few states to include suspected carcinogens, carcinogens, and  teratogens. At this time such changes are not yet universally accepted and the  following terms have been defined as they have been in the past.

Adequate  ventilation is not just opening all the doors and windows. It is having constant exchanges  of air, with fresh air replacing the contaminated air approx­imately every  fifteen to twenty minutes. This is generally accomplished only by being outdoors  or by having a general ventilation system.

Acute means a single pronounced event, such as an “acute exposure.” In terms of health  an “acute illness” would be an immediate and severe reaction by the body.

Chronic is long-lasting or repeated, as in “chronic exposure.” In terms of health, a  “chronic illness” is an ongoing illness or one that surfaces from time to time.

Carcinogens are substances that will produce cancer.

General  ventilation is a system whereby the hazardous materials in the air are reduced through  dilution. An exhaust fan is set up as the sole exit for the con­taminated air,  and an entrance for a supply of fresh air is established as far away from the  fan as possible. This supply of fresh air traveling from one side of the room to  the other will dilute the contaminates that accumulate in the air in the room.

Highly toxic means that serious injury or death will result from contact or absorption of a  small amount, such as a mouthful, by a healthy adult. Inorganic refers  chemically to compounds that do not possess hydrocarbons (a water-carbon  chemical structure), but do include oxides and sulfates of carbon. Water, nitric  acid, calcium carbonate, and alum are examples of inorganic chem­icals used in  the process of making artists’ materials or included in the product itself.

Local  ventilation is a system whereby the hazardous material are removed before they have an  opportunity to disperse into the room’s air. Most local ven­tilation systems  bear a certain resemblance to a large vacuum cleaner, and often contain a hooded  area in or under which the work is performed.

Moderately  toxic means that temporary to permanent minor injury will result from contact with, or  absorption of, a small to moderate amount by a healthy adult.

Mutagens are substances that will produce genetic changes.

Nontoxic  means that no detectable injury will occur from contact with, or absorption of, small  to moderate amounts by a healthy adult. This term does not mean nonhazardous.  Carcinogens and mutagens are rarely considered in non­toxic labeling. And, a  nontoxic substance may produce a toxic effect when com­bined with other  substances, or may have a cumulative effect from long-term chronic exposure.

Organic refers chemically to all carbon-based chemicals. Benzene, toluol, turpentine,  and carbon tetrachloride are examples of common organic solvents that contain  carbon and are used in artists’ materials.

Slightly  toxic means that temporary minor injury will result from contact with, or absorption  of, a small to moderate amount by a healthy adult. Larger quan­tities of  exposure could, however, cause greater damage.

Synergistic  effect is when two or more substances cooperate to produce an effect that is greater  than the effect that would have been produced had the substances acted  independently of one another. Drinking alcoholic beverages while working with  solvents is a good example.

Teratogens are substances that will cause severe birth defects or malformations. Total Body  Burden is a term that refers to the burden on the defense mech­anism of the  body, or the cumulative effects of a particular substance on the body. For  example, the body may be able to detoxify itself from infrequent exposures to  moderate amounts of a toxin, yet be unable to deal with frequent exposures to  small amounts of the same material. The body often needs time to recover from an  exposure, and the cumulative effects of small exposures can add up rapidly to  overwhelm the body’s defenses.

Toxic means poisonous, or having the ability to destroy life or health on contact or  by absorption. There are various degrees of toxicity, such as high, moderate,  slight, and nontoxic. The degree of toxicity is determined not only by the  nature and the quantity of the substance but by the type of contact or  absorption. For example, genuine cadmium red, although an irritant, is  considered nontoxic when in contact with the unbroken skin. However, it is  highly toxic if the dust from the dry pigment is inhaled or ingested, even in  such small a quantity as a mouthful.

Excerpts  from ART HARDWARE: The Definitive Guide to Artists’ Materials, by Steven  Saitzyk © 1987 All rights reserved.  Reproduction forbidden without written  permission.