For volatile chemicals. A cotton ball saturated with the test chemical was placed in a one ounce bottle (10mm x 75mm test tube or similar container). The container was inverted on the test material surface for a period of 24 hours. Temperature of test: 23° +/-2° C (73° +/-4° F). This method was used for the organic solvents.
For non-volatile chemicals. Five drops (1/4cc) of the test chemical were placed on the test material surface. The chemical was covered with a watch glass (25mm) for a period of 24 hours. Temperature of test: 23° +/-2° C (73° +/-4° F). This method was used for all chemicals listed below other than the solvents.
After 24-hour exposure, exposed areas were washed with water, then a detergent solution and finally with isopropyl alcohol. Materials were then rinsed with distilled water and dried with a cloth. Samples are numerically rated as follows:
- No Effect - No detectable change in the material surface.
- Good - Slight detectable change in color or gloss but no change in function or life of the surface.
- Fair - Slight surface etching or severer staining. Clearly discernible change in color or gloss but no significant impairment of surface life or function.
- Poor - Pitting, cratering or erosion of the surface. Obvious and significant deterioration. Objectionable change in appearance due to dis-coloration .
|Chemical Tested*||Method||Black Onyx|
|Acetic Acid 98%||B||0|
|Acid Dichromate 5%||B||0|
|Ammonium Hydroxide, 28%||B||0|
|Chromic Acid 60%||B||2|
|Dichloro Acetic Acid||A||0|
|Formic Acid 90%||B||0|
|Hydrochloric Acid 37%||B||0|
|Hydrofluoric Acid 48%||B||2|
|Hydrogen Peroxide 28%||B||0|
|Tincture of Iodine||B||0|
|Methyl Ethyl Ketone||A||0|
|Nitric Acid 20%||B||0|
|Nitric Acid 30%||B||1|
|Nitric Acid 70%||B||1|
|Phosphoric Acid 85%||B||1|
|Silver Nitrate, Saturated||B||0|
|Sodium Hydroxide 10%||B||1|
|Sodium Hydroxide 20%||B||1|
|Sodium Hydroxide 40%||B||1|
|Sodium Hydroxide Flake||B||1|
|Sodium Sulfide, Saturated||B||2|
|Sulfuric Acid 25%||B||1|
|Sulfuric Acid 85%||B||2|
|Sulfuric Acid 96%||B||3|
|Sulfuric Acid 85%, and Nitric Acid 70%, equal parts||B||3|
|Zinc Chloride, Saturated||B||0|
*Independent Results from Universal Laboratory, Inc., 1726 Commerce St., Garland, TX