TABLE 1. Summary of source, typical industrial use, and chemical properties for all solvents tested. (a) mmHg at 25° C, (b) centipoise/second at 25° C, (c) dyn/cm at 25° C, (d) air = 1. Asterisks (*) are values at 20° C, nd is not determined, and nl is not listed. All chemical properties are from SDS and technical data provided by the manufacturer.
| Name | Source | Typical Use | Vapor pressure (mmHg) |
Viscosity (cP) |
Surface tension (dyn/cm) |
Relative vapor density (air = 1) |
Residue | Cal/O SHA PEL |
| AeroTron™-100 | Reliance | vapor degreaser | 395.2 | 0.49 | 19.5 | 5.2 | <10 ppm | 200 ppm |
| Novec™ 73DE | 3M | vapor degreaser, liquid degreaser | 263* | 0.384 | 19.9 | 5.2 | 0 ppm | 200 ppm |
| Ecolink™ 1171 | Ecolink | liquid degreaser | 44.1* | nd | nd | >5 | nd | 200 ppm |
| 2-butoxyethanol | Consolidated Chemical & Solvents | solvent for varnishes, lacquers, etc. | 0.874 | 2.9 | 27.4 | 4 | nd | nl |
| (+)-limonene | Various, 99- 100% | liquid degreaser | 1.98 | 0.85 | 26 | 4.7 | nd | nl |
| 1-bromopropane | Reliance | nPB vapor degreaser | 134 | 0.5 | 26.1 | 4.3 | <10 ppm | 5 ppm |
TABLE 2. Ease of surface asphaltic matrix removal and average preparation time by solvent and treatment method.
| Name | Method | Ease (Mechanical Effort) |
Average Time (minutes) |
| AeroTron™-100 | Soak | Low | 65 |
| Manual | Moderate | 121 | |
| Novec™ 73DE | Soak | Low | 68 |
| Manual | Moderate | 164 | |
| Ecolink™ 1171 | Soak | High | 77 |
| Manual | High | 145 | |
| 2-butoxyethanol | Soak | High | 61 |
| Manual | High | 130 | |
| (+)-limonene | Soak | High | 72 |
| Manual | High | 123 | |
| 1-bromopropane | Soak | Low | 31 |
| Manual | Low | 218 |
TABLE 3. Summary of solvent effects after preparation and long-term observations.
| Name | Preparation Observations | Long-term Observations | |||||
| Surface Damage (# of Fossils) |
Surface Appearance |
Odor | Color | Mass | Asphalt Exudation |
Visible Degradation |
|
| AeroTron™-100 | 4 | Inconsistent | Weak | No change | No change | Minor | None |
| Novec™ 73DE | 1 | Excellent | None | No change | No change | Minor | None |
| Ecolink™ 1171 | 4 | Glossy, dried-out at damaged areas, dark | Moderate | No change | No change | Moderate | Minor |
| 2-butoxyethanol | 0 | Dark, oily, plastic-like | Strong | No change | No change | Minor | None |
| (+)-limonene | 3 | Glossy, dried-out at damaged areas | Strong | No change | No change | Major | Significant |
| 1-bromopropane | 1 | Dried-out at damaged areas | Weak | No change | No change | Moderate | None |
TABLE 4. Crania manual preparation time and solvent volume. All specimen numbers are prefixed by LACM. Crania are classed as complete (majority of cranium present), anterior (frontals, parietals, and occipitals missing), or posterior (premaxillae, maxillae, and palatines missing). Abbreviation nr indicates not recorded.
| Specimen # | Taxa | Crania | Deposit | Solvent | Preparation time (hr) |
Preparation solvent (mL) |
| P23-41921 | A. dirus | posterior | P23-13 | Novec 73DE | 25.1 | 208 |
| P23-41926 | C. latrans | complete | P23-13 | nPB | 44.6 | nr |
| P23-41929 | A. dirus | posterior | P23-9 | nPB | 17.8 | 480 |
| P23-41930 | A. dirus | complete | P23-9 | nPB | nr | nr |
| P23-41931 | A. dirus | complete | P23-9 | Novec 73DE | 26.3 | nr |
| P23-41932 | A. dirus | complete | P23-9 | Novec 73DE | 50.4 | 510 |
| P23-41936 | A. dirus | anterior | P23-14 | Novec 73DE | 13.6 | 225 |
| P23-41937 | A. dirus | posterior | P23-14 | Novec 73DE | 16.5 | 306 |
| P23-41940 | A. dirus | complete | P23-14 | nPB | 63.7 | 750 |
| P23-42371 | C. latrans | complete | P23-9 | Novec 73DE | 28.6 | 306 |
| R66366 | A. dirus | posterior | Pit 91 | Novec 73DE | 13.2 | 161 |
TABLE 5. Cranial preparation comparison. All specimen numbers are prefixed by LACM. Crania are classed as complete (majority of cranium present), anterior (frontals, parietals, and occipitals missing), or posterior (premaxillae, maxillae, and palatines missing). Dash indicates not applicable.
| Specimen # |
Taxa | Crania | Deposit | Preparation Type |
# fragments |
% of Cavities with Retained Matrix | |||
| Major | Dental alveoli | Foramina | Non-morphological | ||||||
| P23-12787 | A. dirus | complete | P23-1 | soak | 6 | 0% | 0% | 3% | 0% |
| P23-17329 | C. latrans | complete | P23-1 | soak | 4 | 0% | 0% | 10% | 0% |
| P23-18908 | A. dirus | complete | P23-1 | soak | 13 | 0% | 0% | 14% | 0% |
| P23-18909 | A. dirus | complete | P23-1 | soak | 15 | 0% | 0% | 7% | 4% |
| P23-18910 | A. dirus | complete | P23-1 | soak | 1 | 0% | 0% | 6% | 0% |
| P23-18911 | A. dirus | complete | P23-1 | soak | 8 | 0% | 0% | 3% | 0% |
| P23-18912 | A. dirus | complete | P23-1 | soak | 29 | 0% | 0% | 3% | 0% |
| P23-42850 | C. latrans | posterior | P23-9 | soak | 13 | 0% | - | 40% | 0% |
| P23-42851 | C. latrans | posterior | P23-9 | soak | 16 | 0% | - | 0% | 0% |
| P23-5351 | C. latrans | complete | P23-1 | soak | 31 | 0% | 0% | 0% | 0% |
| P23-7388 | A. dirus | complete | P23-1 | soak | 2 | 0% | 0% | 7% | 5% |
| P23-8099 | C. latrans | complete | P23-1 | soak | 6 | 0% | 0% | 29% | 6% |
| P23-8580 | A. dirus | complete | P23-1 | soak | 15 | 0% | 0% | 0% | 0% |
| P23-41921 | A. dirus | posterior | P23-13 | manual | 1 | 100% | - | 100% | 100% |
| P23-41926 | C. latrans | complete | P23-13 | manual | 2 | 100% | 100% | 100% | 100% |
| P23-41929 | A. dirus | posterior | P23-9 | manual | 0 | 100% | - | 100% | 100% |
| P23-41930 | A. dirus | complete | P23-9 | manual | 7 | 100% | 100% | 94% | 100% |
| P23-41931 | A. dirus | complete | P23-9 | manual | 2 | 100% | 100% | 93% | 73% |
| P23-41932 | A. dirus | complete | P23-9 | manual | 7 | 100% | 100% | 100% | 100% |
| P23-41936 | A. dirus | anterior | P23-14 | manual | 2 | 100% | 89% | 100% | 100% |
| P23-41937 | A. dirus | posterior | P23-14 | manual | 12 | 100% | - | 100% | 100% |
| P23-41940 | A. dirus | complete | P23-14 | manual | 29 | 100% | 100% | 83% | 0% |
| P23-42371 | C. latrans | complete | P23-9 | manual | 6 | 100% | 100% | 100% | 100% |
| R66366 | A. dirus | posterior | Pit 91 | manual | 0 | 100% | - | 100% | 100% |
