Fig. 3 shows the ratio of the number of revertant colonies in test samples containing AB9 and the negative control.
The number of revertant colonies in test samples were one and a half times less than the number in the negative control. A relationship between dosage and resoponse was not recognized. Thus, AB9 proved to be mutagenicity-nagative. Fig.4 shows the experimental results in the case of AR52. It is considered that AR52 is also negative against mutagenicities.
Exhaust emission tests
Selection of dye for tests
One dye was selected for an exhaust emission test and a fleet test based on desk considerations and the results of experiments. Results are summarized on Table 4.
AR52 is more expensive and its color is like gasoline. AY73 exhibited a change of absorbance in the storage test. SB5 contains halogen in its molecule. AB9 and AB90 have a potential for serving as a dye for methanol. AB9 is currently used as a food additive, and it was confirmed that AB9 was negative against mutagenicities in our mutagenicity test. Thus AB9 was selected as a dye for an engine exhaust emission test and a fleet test.
Experimental conditions
An exhaust emission test was conducted on a chassis dynamometer using a methanol truck with a payload of 2 tons. The Japanese 10-15 mode for light-duty vehicles was used for a test cycle. Table 5 shows the main specifcation of the vehicle tested.
Experimental results
Test results are shown in Fig.5. There were no clear difference between methanol and dyed methanol. This means that methanol containing 1 ppm AB9 has no inf1uence on the exhaust emissions of a methanol engine.
