1]：Sealed vessel2]：Sealed vessel+SPCC
3]：Vessel with ventilation
4]：Vessel with ventilation+SS400
5]：vessel with ventilation+SPCC
Test plece, SS400：Rolled steel
SPCC：Hot rolled steel plate
Chttges of the obsorbance of each sample are shown in Fig.2. The ratios of the changes in all of the samples of AB9,AB90,AR52 and SB5 were 4.3% at most.10% 1s the threshold of visible colorchange.On the other hand,the ratio of the change in a samlple of AY73 was more than 40%.AY73 has thermochromism, and exhibits the symptom of color in a basic solvent.As soda glass vessels were used in the test, it seemed that these samples became basic somewhat.
The changes of the absorbance wavelength in the samples were O.6% at most.Chemical analyses of the samples after thestorage test indicated no abnormal results.
Fig.2 Change ofabsorbance
Mutagenicity test
The mutagenic activitles of dyes were tested using Salmonella typhimurium TA100, TA1535, TA98, TA1537 and Escherichia coli WP2uvrA.AB9, AR52and AY73 seemed to be safe in regards to mutagenicity in terms of the desk consideration Among these, however,AY73 was excluded for its bigger change of absorbance in the storage test. Thus,
mutagenicity tests were conducted on AB9 and AR52 only. Materials and method are shown in brief in the following.
Strains
Base pair substitution mutagen
TA100,TAl535,WP2uvrA
Frame shift mutagen
TA98,TA1537
Method
1.Plate incorporation method
2.Concentrations of test substances
5.0, 2.5, 1.25, 0.625, 0.313, 0.156 mg/100μl (together with -S9mix and +S9mix)
3.Criteria of mutagenicity
Positive： The number of revertant colonies in samples is twice or more than that of revertant colonies in the negative control, and the relationship between dosage and response is recognized.
Positive： The number of revertant colonies (pseudo) in samples is one and a half times to twice that of to the negative control.
Negative： The number of revertant colonies is one and a half times or less than that of the negative control.
Experimental results
