In consumer information in Japan, an idea of 100% biodegradation of soap which means “soap can be biodegraded completely into H₂O and CO₂ in one day, but about a third of LAS still remained after one month biodegradation” has had a great impact on the difference between biodegradation of soap and that of Linear Alkylbenzene Sulfonate (LAS). In this paper, we studied why and how such disinformative idea has spread out. 35 general consumer books relating surfactant safety and environmental effects were collected and the contents were analyzed. We found that 30 books accuse synthetic surfactants including LAS, and 16 books of which refer to the idea of 100% biodegradation of soap. The source of the idea was ascertained to be one scientific paper, in which TOC based biodegradation data was included and the value for sodium stearate was shown to be about zero in one day. We performed the confirmative test and found that the low TOC value in the paper would have obtained according to the low solubility of the metal soap (calcium stearate or magnesium stearate). The metal soap can be easily removed from the test liquid in the pretreatment for TOC measurement. Additionally, we performed biodegradation test by an oxygen consumption method and obtained the result of 50% of biodegradation in a week for sodium stearate. It can be concluded that the idea of 100% biodegradation of soap is one of disinformation, and the problem occurred by consumer book authors for their incomprehension of the difference between “TOC was zero” and “biodegradation was 100%”.

Considering the diversification of dust cloths on the market, the authors investigated color factors affecting the noticeability of dirt, which would lead to their disposal.
A total of 19 different-colored samples made of towel cloth were shown to 100 subjects, who were instructed to rank the samples in order of the anticipated inconspicuousness of dirt. Subjects were then asked to use 40 patchwork dust cloths made of the same material at home for one month and to rank them in order of the actual inconspicuousness of dirt. The results of the ranking of inconspicuousness of dust cloths before use were then compared with that of dust cloths after use. In addition, subjects were asked to indicate what color they considered ideal for dust cloths and the reason for their choice.
The results showed a strong correlation between evaluations of dust cloths before and after use, and the noticeability of dirt was greater for brighter colors. However, differences were observed for colors for which dirt was difficult to notice. Specifically, dark blue was selected before use, while dark red was selected after use.
Market research showed that many brightly colored dust cloths were commercially available. However, the color evaluated as ideal for dust cloths changed after use as the subjects saw actual dirt on the dust cloths. Therefore, selection of preferred colors or colors which give an impression of cleanliness when purchasing dust cloths was thought to contribute to their earlier disposal.