Figure 1: Concentrations of residual chlorine in the hydrogen molecule water generated by electrolytic apparatuses containing with whole or half amount of tap water. Note: Contents of residual chlorine in the post-electrolytic hydrogen water which was prepared by diverse types of electrolysis apparatuses as evaluated by OTT-chromaticity method. (A) Osaka City-supplied Tap water was poured up to the full scale into a tank of the apparatus, and electrolyzed for 30 minutes according to the manufacturer’s protocol, and then was quantified for residual chlorine by OTT method. The calibration curve was obtained using authentic chlorine, and extrapolated with OTT-to-holoquinone-conversion-based chromaticity at the absorption maximum of 435 nm for each yellowish sample. (B) Tap water was poured up to a half or full scale into the tank, and manipulated as in A. The safety standards for dissolved chlorine level (5 mg/L) according to World Health Organization guidelines are indicated by arrowhead. All concentrations of residual chlorine in the hydrogen molecule water generated by electrolytic apparatus containing with whole or half amount of tap water were below the safety standards (5 mg/L). Data are expressed as the mean ± SD, and study was executed three times. B: Bliss water; F: Flax Pocket; L: Lita dual bottle; OTT: orthotolidine; T: tap water.