Iwanai Onsen No. 5 Well
Analysis UnverifiedIwanai Onsen spreads across the heights of Iwanai, a town facing the Sea of Japan, at the foot of Mt. Iwanai in the Niseko range. The town-owned Well No. 5 is pumped at a generous 290 L per minute and supplied to inns such as Takashima Ryokan below. The water is clear and nearly tasteless and odorless, with a balance of bicarbonate and chloride, and its smooth touch has earned it a reputation as a skin-beautifying bath. At Takashima Ryokan the source flows straight into the indoor bath and a wooden outdoor tub, where fine bubbles rise through the fresh water.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.
A trace component with gentle antibacterial and anti-inflammatory action.
Scores are calculated from mineral analysis data based on the Mineral Spring Analysis Guidelines (Ministry of Environment, Japan). They are unrelated to facility atmosphere or service quality.
▸Note
The temperature, pH and component values shown here are based on the hot spring analysis (source). Actual values in the bath may differ depending on heating, dilution, recycling and filtration. Please check current usage status at the facility.
The source flows straight into the tubs, so it is hotter near the inlet. Pour water over yourself first, and drink water often if alternating between the sauna and outdoor bath.
With 445.5 mg/kg bicarbonate and 176.4 mg/kg metasilicic acid smoothing the skin toward a silky finish, and 170.3 mg/kg chloride helping hold warmth, this water suits both silky skin and restorative warmth after bathing.
The source is close to 50°C. Beware of the heat near the inlet and of dehydration or dizziness when combining the bath with the sauna.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Iwanai Onsen No. 5 Well
- Spring type
- Sodium Bicarbonate and Chloride Hot Spring
- Old spring type name
- 含食塩－重曹泉
- Source temperature
- 49.6℃
- pH
- 7.3
- Flow rate
- 290 L/min
- Flow type
- 動力揚湯
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2020-05-27
- Analyst organization
- 一般財団法人北海道薬剤師会公衆衛生検査センター
- Registration No.
- 北海道第2号
Cations
- Sodium ion Na⁺
- 250 mg/kg
- Potassium ion K⁺
- 51.3 mg/kg
- Ammonium ion NH₄⁺
- 0.30 mg/kg
- Magnesium ion Mg²⁺
- 15.3 mg/kg
- Calcium ion Ca²⁺
- 24.1 mg/kg
- Aluminum ion Al³⁺
- not detected
- Manganese ion Mn²⁺
- 0.10 mg/kg
- Iron(II) ion Fe²⁺
- 0.00 mg/kg
- Iron(III) ion Fe³⁺
- 0.30 mg/kg
- Zinc ion Zn²⁺
- not detected
- Lead ion Pb²⁺
- not detected
- Copper ion Cu²⁺
- not detected
- Cadmium ion Cd²⁺
- not detected
- Total cations
- 0.34 mg/kg
Anions
- Fluoride ion F⁻
- 0.40 mg/kg
- Chloride ion Cl⁻
- 170 mg/kg
- Hydrogen sulfide ion HS⁻
- 0.00 mg/kg
- Thiosulfate ion S₂O₃²⁻
- 0.00 mg/kg
- Sulfate ion SO₄²⁻
- 141 mg/kg
- Bicarbonate ion HCO₃⁻
- 446 mg/kg
- Carbonate ion CO₃²⁻
- 0.70 mg/kg
- Hydrogen phosphate HPO₄²⁻
- 0.20 mg/kg
- Total anions
- 0.76 mg/kg
Undissociated Components
- Metasilicic acid H₂SiO₃
- 176 mg/kg
- Metaboric acid HBO₂
- 6.0 mg/kg
- Total undissociated
- 0.18 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 37.8 mg/kg
- Free hydrogen sulfide H₂S
- 0.00 mg/kg
- Total dissolved gas
- 0.04 mg/kg
Totals
- Total dissolved substances
- 1.3 mg/kg
- Component total
- 1.3 mg/kg
- Evaporation residue
- 0.97 mg/kg
Usage
- Heating
- No
- Dilution
- No
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
Indications & Contraindications
- Bathing indications
- Cuts and grazes, Peripheral circulatory failure, Poor circulation, Xeroderma, Depression
- General indications
- High blood pressure (mild), Rheumatoid arthritis, Autonomic instability, Insomnia, Chronic pain or stiffness in muscles and joints, Muscle stiffness due to motor paralysis, Gastrointestinal dysfunction
- Contraindications
- Acute illness (especially with fever), Active tuberculosis, Malignant tumors, Severe heart disease, Respiratory failure, Renal failure, Bleeding disorders, Severe anemia, Any actively progressing illness, Pregnancy (especially early and late stages)
Drinking
- Drinkability
- Not drinkable
