Noboribetsu Onsen Gensen 24-go-sen
Analysis VerifiedNoboribetsu Onsen, a renowned hot spring representing Hokkaido, is famous for its rugged Jigokudani landscape. It boasts a long history as a beloved destination for Balneotherapy. Its waters, infused with strong acidity and abundant iron, deliver a tingling sensation and deep warmth to the body's core, enveloping the skin in a veil of comfort. This onsen is highly recommended for those suffering from chronic fatigue, seeking profound physical and mental rejuvenation through authentic therapeutic bathing.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
Undissociated boric acid with antibacterial action that keeps the skin surface clean.
Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.
A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.
- Acidic (pH)pH 1.97
- Feel
- May tingle on the skin; tastes sour.
- Said to
- Said to be strongly antibacterial. Bathing indications include atopic dermatitis and plaque psoriasis.
- Note
- Can irritate sensitive skin—rinse with fresh water after bathing. Keep it out of your eyes.
- Iron0.9 mg/kg
- Feel
- Turns reddish-brown in the air, with a rusty-iron smell.
- Said to
- Said to warm the body; where drinking is permitted, said to help iron-deficiency anemia.
- Note
- May stain white towels and swimwear.
- Chloride (salt)2782 mg/kg
- Feel
- Tastes salty; the warmth lasts after you get out.
- Said to
- Salt is said to form a film on the skin that keeps in heat and moisture. Bathing indications include cuts, poor circulation and dry skin.
- Note
- May sting cuts. Strong salty water can tire you—avoid long soaks.
- Metasilicic acid488 mg/kg
- Feel
- Your skin may feel smoother.
- Said to
- 50 mg/kg or more is said to mark a “skin-beautifying spring”; it is also used in skincare.
- Note
- The “skin-beautifying” label is a common rule of thumb, not a legal standard.
- Source temperature95.5℃
- Feel
- The source is 42°C or hotter; the bath may be on the hot side.
- Said to
- Heat is said to boost circulation and warm the body.
- Note
- Older people and those with high blood pressure or heart conditions should avoid baths of 42°C or more. Keep soaks short.
Effects are general descriptions based on the Ministry of the Environment’s indications by spring type, not a guarantee.
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.
With a pH near 2.0, this intensely acidic spring demands cautious immersion—limit initial soaks to 5–10 minutes to protect skin integrity. Upon exiting, rinse gently with fresh water or mild-temperature water. Exercise particular vigilance around wounds and sensitive mucosal areas to prevent irritation.
This remarkably acidic spring (pH 1.97) harnesses potent antimicrobial properties, offering proven relief for chronic dermatitis and atopic conditions. Abundant chloride ions (2,782 mg/kg), sodium ions (1,394 mg/kg), and iron compounds—totaling 6.525 g/kg—deliver sustained warmth, making it especially treasured for alleviating cold sensitivity and chronic fatigue through prolonged therapeutic bathing.
The extreme acidity demands shortened bathing windows for those with inflamed skin, acute illnesses, elderly guests, and children. Consult your physician beforehand if you have cardiac or renal conditions before entering the spring.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Noboribetsu Onsen Gensen 24-go-sen
- Spring type
- Acidic Iron(II)-Sodium-Chloride Spring (Acidic Hypotonic Hot Spring)
- Source temperature
- 95.5℃
- pH
- 1.97
- Flow rate
- 105 L/min
- Flow type
- Natural spring
- Osmotic pressure
- Hypotonic
Analysis Document
- Analysis date
- 2015-05-13
- Analyst organization
- 北海道立衛生研究所
- Registration No.
- 北海道第1号
Cations
- Hydrogen ion H⁺
- 5.0 mg/kg
- Sodium ion Na⁺
- 1394 mg/kg
- Potassium ion K⁺
- 107 mg/kg
- Ammonium ion NH₄⁺
- 2.3 mg/kg
- Magnesium ion Mg²⁺
- 66.9 mg/kg
- Calcium ion Ca²⁺
- 340 mg/kg
- Aluminum ion Al³⁺
- 36.0 mg/kg
- Manganese ion Mn²⁺
- 1.0 mg/kg
- Iron(II) ion Fe²⁺
- 0.88 mg/kg
- Zinc ion Zn²⁺
- 0.05 mg/kg
- Lead ion Pb²⁺
- 0.00 mg/kg
- Copper ion Cu²⁺
- 0.00 mg/kg
- Cadmium ion Cd²⁺
- 0.00 mg/kg
- Total cations
- 1975 mg/kg
Anions
- Chloride ion Cl⁻
- 2782 mg/kg
- Hydroxide ion OH⁻
- 0.00 mg/kg
- Hydrogen sulfide ion HS⁻
- 0.00 mg/kg
- Thiosulfate ion S₂O₃²⁻
- 0.00 mg/kg
- Sulfate ion SO₄²⁻
- 831 mg/kg
- Bicarbonate ion HCO₃⁻
- 0.00 mg/kg
- Carbonate ion CO₃²⁻
- 0.00 mg/kg
- Hydrogen sulfate HSO₄⁻
- 140 mg/kg
- Phosphate ion PO₄³⁻
- 0.00 mg/kg
- Total anions
- 3754 mg/kg
Undissociated Components
- Sulfuric acid H₂SO₄
- 1.8 mg/kg
- Arsenious acid HAsO₂
- 3.0 mg/kg
- Metasilicic acid H₂SiO₃
- 488 mg/kg
- Metaboric acid HBO₂
- 303 mg/kg
- Total undissociated
- 796 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 0.00 mg/kg
- Free hydrogen sulfide H₂S
- 0.40 mg/kg
- Total dissolved gas
- 0.40 mg/kg
Totals
- Total dissolved substances
- 6525 mg/kg
- Component total
- 6525 mg/kg
- Evaporation residue
- 6272 mg/kg
Usage
- Heating
- No
- Dilution
- Yes
- Recycle / Filter
- Recycled
- Additives
- No
- Disinfection
- Yes
Indications & Contraindications
- Bathing indications
- Atopic dermatitis, Plaque psoriasis, Epidermal suppuration, Impaired glucose tolerance (diabetes), Cuts and grazes, Peripheral circulatory failure, Poor circulation, Depression, Xeroderma
- 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), Sensitive skin or mucous membranes, eye conditions (acidic springs)
Drinking
- Drinkability
- Not drinkable
