Owakudani Onsen Steam-induced Mixed Spring
Analysis VerifiedOriginating from the fumaroles of Owakudani, born from the eruption of Hakone volcano approximately 3,000 years ago, this artificially developed hot spring began to be supplied to Sengokuhara and Gora by Hakone Onsen Kyokyu Co., Ltd. in Showa 5 (1930). Its renowned milky white waters, blended with naturally gushing spring water, offer a pleasant sensation that tightens the skin and a powerful restorative warmth that penetrates deep into the body's core. After bathing, you'll feel surprisingly refreshed and light. It's a perfect companion when you seek to feel the Earth's energy and achieve deep relaxation and rejuvenation for your mind and body.
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.
The aroma typical of sulfur springs, with circulatory and antibacterial effects.
- Acidic (pH)pH 2.1
- 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.
- Chloride (salt)342 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.
- Sulfate443 mg/kg
- Feel
- Your skin feels moist; the water may taste slightly bitter.
- Said to
- Said to retain heat well and help heal cuts. Bathing indications include cuts and dry skin.
- Note
- It warms you well—do not stay in too long.
- Metasilicic acid157 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 temperature60.6℃
- 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 very strong acidity of pH 2.1, those with sensitive skin should be cautious. To prevent overheating, avoid long soaks and it is recommended to rinse off the spring water with a shower after bathing. Be careful not to get it in your eyes.
This potent acidic spring, with a pH of 2.1, has long been used for balneotherapy. Its sterilizing properties are associated with improving skin issues, traditionally seen as a way to support immune system stimulation. As a sulfate spring, it may also help relieve pain from cuts and joints. The high metasilicic acid content of 157 mg/kg is also said to promote skin metabolism.
Due to its very high acidity, individuals with sensitive skin or mucous membranes should bathe with caution. It can cause strong irritation if it gets in your eyes. Please refrain from bathing if you have general contraindications such as acute illness or severe heart disease.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Owakudani Onsen Steam-induced Mixed Spring
- Spring type
- Acidic Calcium Sulfate and Chloride Hot Spring
- Old spring type name
- 酸性－含塩化土類－石膏泉
- Source temperature
- 60.6℃
- pH
- 2.1
- Flow type
- 造成温泉（蒸気造成混合泉）
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2018-09-28
- Analyst organization
- 神奈川県温泉地学研究所
- Registration No.
- 神奈川県知事登録第1号
Cations
- Hydrogen ion H⁺
- 8.0 mg/kg
- Lithium ion Li⁺
- 0.00 mg/kg
- Sodium ion Na⁺
- 40.5 mg/kg
- Potassium ion K⁺
- 3.2 mg/kg
- Ammonium ion NH₄⁺
- 0.22 mg/kg
- Magnesium ion Mg²⁺
- 34.7 mg/kg
- Calcium ion Ca²⁺
- 90.6 mg/kg
- Aluminum ion Al³⁺
- 7.5 mg/kg
- Manganese ion Mn²⁺
- 1.3 mg/kg
- Iron(II) ion Fe²⁺
- 13.2 mg/kg
- Zinc ion Zn²⁺
- 0.04 mg/kg
- Lead ion Pb²⁺
- 0.02 mg/kg
- Strontium ion Sr²⁺
- 0.17 mg/kg
- Copper ion Cu²⁺
- 0.00 mg/kg
- Cadmium ion Cd²⁺
- 0.00 mg/kg
- Total cations
- 199 mg/kg
Anions
- Fluoride ion F⁻
- 0.80 mg/kg
- Chloride ion Cl⁻
- 342 mg/kg
- Sulfate ion SO₄²⁻
- 443 mg/kg
- Bromide ion Br⁻
- 0.14 mg/kg
- Hydrogen sulfate HSO₄⁻
- 118 mg/kg
- Nitrate ion NO₃⁻
- 0.49 mg/kg
- Total anions
- 904 mg/kg
Undissociated Components
- Sulfuric acid H₂SO₄
- 2.4 mg/kg
- Metasilicic acid H₂SiO₃
- 157 mg/kg
- Metaboric acid HBO₂
- 14.2 mg/kg
- Total undissociated
- 175 mg/kg
Dissolved Gas
- Free hydrogen sulfide H₂S
- 1.3 mg/kg
Totals
- Component total
- 1278 mg/kg
- Evaporation residue
- 1236 mg/kg
Usage
- Heating
- No
- Dilution
- No
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
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
