Noboribetsu Onsen
ホテルまほろば
Hokkaido Noboribetsu
北海道 登別市

Noboribetsu Onsen Gensen 24-go-sen

Analysis Verified
登別温泉 24号泉
Strong Acidic Iron(II) Spring

Noboribetsu Onsen stands as Hokkaido's premier thermal destination, its rugged Jigokudani (Hell Valley) landscape drawing visitors for centuries seeking authentic therapeutic bathing. This powerfully acidic spring, enriched with iron and therapeutic minerals, beckons those managing chronic skin conditions and persistent fatigue who crave an immersive healing retreat.

AI Generated
SPRING TYPE
Acidic Spring

These springs have a strong antibacterial effect which can result in a mild tingling sensation on contact. Effective for healing wounds and relieving inflammatory skin conditions. Those with sensitive skin should rinse with fresh water after bathing.

See features & indications
Bathing indications
Atopic dermatitisPlaque psoriasisEpidermal suppurationImpaired glucose tolerance (diabetes)
Cautions
  • 皮膚または粘膜の敏感な方、高齢者の皮膚乾燥症の方は禁忌です。
  • 肌が弱い方は入浴後に真湯で洗い流してください。
Definition :Contains 1 mg/kg or more of hydrogen ions.
Source: 環境省「あんしん・あんぜんな温泉利用のいろは」(監修:日本温泉気候物理医学会)Read full article
PH VALUE
2.0
Strongly Acidic
Acidic ← 07 Neutral14 → Alkaline
Strongest class of acidic springs. Very strong antibacterial and skin-softening effects. Kusatsu Onsen (pH 1-2) is a representative example.
Caution: Avoid prolonged bathing. Rinse with fresh water or weakly alkaline water after bathing. Those with sensitive skin or mucous membranes should refrain from bathing.
TEMPERATURE
95.5
Very Hot Spring
Near boiling, extremely hot. Requires substantial cooling or dilution.
KEY MINERALS

The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).

Metaboric acidSee detail
303 mg/kg

Undissociated boric acid with antibacterial action that keeps the skin surface clean.

Aluminum ion
36.0 mg/kg

Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.

Metasilicic acidSee detail
488 mg/kg

A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.

Chloride ionSee detail
2782 mg/kg

Boosts after-bath warmth and warms the body from the core.

Sodium ionSee detail
1394 mg/kg

Gentle warming effect that helps you stay warm after bathing.

CHARACTER · COMPOSITION PROFILE
1234StimulationBactericidalSkin BeautyHeat RetentionRelaxation

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.

USAGE
HeatedNo
DilutedYes
RecycledYes
FilteredNo
DisinfectedYes
AdditivesNo

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.

SENSORY TEST
Color
無色澄明
Smell
無臭
Taste
弱酸味
BATHING TIPS
AI Generated

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.

EFFECT STORY
AI Generated

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.

CAUTIONS
AI Generated

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
登別温泉 24号泉
Spring type
酸性含鉄(II)-ナトリウム-塩化物温泉(酸性低張性高温泉)
Source temperature
95.5℃
pH
1.97
Flow rate
105 L/min
Flow type
自然湧出
Osmotic pressure
低張性

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
2.0 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
3.8 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
0.80 mg/kg

Dissolved Gas

Free carbon dioxide CO₂
0.00 mg/kg
Free hydrogen sulfide H₂S
0.40 mg/kg
Total dissolved gas
0.00 mg/kg

Totals

Total dissolved substances
6.5 mg/kg
Component total
6.5 mg/kg
Evaporation residue
6.3 mg/kg

Usage

Heating
No
Dilution
Yes
Recycle / Filter
Recycled
Additives
No
Disinfection
Yes

Drinking

Drinkability
Not drinkable

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The descriptions, catch phrases, and translations on this page are generated by AI (Claude). pH, temperature, and component values are OCR-extracted from the official analysis report. Learn more