Disease prevention through proper hygiene is critical in disasters. Learn water needs beyond drinking, improvised sanitation, and hygiene practices that prevent outbreak.
In a disaster, most people focus on drinking water — and rightly so. But the diseases that kill most people in displacement and infrastructure failure are spread through hands, waste, and contaminated surfaces, not primarily through drinking water. Cholera, typhoid, hepatitis A, dysentery, and many other illnesses are preventable with basic hygiene. This guide explains how to manage water for sanitation and hygiene when supplies are limited.
⚠️ Diarrhoeal diseases kill approximately 2,200 children per day globally — the vast majority from preventable sanitation failures. In a disaster that degrades sanitation infrastructure, hand hygiene becomes the single most important health intervention available to you.
Many preparedness guides state the minimum drinking water requirement of 2–3 litres per person per day. This is the absolute survival floor. A full picture of water needs is much higher.
| Use | Minimum per Person/Day | Comfortable per Person/Day |
|---|---|---|
| Drinking | 2–3 litres | 2–3 litres |
| Basic food preparation | 1–2 litres | 2 litres |
| Basic hand washing (6x/day) | 1–2 litres | 2–3 litres |
| Basic facial washing | 0.5 litres | 1 litre |
| Oral hygiene | 0.2 litres | 0.5 litres |
| Sponge bathing (2–3x/week) | 2–4 litres per bath | 5–10 litres per bath |
| Toilet flushing (if available) | 6–10 litres per flush | — |
| Laundry (minimal) | 2–4 litres per session | — |
| Total minimum | ~7–12 litres/day | ~50 litres/day (WHO standard) |
The WHO standard for a dignified quality of life is 50 litres per person per day. In an acute emergency, 7–15 litres per day is the practical minimum that maintains health while conserving supply.
Handwashing with soap prevents approximately 30–48% of diarrhoeal illness and 16–23% of respiratory infections. It is the most cost-effective public health intervention known.
Alcohol-based hand sanitiser (minimum 60% alcohol concentration) is effective against most bacteria and viruses, but NOT against norovirus, Clostridioides difficile, or when hands are visibly soiled.
Soap and minimal water: A 500ml bottle of water poured slowly over soapy hands is sufficient for effective handwashing.
Ash or sand (improvised): In extreme scenarios with no soap, rubbing hands with dry wood ash or fine sand followed by rinse water provides some mechanical removal of contamination. This is a last resort only.
When running water is unavailable:
Tippy tap (basic):
Gravity drip station:
Full bathing without running water is achievable with 2–4 litres of water.
Frequency: In a short emergency (under 7 days), every 2–3 days is sufficient for most people. In extended scenarios, daily attention to high-risk areas (armpits, groin, feet) prevents skin infections that can become serious.
When flushing toilets are unavailable, human waste management becomes a critical public health issue.
For scenarios lasting weeks or longer:
⚠️ Never dispose of human waste near water sources, wells, or low ground that drains to water. Contamination of drinking water with faecal matter is the mechanism of cholera and typhoid — both of which spread explosively in disaster conditions.
Grey water is water that has been used for washing (not toilet use). In a water-scarce emergency, it can be reused for:
Grey water should NOT be reused for:
Menstrual hygiene management is often overlooked in preparedness guides. Inadequate management leads to infection, social distress, and physical complications.
Emergency menstrual kit should include:
In extended emergencies: A menstrual cup used with basic hygiene reduces water, waste disposal, and supply requirements dramatically. Include one per person of reproductive age in your emergency supplies.
Oral health deteriorates rapidly under stress and with dietary changes. Tooth infections and abscesses, if untreated, can become life-threatening.
Minimum oral hygiene protocol:
If no toothbrush: A clean cloth wrapped around the finger and rubbed across teeth provides basic mechanical cleaning.
Infants in disaster conditions face heightened infection risk.
| Situation | Action |
|---|---|
| Limited water — what to prioritise | Drinking first, then handwashing, then food prep, then bathing |
| No running water | Set up tippy tap or gravity drip for handwashing station |
| Toilet unavailable | Use bucket with liner and dry cover material; site away from water |
| Hands visibly dirty, no water | Use soil or ash as mechanical cleaner; sanitiser alone insufficient |
| Menstrual supply running low | Shift to reusable cloth pads or menstrual cup to extend supply |
| Infant formula preparation with questionable water | Boil and cool water before mixing; never use untreated water for infants |
| Grey water available | Use for toilet flushing and plant watering only — not food or drinking |
| Outbreak of diarrhoea in group | Intensify hand hygiene immediately; isolate waste; boil all drinking water |
| Skin breakdown in nappy area | Apply barrier cream; increase change frequency; allow air exposure |
| Oral health deteriorating | Maintain twice-daily brushing even with minimal water |
// Sources
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