Total time: 20 seconds minimum (most people: 6 seconds)

Steps:
  1. Wet hands with clean water
  2. Apply soap (liquid or bar — no difference in effectiveness)
  3. Lather ALL surfaces:
     - Palms
     - Back of hands
     - Between fingers
     - Fingertips and nails (most missed area)
     - Thumbs (most missed joint)
     - Wrists
  4. Scrub for 20 seconds (hum "Happy Birthday" twice)
  5. Rinse thoroughly under running water
  6. Dry with clean towel or air dry
     (Wet hands spread 1000× more bacteria than dry hands)

When you MUST wash hands:
  Before: Cooking, eating, touching your face, treating wounds
  After:  Toilet, changing diapers, handling raw meat/fish/eggs,
          touching animals, blowing nose, coughing, sneezing,
          touching garbage, handling money, public transport

Brushing (twice daily, non-negotiable):
  Morning: Before breakfast, not after (acid from food weakens enamel)
  Night: Most important — bacteria multiply overnight
  
  Technique (most people do this wrong):
  → 45-degree angle to gum line
  → Small circular motions or gentle horizontal strokes
  → 2 minutes (set a timer — most people do 30-45 seconds)
  → Cover: outer surface, inner surface, chewing surface
  → Brush tongue (major source of bad breath bacteria)
  
  Use: Soft-bristled brush (medium/hard damages gums and enamel)
  Replace: Every 3-4 months or after illness
  
Fluoride toothpaste: Yes, it works, it is safe
  Cavity protection is well-established
  Fluorosis only from excess fluoride in water, not toothpaste

Flossing (or water flosser / interdental brushes):
  40% of tooth surfaces are between teeth where brush can't reach
  Floss BEFORE brushing (brush cleans what you loosen)
  Once daily, before bed
  Water flosser (Waterpik): Excellent alternative, easier technique

Tongue scraping:
  Significant source of VSCs (volatile sulfur compounds = bad breath)
  Use dedicated tongue scraper or spoon, scrape back to front
  Clean with running water, repeat 5-7 times

Mouthwash (optional, NOT a replacement):
  Alcohol-free formulations preferred (alcohol mouthwash dries mouth)
  Chlorhexidine: Prescription, powerful but stains teeth with long use
  Fluoride mouthwash: Good addition for cavity-prone individuals
  
Dentist visits:
  Every 6 months for cleaning (even with perfect home care)
  Professional cleaning removes calculus/tartar that brushing can't
  Most dental problems are asymptomatic until severe

"Brush harder for cleaner teeth" → WRONG
  Hard brushing damages enamel irreversibly and causes gum recession
  Gentle pressure, correct technique, full coverage
  
"Sugar-free food is fine for teeth" → PARTIALLY WRONG
  Acidic foods (citric acid, phosphoric acid in diet drinks) erode enamel
  Frequency matters more than amount — constant sipping of any acidic drink is worse

"Whitening toothpastes are safe" → MOSTLY RIGHT with caveats
  Abrasive whitening toothpastes can damage enamel if used daily long-term
  Peroxide-based whitening: safe, limited teeth whitening
  Best whitening: Professional tray with carbamide peroxide

Ideal shower:
  → Temperature: Warm, not hot (hot strips natural oils, disrupts skin barrier)
  → Duration: 5-10 minutes (longer dries skin)
  → Frequency: Daily for most people in tropical climates
  
What to wash with soap vs water only:
  Use soap: Armpits, groin, feet, face (with appropriate face wash)
  Water only is sufficient: Arms, legs, torso, back (unless sweaty)
  Over-soaping disrupts skin microbiome and pH

Skin microbiome:
  Your skin has 1,000+ species of bacteria and fungi living on it
  These protect against pathogens, regulate inflammation, produce vitamins
  Antibacterial soaps and over-washing harm these communities
  Use plain soap, not "antibacterial" variants for daily use

Moisturising:
  Apply within 3 minutes of shower (lock moisture in before evaporation)
  Dry skin leads to cracking → entry point for pathogens
  In Indian climate: lightweight oils (almond, coconut) or simple moisturiser

Washing frequency (varies by hair type):
  Oily hair/scalp: Every 2-3 days
  Normal: 2-3 times per week
  Dry/curly/coily: 1-2 times per week
  
Scalp health:
  Dandruff (seborrheic dermatitis): Caused by Malassezia yeast overgrowth
    → Ketoconazole or selenium sulfide shampoo (weekly)
  
Post-wash:
  Pat dry, don't rub vigorously (damages hair shaft)
  Detangle when wet with wide-tooth comb from ends upward
  Air dry when possible — heat damages hair protein

Bacteria multiply rapidly between 4°C and 60°C
  Below 4°C: Growth slows dramatically (refrigerator)
  Above 60°C: Most bacteria killed (cooking/hot holding)
  Between 4-60°C: Danger zone — food must not sit here >2 hours

Food safety rules:
  → Cook chicken/meat to internal temperature 74°C+
  → Never thaw at room temperature — in refrigerator or cold water
  → Don't keep cooked food out for more than 2 hours
  → Never refrig hot food in sealed container (breeds bacteria)
    Cool food to room temperature first, then refrigerate
  → "Sniff test" does not detect dangerous bacteria
    Pathogenic bacteria often don't smell or look different

The biggest home kitchen risk:

Cutting boards:
  Separate boards for: raw meat, vegetables, cooked food
  Colour-coding helps (red = raw meat, green = vegetables)
  
Raw meat handling:
  Wash hands after touching raw meat, before touching anything else
  Don't rinse raw chicken (spreads bacteria to sink and surroundings)
  Cook thoroughly — kills any bacteria present
  
Refrigerator storage:
  Raw meat: Bottom shelf (can't drip onto other food)
  Ready-to-eat food: Top shelves
  
Sponge/dishcloth:
  Most bacteria-laden item in most kitchens
  Replace weekly or microwave wet sponge for 2 minutes daily
  Use fresh dishcloth, air dry completely between uses
  
Refrigerator temperature:
  Should be 1-4°C (most people set it warmer)
  Check with thermometer — don't rely on dial setting

Covering coughs and sneezes:
  Correct: Into elbow (not hand — hand then touches surfaces)
  
Face touching:
  Average person touches face 20-23 times per hour
  Most virus/bacteria entry: eyes, nose, mouth
  Hand hygiene before face touching is critical
  
Indoor air quality:
  Ventilation: Open windows when possible — indoor air often 2-5× more polluted than outdoor
  Air purifiers: HEPA filter removes particulate matter, viruses
  Plants: Some evidence for VOC removal (snake plant, pothos) but limited
  Humidity: 40-60% optimal — too dry dries out mucus membranes (defence)
  
Mask wearing:
  Well-fitted N95/KN95 provides strong protection from respiratory pathogens
  Cloth masks: Minimal protection for wearer, some source control
  When to wear: Crowded indoor spaces during respiratory illness seasons
                Especially around elderly/immunocompromised

Most contaminated surfaces (studies consistently find):
  1. Kitchen sponge/dishcloth (replace/sanitise weekly)
  2. Phone screen (90× more bacteria than toilet seat)
     Clean with 70% isopropyl alcohol wipe every few days
  3. Refrigerator handles
  4. Light switches and door handles
  5. Keyboard and mouse
  6. Remote controls
  7. Faucet handles

Cleaning products:
  All-purpose cleaner: Most bacteria/viruses (not spores)
  Bleach solution (1:50 dilution): Effective against almost all pathogens
    → Don't mix bleach with ammonia or acidic cleaners (toxic gas)
  Hydrogen peroxide: Good alternative to bleach
  
  Note: "Kills 99.9% of bacteria" on product label
    The 0.1% remaining can still reproduce back to full population quickly
    Frequency of cleaning matters as much as product strength

Tap water concerns in India:
  Chlorination kills most bacteria/viruses
  But old pipes → re-contamination possible
  Fluoride levels vary by region
  Heavy metals (lead, arsenic) in some areas
  
Water purification hierarchy (best to acceptable):
  1. RO + UV (removes all biological and chemical concerns)
     Best for areas with unknown water quality
  2. UV only (kills microbes, doesn't remove heavy metals or TDS)
  3. Boiling 5+ minutes (kills microbes, doesn't remove chemicals)
  4. Chlorination tablets (travel/emergency use)
  
RO wastewater:
  Typically 50-75% water wasted for every litre produced
  Collect and use for mopping, plants, toilet flushing

Typhoid (Salmonella typhi):
  Transmission: Contaminated food and water
  Prevention: Handwashing, safe water, not eating street food in high-risk areas
  Vaccine available (recommended)

Hepatitis A and E:
  Transmission: Contaminated water and food (especially undercooked shellfish)
  Prevention: Safe water, handwashing, vaccine (Hep A)
  
Diarrheal diseases (most common in India):
  ORS (Oral Rehydration Solution) is life-saving — know how to make it
  Recipe: 1 litre water + 6 tsp sugar + 1/2 tsp salt
  Don't stop eating — bland food (banana, rice, toast) helps recovery
  Seek medical care for: blood in stool, high fever, signs of severe dehydration

Dengue, Malaria (mosquito-borne):
  Prevention: Eliminate standing water around home (containers, tyres, water tanks)
  Use mosquito nets, repellents (DEET-based most effective)
  Wear full sleeves at dusk when mosquitoes are most active
  Early diagnosis critical — Dengue especially

COVID and respiratory viruses:
  Ventilation + hand hygiene + masking when appropriate
  Vaccination prevents severe illness for most people

Morning:
  ✓ Brush teeth (2 minutes, all surfaces)
  ✓ Tongue scraping
  ✓ Shower/wash
  ✓ Wash hands after toilet, before food preparation

During day:
  ✓ Hand hygiene before eating, after toilet, after public spaces
  ✓ Don't touch face with unwashed hands
  ✓ Phone screen cleaning 2-3× per week

Evening/Night:
  ✓ Brush teeth + floss (before bed — most important)
  ✓ Wash hands before and after food preparation
  ✓ Clean kitchen surfaces and handle area after cooking

Weekly:
  ✓ Replace/sanitise kitchen sponge
  ✓ Clean high-touch surfaces (handles, switches, remotes)
  ✓ Wash bedsheets (bacteria, dust mites accumulate rapidly)
  ✓ Clean bathroom thoroughly
  ✓ Check refrigerator for expired food