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Guide

What is a do-not-drink notice, and how is it different?

A do-not-drink notice means chemicals or toxins that boiling can't remove, and boiling can concentrate them. Drink and cook with bottled water (CDC, EPA).

Updated 2026-10-27· 11 official sources

Short answer. A do-not-drink notice means your tap water is, or could be, contaminated with chemicals or toxins, and boiling will not make it safe 1. With some contaminants it makes things worse: the EPA warns that boiling may increase cyanotoxin levels 3, and BC health officials say boiling can increase nitrate 5. Use bottled water for drinking, cooking, teeth, ice, formula and pets 1. Most still allow showering 36.

What are the three levels of water notice?

Water authorities use three levels, from least to most restrictive. The names vary by country, but the logic is the same.

Level Typical cause Boil the water? Drink or cook with tap water? Wash, shower, laundry?
Boil water Germs, or a treatment problem such as low chlorine 6 Yes, 1 minute at a rolling boil 6 Only after boiling 6 Yes, without swallowing the water 1
Do not drink / do not consume Chemicals or toxins 1, contaminants boiling can't remove 6 No: boiling will not make it safe 1 No, use bottled water 1 Usually yes 6, follow the notice 1
Do not use Any contact could be dangerous, including skin, lungs or eyes 1 No No No: bottled water for all purposes 1

In Canada, the middle level is usually called a "do not consume" advisory 611. In England, Thames Water used "do not drink" for the Bramley notice 9. The CDC notes that do-not-use advisories are rare 1.

Everything about the first level, boiling times, kettles and lifting, is in the Phaenyx guide on boil-water notices. This guide covers the two levels where boiling is the wrong reflex.

Why can boiling make contaminated water worse?

Boiling kills germs. It does not remove chemicals such as lead or nitrate 45, and for some contaminants it can raise the level in the water that is left 35.

  • Algal toxins (cyanotoxins). The EPA's model advisory reads: "Do not boil the tap water, as boiling water does not remove cyanotoxins and may increase toxin levels" 3.
  • Nitrate. HealthLink BC states that "boiling your water can increase the amount of nitrate in it" 5. Canada's maximum acceptable concentration is 45 mg/L, equal to 10 mg/L as nitrate-nitrogen 5.
  • Lead. The EPA states: "boiling water does not remove lead from water," and advises using only cold water for drinking, cooking and baby formula 4.
  • Fuel and hydrocarbons. In the 2024 Bramley incident in England, residents were told: "Don't use tap water even after boiling" 9.

The CDC sums it up: boiling water that contains harmful chemicals or toxins "will not make the water safe to use" 1. Home filters and pitchers are a separate question; the Phaenyx guide on emergency water filters covers what they can and cannot remove. Under a notice, the notice decides, not the filter.

What can you still do under a do-not-drink notice?

The CDC lists bottled water for drinking and cooking, brushing teeth, washing fruits and vegetables, preparing food, mixing baby formula, making ice and giving water to pets 1. Indigenous Services Canada lists similar uses to avoid under a do-not-consume advisory, and says tap water can still be used for handwashing, washing dishes, laundry and bathing 6.

The EPA's model cyanotoxin advisory is similar: "Everyone may use tap water for showering, bathing, washing hands, washing dishes, flushing toilets, cleaning and doing laundry" 3. The Bramley notice allowed washing, showering and flushing toilets 9.

These are typical rules, not universal ones. The CDC notes that each advisory may give its own instructions on food, ice, dishes, cleaning, brushing teeth, bathing and toilets 1. The wording on your notice overrides any general list, including this one.

What changes under a do-not-use notice?

Everything. The CDC says: "Do not drink or use tap water for any purpose as long as the advisory is in effect" 1. Canadian guidance says a do-not-use advisory is issued when the water poses a serious health risk 11 or when bathing could irritate the skin, eyes or nose, for example after a chemical spill 6.

Authorities can step down from one level to another as tests come back. In Corpus Christi, Texas, a "Do Not Use the Water" advisory was issued on 14 December 2016 after a suspected backflow of an emulsifier (Indulin AA-86 with hydrochloric acid) 10. The city was then split into three zones: the advisory was lifted in one, a second could resume bathing, showering, toilets and laundry but drink only bottled water, and the third stayed under the full advisory 10.

What about babies, children and pets?

Some limits are set lower for young children. The EPA's 10-day health advisory for microcystins is 0.3 µg/L for bottle-fed infants and pre-school children, against 1.6 µg/L for school-age children and adults 2. For cylindrospermopsin, the figures are 0.7 µg/L and 3.0 µg/L 2.

  • Formula: Use bottled water to mix formula under a do-not-drink advisory 1. For nitrate in well water, HealthLink BC says never to give a baby well water, or formula mixed with it, unless it has been tested safe for nitrate, and to boil water for formula no more than 2 minutes 5.
  • Bathing: Agencies differ. Indigenous Services Canada says infants and toddlers should be sponge bathed under a do-not-consume advisory 6. The EPA model advisory allows bathing but says children under six should be supervised to prevent swallowing 3. In Corpus Christi's partial zone, infants and young children were told not to bathe in tap water 10.
  • Pets: Give pets bottled water 1911.

If your child or anyone at home may have swallowed the water and feels unwell, or if you are pregnant, breastfeeding or caring for someone with a medical condition, call your doctor or local health line. The EPA model advisory lists upset stomach, vomiting and diarrhoea among possible effects of cyanotoxins and says to seek medical attention if family members are ill 3.

How long does a do-not-drink notice last?

It lasts until tests show the water is safe again, which can take days or months.

  • Toledo, Ohio, 2014: After a Lake Erie algal bloom, the mayor issued a "do not drink or boil" advisory on the morning of 2 August to nearly 500,000 customers 7. It was lifted on Monday 4 August, after treatment changes reduced toxin levels 7.
  • Iqaluit, Nunavut, 2021: A do-not-consume order issued by Nunavut's Department of Health ran from 12 October to 10 December 2021 8, close to two months.
  • Bramley, England, 2024: Thames Water's notice to 616 properties, issued on 30 May after elevated hydrocarbons were found and traced to a historical petrol station leak, came with letters and bottled water delivered door to door 9.

Because these notices can come without warning and last weeks, stored water matters more here than in a boil-water notice. The Phaenyx guide on how much water to store gives the quantities.

What official agencies recommend

  • United States (CDC): Do not drink means bottled water for drinking and cooking, and boiling will not help; do not use means bottled water for all purposes 1.
  • United States (EPA): For cyanotoxins, do not drink and do not boil; showering, washing and laundry allowed, with children under six supervised 3. Boiling does not remove lead 4.
  • Canada (Indigenous Services Canada, Nunavut): Do not consume when contaminants can't be removed by boiling; bathing allowed, with sponge baths for infants and toddlers 6 or children 11. Do not use: no use for any purpose 6.
  • Canada (HealthLink BC): Boiling can increase nitrate; limit 45 mg/L 5.
  • England (Thames Water, via Waverley Borough Council): No drinking, cooking, teeth or pets even after boiling; washing and toilets allowed 9.

Where agencies differ, mainly on bathing young children, follow the notice from your own water supplier or health authority.

Frequently asked questions

Can I boil the water to make it safe under a do-not-drink notice?

No. The CDC says boiling water with harmful chemicals or toxins will not make it safe 1, and the EPA says boiling may increase cyanotoxin levels 3. Use bottled or supplied water.

Can I shower during a do-not-drink notice?

Usually yes, if the notice allows it. The EPA model advisory and Canadian guidance both allow showering and bathing 36, but not under a do-not-use advisory 1. Keep water out of your mouth and supervise young children 3.

Can my dog or cat drink the tap water?

No. The CDC lists giving water to pets among the uses that need bottled water 1, and the Bramley notice said the same 9.

What is the difference between "do not consume" and "do not drink"?

They are two names for the same level: Indigenous Services Canada says do-not-consume advisories are also called do-not-drink advisories 6. Canadian authorities use "do not consume" for contaminants boiling can't remove 611; the CDC uses "do not drink" for chemicals or toxins 1.

Next step: your plan

See the drinking-water risks where you live, country by country. Your Phaenyx plan's "Water and air" section sets out the water and air risks for your postal code, and the Phaenyx Safe app keeps the reflex cards for all three notice levels offline, so you know whether to boil or not before you reach for the kettle. Build your Phaenyx plan.

Sources

  1. Centers for Disease Control and Prevention (CDC) — Drinking Water Advisories: An Overview — https://www.cdc.gov/water-emergency/about/drinking-water-advisories-an-overview.html (accessed 2026-10-27)
  2. U.S. Environmental Protection Agency (EPA) — EPA Drinking Water Health Advisories for Cyanotoxins — https://www.epa.gov/habs/epa-drinking-water-health-advisories-cyanotoxins (accessed 2026-10-27)
  3. U.S. Environmental Protection Agency (EPA) — Press release template: Drinking Water Advisory – Everyone (cyanotoxin Do Not Drink advisory) — https://www.epa.gov/sites/default/files/2017-06/006_press_release-_everyone.docx (accessed 2026-10-27)
  4. U.S. Environmental Protection Agency (EPA) — Basic Information about Lead in Drinking Water — https://www.epa.gov/ground-water-and-drinking-water/basic-information-about-lead-drinking-water (accessed 2026-10-27)
  5. HealthLink BC — Nitrate in well water — https://www.healthlinkbc.ca/healthlinkbc-files/nitrate-well-water (accessed 2026-10-27)
  6. Indigenous Services Canada — About drinking water advisories — https://www.sac-isc.gc.ca/eng/1538160229321 (accessed 2026-10-27)
  7. U.S. Environmental Protection Agency (EPA) — Testimony of Peter C. Grevatt on cyanobacterial harmful algal blooms and drinking water, 19 November 2014 — https://www.epa.gov/sites/default/files/2015-08/documents/2014_11.19_hec_hearing_cyanotoxins_drinking_water_pgrevatt.pdf (accessed 2026-10-27)
  8. City of Iqaluit — Do Not Consume Order Lifted — https://iqaluit.ca/node/9831 (accessed 2026-10-27)
  9. Waverley Borough Council — Thames Water issues do not drink tap water notice to 616 Bramley properties, GU5 Surrey — https://www.waverley.gov.uk/Council-updates/Read-our-latest-news/thames-water-issues-do-not-drink-tap-water-notice-to-616-bramley-properties-gu5-surrey (accessed 2026-10-27)
  10. Texas Commission on Environmental Quality (TCEQ) — Corpus Christi Water Update #3 — https://www.tceq.texas.gov/assets/public/response/corpus-christi-water-update-3.pdf (accessed 2026-10-27)
  11. Government of Nunavut, Department of Health — Factsheet – Water Advisories — https://www.gov.nu.ca/sites/default/files/documents/2026-03/Factsheet_-_Water_Advisories_ENG.pdf (accessed 2026-10-27)

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Sources

  1. Centers for Disease Control and Prevention (CDC) · Drinking Water Advisories: An Overview checked 2026-10-27
  2. U.S. Environmental Protection Agency (EPA) · EPA Drinking Water Health Advisories for Cyanotoxins checked 2026-10-27
  3. U.S. Environmental Protection Agency (EPA) · Press release template: Drinking Water Advisory – Everyone (cyanotoxin Do Not Drink advisory) checked 2026-10-27
  4. U.S. Environmental Protection Agency (EPA) · Basic Information about Lead in Drinking Water checked 2026-10-27
  5. HealthLink BC (Government of British Columbia, Canada) · Nitrate in well water checked 2026-10-27
  6. Indigenous Services Canada (Government of Canada) · About drinking water advisories checked 2026-10-27
  7. U.S. Environmental Protection Agency (EPA) · Testimony of Peter C. Grevatt on cyanobacterial harmful algal blooms and drinking water, 19 November 2014 checked 2026-10-27
  8. City of Iqaluit (Nunavut, Canada) · Do Not Consume Order Lifted checked 2026-10-27
  9. Waverley Borough Council (England) · Thames Water issues do not drink tap water notice to 616 Bramley properties, GU5 Surrey checked 2026-10-27
  10. Texas Commission on Environmental Quality (TCEQ) · Corpus Christi Water Update #3 checked 2026-10-27
  11. Government of Nunavut, Department of Health (Canada) · Factsheet – Water Advisories checked 2026-10-27

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