Before you bring a baby home: a radon-first home safety checklist

Why radon first

Most of the things on a newborn safety list are things you can fix in an afternoon. Radon is the one with a clock on it: the test takes at least three months, and the fix comes after that. It’s also the one with no warning. A baby is small, breathes fast and spends many hours in one room, and the cell damage radon does isn’t repaired later, so the lowest-cost time to deal with it is before the baby comes home. What’s known about radon risk at young ages, and why the damage can’t be undone.

Plan backwards from the due date

The early reading is a screening tool. Health Canada bases decisions on a test of at least 91 days. A result far above or below 200 Bq/m³ usually holds up, and one near 200 doesn’t. How the 2-week reading works.

Radon checklist

Tick these off. They’re listed in the order to do them.

• Decide where the baby will sleep and spend timeThe nursery, and any playroom or basement space they’ll use more than four hours a day.
• Start a long-term radon test of at least 91 daysPlace the detector on the lowest level the baby will use, away from drafts, vents and exterior walls. Certified placement matters.
• Ask for an early reading at 14 days if the due date is under four months awayA calibrated professional monitor next to the detector.
• If the long-term average is over 200 Bq/m³, book mitigation before the baby comes homeMost installs are one day. Over 600 Bq/m³, Health Canada’s timeline is within one year, so do it before the baby arrives.
• If you’re between 100 and 200 Bq/m³, consider mitigating anywayBelow Canada’s guideline, above the World Health Organization’s 100. No safe threshold is known, and a baby has the longest time ahead.
• Keep the nursery off the basement level until a high result is fixedRadon is usually highest on the lowest floor. Upper floors are often lower, but not radon-free.
• Confirm the fix with a follow-up testA short check after the system has run for at least a day, then a long-term test during the heating season.
• If you’re moving in, ask for existing results and mitigation records, and test againA new home built under the 2024 Ontario Building Code has a rough-in, not a working system. It still needs testing. Details.
• If you have a radon system, check the manometerLevel fluid in the U-tube means the fan may have stopped.
• Keep the home smoke-freeSmoke and radon damage the same lung tissue. Health Canada also advises a smoke-free environment for a baby’s sleep.

The rest of the home

These are shorter, and cover what a newborn needs from the home on day one.

• Carbon monoxide alarms on every storey and near sleeping areasSince January 1, 2026, Ontario homes with a fuel-burning appliance, fireplace or attached garage need one on every storey, as well as next to sleeping areas. Check the dates and replace expired units.
• Working smoke alarms on every level and outside sleeping areasTest them.
• A safe sleep space: a crib, cradle or bassinet that meets Canadian safety regulationsFirm, flat mattress with no gaps at the sides, and no pillows, blankets, bumpers or toys. Babies sleep on their backs for every sleep.
• Room-share for the first six months, and check the radon level in that bedroomHealth Canada recommends the crib or bassinet in the parents’ room for the first six months, so your bedroom is where the baby will spend the night. If it’s in the basement, the test result matters even more.
• Check second-hand cribs and gear for recallsSearch Health Canada’s recalls database for the model before you use it.
• Keep the crib clear of windows, blind cords and outlets
• Set the tap water to 49 °C or lowerHealth Canada’s guidance is to keep the water heater at 60 °C to control Legionella bacteria and use an anti-scald valve to hold taps at 49 °C. Test bath water with your wrist or elbow, and stay within arm’s reach.

This is a home safety checklist, not medical advice. Your midwife, doctor or public health nurse can add to it for your family.

Common questions