How to Read Your Lead Dust Test Results: The New EPA Rules Explained

If you live in a home built before 1978, you’ve likely heard about the dangers of lead paint. But did you know that the paint itself isn’t the only hazard? Over time, lead paint breaks down into an invisible, toxic dust that settles on floors, window sills, and toys.

If you recently tested your home using our In-Lab Lead Solids Test Kit, your lab report will show lead dust levels measured in a unit called µg/ft².

But what does that number actually mean for your family’s safety?

The EPA recently finalized new lead regulations. In this guide, we will break down the new standards, explain how to read your lab results, and show you exactly what to do next to keep your home safe.

What Does µg/ft² Mean?

Your lab report measures lead in micrograms per square foot, written as µg/ft².

• Microgram (µg/ft²): A microgram is incredibly small—it is one-millionth of a gram. To put that in perspective, a single grain of table salt weighs about 58 µg/ft²
• Square Foot (ft²): This is a 1 foot by 1 foot square area of your floor or window.

Because lead is highly toxic even in microscopic amounts, it only takes a tiny amount spread over a square foot to pose a serious health risk, especially to children.

The New EPA Standards: “Reportable” vs. “Action” Levels

The EPA recently changed how it defines lead hazards. Historically, the EPA used the same number for a “hazard” and a “safe cleanup level.” Today, they have changed these terms to reflect the new standard: there is no safe level of lead exposure.

The EPA now uses two distinct standards:

1. Dust-Lead Reportable Levels (The Hazard Standard): This is set at any detectable level analyzed by an EPA-recognized laboratory. If our lab detects any lead in your dust sample, the EPA considers it a hazard.
2. Dust-Lead Action Levels (The Post-Abatement Standards): If you hire professionals to remove lead paint from your home (called abatement), they must clean the home thoroughly. The home is only considered certified “clean” when lead levels fall below these strict action limits.

Lead Dust Standards at a Glance

The hazard level depends heavily on where in your home the dust sample was collected. Use this quick reference table to compare your lab results:

Window Sills vs. Window Troughs: What’s the Difference?

When testing windows, it is incredibly important to understand the difference between the sill and the trough, as they accumulate lead very differently.

• The Window Sill (or Stool): This is the flat, interior wooden ledge that sticks out into the room—the spot where you might place a houseplant or where a toddler might pull themselves up to look outside.
• The Window Trough (or Well): This is the hidden, U-shaped channel outside the inner window pane where the window frame slides down. If you have storm windows, the trough is the space between the inner window and the outer storm window.

Why are Window Troughs so dangerous?

Window troughs are the most common area to fail a lead dust test. When old wood-sash windows slide up and down, the friction acts like sandpaper, grinding lead paint into a fine, toxic powder. This powder falls directly into the window trough, where moisture, condensation, and weather make the paint peel and deteriorate even faster.

What Should You Do If Lead is Detected?

Your next steps depend on how high your numbers are.

Lead is detected, but below the Action Levels

(Floors are under 5 µg/ft², Sills are under 40 µg/ft²)

Even at low levels, you should take steps to minimize exposure. But you do not need a professional team:

• Don’t dry sweep or dust: This stirs the invisible lead particles into the air where they can be inhaled.
• Use a HEPA Vacuum: Standard household vacuums spit tiny lead dust particles back out into the room. Use a vacuum equipped with a true HEPA filter.
• Wet Clean Hard Surfaces: Frequently wipe down floors and windows with a damp cloth or microfiber mop using a general all-purpose cleaner. Throw away disposable wipes after use.

Lead levels are AT or ABOVE the Action Levels

(Floors are greater than 5 µg/ft² or Sills are greater than 40 µg/ft²)

This indicates a significant, active lead hazard in your home.

• Do not attempt to scrape or sand the paint yourself. DIY paint removal often makes lead dust hazards significantly worse.
• Hire an RRP-Certified Professional: Look for contractors certified under the EPA’s Lead Renovation, Repair, and Painting (RRP) program. They have the specialized containment tools and protective gear to safely seal or remove the lead source.

Lead Dust FAQ

Why is lead dust so dangerous for children?

Young children are at the highest risk because they spend time playing on the floor where lead dust settles, and they frequently put their hands and toys in their mouths. Even low levels of lead exposure can cause irreversible damage to a child’s brain development, resulting in learning disabilities, behavioral issues, and hearing problems.

How often should I test my home for lead dust?

If you live in a pre-1978 home with original windows and doors, we recommend testing your floors and window troughs at least once a year, or immediately if you notice paint cracking, peeling, or if you plan to do any home renovations.

Take Control of Your Home’s Safety Today

You can’t clean up a hazard you don’t know exists. By measuring the exact lead levels in your home with our In-Lab Lead Solids Test Kit, you get precise, lab-certified data and peace of mind.

Order Your Lead Dust Test Kit Today and protect your family from invisible lead hazards.