What Happened?
Two companies, Lumetallix and Fluoro-Spec, are promoting the use of innovative, low-cost, easy-to-use test kits to quickly detect lead in the field at extremely low levels by forming lead halide perovskites (pronounced “pe-rov-skite”) that glow green under ultraviolet (UV) light.In this blog, Unleaded Kids shares our assessment of the test kits and the technology’s uses. To avoid favoring either company, we refer to the products as “perovskite test kits.” The two inventors, who are at Lumetallix, have U.S. and European patent applications pending.1
How Does It Work?
The perovskite test kits use a solution of methylamine and hydrobromic acid in >90% isopropanol (household rubbing alcohol is 70% isopropanol). When sprayed on a surface, the compounds in the solution combine with lead to form lead halide perovskite that glows green when exposed to UV light.
Simply squirt or rub a small amount of the solution on a dry material and shine the UV light on it. The kit comes with a UV light. If the solution contacts lead, the resulting lead halide perovskite glows green.
The intensity of the green glow increases with greater amounts of accessible lead. The darker the room, the easier it will be to see.
If the accessible lead is clumped together into small particles, such as on a dust wipe, the lead shows up as individual spots of green surrounded by black.
Professionals and geeks can increase the sensitivity of the technology by using a more intense UV light and a camera with longer shutter times. In theory, it could detect clumps as small as 1,000 atoms.
Check out two peer-reviewed studies, here and here, from the inventors and their team that evaluate the technology. Also, check out their websites for videos, applications, and more details.
Our Take
We see tremendous, perhaps game-changing, potential from perovskite test kits as a screening tool in a wide range of personal and professional applications.
The most exciting of its many applications is to enable anyone to quickly wipe surfaces where they live, learn, play, and work to qualitatively check for lead-dust at comparatively little cost. Those surfaces could be floors where toddlers crawl, as well as toys they play with, parents’ hands that lift them up after work, dishes they eat from, or vehicles taking them to and fro. Additionally, the screening test may prompt people to have blood lead tests for their children or themselves.
Identifying lead-dust is a high priority because it is likely to be ingested in significant amounts, especially for toddlers who often put their fingers in their mouth. The risk can also be high for adults who do not take sufficient precautions when disturbing materials such as old paint, tiles, vinyl, pipes, or circuit boards that contain lead, unknowingly putting themselves and their families at risk.
More importantly, the perovskite test kits have the dual purpose of not only prompting timely cleanups of lead dust but also providing a means to quickly check to determine if a cleanup was effective. While we lack a rigorous analysis, the early feedback from experienced abatement contractors is that the perovskite test kits allow their crews to be much more likely to pass clearance testing based on a lab analysis of dust wipes collected by a third-party. This saves them time and money and reduces the disruption for families they serve. However, it is far too soon to consider them a substitute for lab analysis of dust wipes.
HUD estimates that almost 22 million homes—18.6% of all homes—have dust lead levels over 10 micrograms per square foot (µg/ft2), twice the new EPA action level that goes into effect in January 2026. That dust lead may be not just from deteriorated lead-based paint, but a myriad of sources that include old paint or ceramic tile that is disturbed, contaminated soil that is tracked in, or work clothes brought home.
Done well, it could dramatically expand the demand for contractors who effectively use lead-safe renovation, repair and painting practices or conduct lead-based paint abatement, for lead-based paint inspections and risk assessments, and for labs that can quantify the lead-dust levels.
Lower Cost Than Other Test Kits
The perovskite test kits appears much more sensitive than other lead text kits and cost much less.
- $79 for Lumetallix that says it has can provide 400+ tests2 at a cost of $0.20 each.
- $75 for Fluoro-Spec that says it can provide 170 full tests3 at a cost of $0.44 each.
- $215 for 48 LeadCheck swabs at a cost of $4.48 each.
- $113 for 24 D-Lead test kits at $4.70 each.
The perovskite test kits are also easier to use and have less risk of staining or otherwise damaging surfaces.
What are the Downsides?
Like other test kits, perovskite test kits only work when the solution contacts lead. If the lead is tightly bound to a substrate or behind a glaze or other intact barrier, it will not “see” the lead.
There is not yet sufficient evidence that perovskite test kits can be used to make regulatory determinations, primarily because the agencies have not evaluated the products. However, because many regulatory standards allow relatively high levels of lead (5,000 ppm in old paint, 2,000 in new water faucets and solder, 100 ppm in components of children’s products, and 90 ppm in residential paints), we suspect the kits may be so sensitive that they detect accessible lead that may find lead at levels well below the allowable levels in various regulatory standards. More research is needed.
We see two primary downsides of the perovskite test kits.
- The solution is flammable, posing a risk of igniting fires around electric sources (see below for details). It can also cause serious eye irritation (but not necessarily damage).
- The kit is so sensitive that consumers might overreact to positive results because they don’t recognize that their environment is so pervasively contaminated with lead that we cannot realistically be free of it.
In addition, if the lead is not accessible now because it is insoluble in isopropanol or behind a coating, glaze or other barrier, the user may conclude there is no lead. An XRF is a better tool to measure lead that could be released if the barrier is damaged or otherwise disturbed.
Is it Safe to Use?
Yes, with precautions. The lead test kits contain a 90% isopropanol solution, which is similar, but more concentrated, than household rubbing alcohol (typically at 70%). The solution can cause serious eye irritation and with prolonged exposure to the alcohol, it can cause drowsiness or dizziness. See Safety Data Sheets (SDSs) for Lumetallix and Fluoro-Spec for details and precautions and, of course, follow instructions carefully.
The perovskite test kits must not be used around electrical or other spark producing devices because the solution is a flammable liquid with a flash point of 54oF. That means the solution will catch fire if exposed to a spark at room temperature. If sprayed, it ignites at even lower temperatures. Fortunately, the amount sprayed is less than 0.2 mL, reducing the risk.
Because it is a flammable liquid, the test kit contains a hazardous material that may be restricted in checked or carry-on bags or shipped by airmail. It can be shipped by ground transportation in small quantities (less than a pint in a nonmetal primary container with a screw cap) with sufficient cushioning material to prevent breakage and absorb potential leakage. The primary container and cushioning must be packed in securely sealed secondary packaging. See USPS guidelines.
Is it Legal to Use?
Yes. We understand that earlier this year, EPA asked both companies questions about their perovskite test kit’s compliance with the Section 5 of Toxic Substances Control Act (TSCA) at 15 U.S.C. § 2604.4 EPA appears to have gotten the answers it needed but stay tuned.
The perovskite test kit has not been recognized by any agency to make any regulatory determinations. However, we believe it makes an excellent screening tool to identify whether lead may be present that warrants additional evaluation.
There is some ambiguity whether the person using a lead halide perovskite test kit on paint, interior dust, or soil needs to be certified by EPA5 as a lead-based paint inspector or risk assessor. However, the test kits are not capable of determining whether or not a paint is lead-based paint (meaning it was lead levels were ≤ 5,000 part per million (ppm) and ≤ 1 mg/cm2), or whether it meets the definition of a dust-lead hazard or a soil-lead hazard pursuant to 40 CFR Part 745. Therefore, in our opinion, the person using the test kit does not have to be a certified lead-based paint inspector6 or risk assessor7 to use it, even if compensated for the use.
- Lukas Helmbrecht and Willem Liew Noorduin filed for a U.S. patent on April 4, 2022 and were assigned US 2024/0183786. The same day, they filed for an European Patent on April 4, 2022 and were assigned EP4320427. Both patent applications are titled “Method for Detecting Lead” and are pending. ↩︎
- The estimate is based on the number of squirts from the spray. Actual numbers may vary. ↩︎
- The estimate is based on the number of squirts from the spray. Actual numbers may vary. There is an option to buy an extender for $0.50 to get 500 sprays out of it. ↩︎
- The issue is whether the chemicals in the solution at on the TSCA chemical substance inventory or whether it was covered by a premanufacturing notice to EPA. ↩︎
- Or a state that has been delegated authority by EPA to implement the lead-based paint activities rules. ↩︎
- An inspection is defined as a “surface-by-surface investigation to determine the presence of lead-based paint and the provision of a report explaining the results of the investigation.” ↩︎
- A risk assessment is defined as “(1) an on-site investigation to determine the existence, nature, severity, and location of lead-based paint hazards, and (2) the provision of a report by the individual or the firm conducting the risk assessment, explaining the results of the investigation and options for reducing lead-based paint hazards.” ↩︎