Repurposing vintage items is great, but these items can contain harmful levels of lead, the hazards of which were not as well known at the time. These test swabs can be used to detect the presence of lead on surfaces such as glassware, ceramics, or painted walls. The same test is used in forensic science to detect gunshot residue.

The test is based on the chemical properties of sodium rhodizonate, which is stored in the swab’s tube along with an organic solvent to facilitate the reaction. The rhodizonate ions react with lead to produce a visible color change on the swab ranging from pink to purple. Higher concentrations of lead produce darker and quicker results, providing a semi-quantitative measure of lead presence. This chemical test is extremely sensitive, and can detect even minute concentrations of lead; however, these levels may take longer to react, up to two minutes.

Procedure:

1. Wearing gloves, unwrap a swab and hold it with the pink end pointed up.
2. Snap the pink tip off, waiting a few seconds to allow the solution to flow to the white end and soak the swab tip.
3. Rub the soaked tip against a surface and wait to observe a color change on the swab.
4. Note your observations and dispose of the swab.