Testing Precautions for LeadCheck Swabs:
Each LeadCheck® Swab contains a lead reactive dye and a buffer solution
containing ingredients designed to maximize the sensitivity and specificity of the reaction.
None of the materials used in LeadCheck® Swabs are hazardous. The chemistry is based on known
principles. Under the conditions of the reaction in LeadCheck® Swabs, the reactive dye is
highly specific for lead forming a pink or red colored ion association compound. The
color of the complex increases almost linearly with increasing metal ion concentration
when the reactive reagent concentration is kept constant as it is in LeadCheck® Swabs.
In the presence of certain chemicals additional test precautions are required.
- Sulfates: Most commonly found in plaster, Sulfates can block the color development on the test surface and LeadCheck® Swab tip.
Cleaning the surface to remove plaster dust is usually all that is required. PB-08 Plaster, Stucco
- Tin: Most commonly encountered when testing solder, high levels of tin can turn the Swab Tip purple. When lead is
present the LeadCheck® Swabs tip will turn pink before turning purple. For a full discussion click
the following link: PB-01P Solder.
- Red Paint: Red paint pigments can come off of test surfaces - coating the Swab.
PB-12 Red Paint, PB-07 Red Lead.
- Delayed color reaction: Occurs when very low levels of lead are present PB-22R1 Low Level Testing (0.1%), or when lead does not easily leach from the surface
PB-05R1 Chromate Paint. If pink is seen anywhere on the LeadCheck® Swab tip or
where the tip contacted the surface the test is positive for lead
|