Environmental Protection Agency (EPA) Model Lead Based Paint Risk Assessor Practice Test

What color does sodium sulfide field test kits turn when in contact with lead?

1. Red

2. Green

3. Dark grey or black

4. Yellow

The correct answer is: Dark grey or black

Sodium sulfide field test kits are used to identify the presence of lead in various materials, including paint and dust. When sodium sulfide comes into contact with lead, a chemical reaction occurs leading to the formation of lead sulfide, which is known for its dark gray or black color. This color change is a key indicator of lead presence and is utilized in various lead testing protocols. Understanding why the test yields this specific color is essential for accurate assessment. Lead sulfide is often referred to as a black precipitate in chemical reactions involving lead, which is why the dark gray or black appearance signifies that lead has been detected. This characteristic allows assessors to make informed decisions regarding potential lead exposure and consequently implement safety measures. The other color options do not represent the correct reaction of sodium sulfide with lead, reinforcing the importance of recognizing the specific outcome of the test.