3m Lead Test negative for days then turned positive?

Question

I tested some dust for lead using a 3m lead check swab. The test was negative, and I left the testing fluid on the surface for several days because I hadn't gotten a chance to clean it up. I know it was orange minutes after testing, and also orange a couple days after testing. It's maybe a week after testing now and I just found that it has turned pink. Does this mean lead is present?

score 1 · Answer 1 · answered Oct 21 '19 at 19:07

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The 3M site says this

3M™ LeadCheck™ Swabs have no shelf life. Unless the ampoules/vials are cracked, they will have an indefinite shelf life.

In other words, once the vial is broken (which you did to use the tester), it does indeed have a shelf life

answered Oct 21 '19 at 19:07

Machavity

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I agree, if the op is concerned scuff the surface a bit deeper and retest with a fresh kit, their may be 2 or more layers of lead free paint on top depending on the age of the home and how often it was painted.+ – Ed Beal Oct 23 '19 at 14:20

score 0 · Answer 2 · answered Oct 21 '19 at 18:59

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Not necessarily, it probably means the fluid has oxidized over time.

answered Oct 21 '19 at 18:59

Solar Mike

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score 0 · Answer 3 · answered Oct 22 '19 at 00:27

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The fluid is only good for 30 seconds. After that, whatever is says is meaningless.

answered Oct 22 '19 at 00:27

JRaef

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3m Lead Test negative for days then turned positive?

3 Answers3