# Flashing Blue Lights On Pills At Factory
**URL:** https://boards.straightdope.com/t/flashing-blue-lights-on-pills-at-factory/537509
**Category:** Factual Questions
**Created:** [April 27, 2010, 12:37pm UTC](https://boards.straightdope.com/t/flashing-blue-lights-on-pills-at-factory/537509 "2010-04-27T12:37:04Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Markxxx](https://boards.straightdope.com/u/Markxxx)
#### Post date: [April 27, 2010, 12:37pm UTC](https://boards.straightdope.com/t/flashing-blue-lights-on-pills-at-factory/537509/1 "2010-04-27T12:37:04Z")
I have a temp job in a factory and they make generic drugs.
Anyway today I was on a line way at the end where they have final package and while I was waiting I noticed at the beginning of the line, the pills came down onto the conveyor belt. Then they stopped under a, for lack of a better word ledge. Then I could see three bright flashes of blue light. The the pills continued on their happy way to me waiting to pack them.
My question is what is that flashing blue light? I didn’t have time to ask anyone at the factory. Is it ultraviolet light? I was thinking it was a way of getting rid of germs?
Any ideas?
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### Author:  [@Fritz](https://boards.straightdope.com/u/Fritz)
#### Post date: [April 27, 2010, 12:41pm UTC](https://boards.straightdope.com/t/flashing-blue-lights-on-pills-at-factory/537509/2 "2010-04-27T12:41:33Z")
Vision system to determine that the pills were whole or no defects before final packaging? That is, quality control check.
Edited to add: are the pills inside blister packs yet or are they loose?
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### Author:  [@Smeghead](https://boards.straightdope.com/u/Smeghead)
#### Post date: [April 27, 2010, 1:08pm UTC](https://boards.straightdope.com/t/flashing-blue-lights-on-pills-at-factory/537509/3 "2010-04-27T13:08:49Z")
UV light isn’t going to kill anything that quickly.
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### Author:  [@Leaffan](https://boards.straightdope.com/u/Leaffan)
#### Post date: [April 27, 2010, 1:35pm UTC](https://boards.straightdope.com/t/flashing-blue-lights-on-pills-at-factory/537509/4 "2010-04-27T13:35:19Z")
I worked for a company that manufactured blue lasers for food inspection purposes, among other things. This is no doubt some sort of QA check.
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### Author:  [@cornflakes](https://boards.straightdope.com/u/cornflakes)
#### Post date: [April 27, 2010, 1:38pm UTC](https://boards.straightdope.com/t/flashing-blue-lights-on-pills-at-factory/537509/5 "2010-04-27T13:38:56Z")
It’s a QC check. The line probably uses blue light because the pill’s shape is more easily seen by the imaging system when blue light is used.
They could have used white light instead and put a filter on the CCD. I’m assuming that they did it this way either because the line is exclusively used for this pill (other pills may show up better under other wavelengths, but that flexibility isn’t needed), or the system came with blue light out of the box and it works.
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### Author:  [@Philster](https://boards.straightdope.com/u/Philster)
#### Post date: [April 27, 2010, 1:43pm UTC](https://boards.straightdope.com/t/flashing-blue-lights-on-pills-at-factory/537509/6 "2010-04-27T13:43:57Z")
Quick blue-light test will show contaminants which – if present-- are picked up by optical equipment in sub-seconds. Think of a really fast black-light test – the kind you see on CSI-type shows.
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### Author:  [@Markxxx](https://boards.straightdope.com/u/Markxxx)
#### Post date: [April 28, 2010, 1:40am UTC](https://boards.straightdope.com/t/flashing-blue-lights-on-pills-at-factory/537509/7 "2010-04-28T01:40:04Z")
Thanks for the info. Yeah the pills are loose at that stage. I was just wondering why the three flashes of blue light.
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### Author:  [@GoodOmens](https://boards.straightdope.com/u/GoodOmens)
#### Post date: [April 28, 2010, 3:53pm UTC](https://boards.straightdope.com/t/flashing-blue-lights-on-pills-at-factory/537509/8 "2010-04-28T15:53:10Z")
I would guess there are 3 flashes so that there’s redundancy in the check. During the flashes are the pills still in motion (rolling, being agitated)? If so, each flash sees a different view so there’s a greater chance of seeing flaws.