Sciencemadness Discussion Board

test strips/device to detect phosgene

teodor - 22-9-2021 at 08:23

I'd like to have such test strips to make sure I am safe when making experiments wich use chlorinated hydrocarbons like CCl4, CHCl3, CH2Cl2, C2H2Cl4.
I know they exist and I found the article https://doi.org/10.1039/C7CC05313D which has a good review of other articles & compounds which can be used to make them.
Does anybody know any supplier which sells such strips?
I plan to use them inside a fume hood so they can have lower sensitivity compared with what is needed to test the air in the laboratory space.
I also can consider an electronic device if it is not VERY expensive.
I understand that it is not what everybody absolutely needs but just something which can make me more comfortable when working with some group of compounds.

unionised - 22-9-2021 at 11:06

Does this help?
https://en.wikipedia.org/wiki/Chloroform#Conversion_to_phosg...

Plunkett - 22-9-2021 at 11:28

Have you looked at Dräger tubes? Dräger Tubes are glass vials filled with a chemical reagent that reacts to a specific chemical or family of chemicals. A calibrated 100 ml sample of air is drawn through the tube. If the targeted chemical(s) is present the reagent in the tube changes color and the length of the color change typically indicates the measured concentration. They are a bit pricey for the hobbyist.
https://www.gasdetectionwarehouse.com/draeger-gas-detector-t...

teodor - 23-9-2021 at 05:21

Quote: Originally posted by unionised  
Does this help?
https://en.wikipedia.org/wiki/Chloroform#Conversion_to_phosg...


diphenylamine + dimethylaminobenzaldehyde method is not specific to phosgene as far as I know. Being probably a good method to test pure chloroform (because you have either pure chloroform or pure chloroform with phosgene) it doesn't necessarily suitable for air testing which can contain NOx, SOx, O3, organic and inorganic acids etc.

Quote: Originally posted by Plunkett  
Have you looked at Dräger tubes? Dräger Tubes are glass vials filled with a chemical reagent that reacts to a specific chemical or family of chemicals. A calibrated 100 ml sample of air is drawn through the tube. If the targeted chemical(s) is present the reagent in the tube changes color and the length of the color change typically indicates the measured concentration. They are a bit pricey for the hobbyist.
https://www.gasdetectionwarehouse.com/draeger-gas-detector-t...


It would not be expensive if could be used for prolonged testing mode, like several days or at least several hours pumping the air through it, but I am afraid these devices can be used only once with 100ml of air and then require replacing.

BromicAcid - 23-9-2021 at 09:13

This is what we use at work

https://dodtec.com/phosgene-3-day-badge-without-control-wind...

teodor - 23-9-2021 at 09:45

Quote: Originally posted by BromicAcid  
This is what we use at work

https://dodtec.com/phosgene-3-day-badge-without-control-wind...


Looks interesting. How fast I can expect the color change at the dangerous level?

I checked the site and it costs $114 to send to the Netherlands. More than the price of the pack of 50 badges. Inside US the shipping cost is around $11.
So, if somebody who lives in US is interested in the group buy (can get and send me a part of the pack by usual post) please let me know. While I will look to other alternatives.

BromicAcid - 23-9-2021 at 09:48

Change is rapid, carbonyl chlorides/ chloroformates / chlorothiolformates all give interference results (slightly different colors). I used them for years before moving to a different part of the company so I was pretty good at determining exposure by looking at the intensity of the red dot but they also have a chart correlating to dose. The badges themselves seem reasonably priced but you're right - shipping is killer.