Detecting Chlorine In Materials To Be Cut

Hi All,

Just came across this short video on how to make sure the material you’re going to laser will not emit chlorine gas (which can be fatal if inhaled, even in small quantities).

Hope someone finds it helpful…

Jerry Kornbluth


Good video and great advice. Wish I would have seen this years ago. I had 2 CO2 lasers and was using one to cut vinyl to make signs. Thank god I exhausted the fumes outside. The next day I came out to do some work and couldn’t figure out why one machine was all rusty. It looked like it was sitting outside in the rain for a couple of weeks. Daaa. :upside_down_face: :upside_down_face:

I would recommend everyone to do this test if you plan to engrave or cut any type of plastic.

Thanx for posting this video!!


Thanks for responding,
Jerry Kornbluth

I don’t trust anything that I don’t know it’s origin.

Most plastics create some kind of unhealthy chemical, not just chlorine. ABS produces hydrogen cyanide…

It only tests for chlorine. And they are probably breathing it when they/you burn it with a torch.


Good point

Laser used to cut vinyl… I think this was about a $20k machine…


1 Like

Wow, that looks pretty ugly…

I think that pretty well covers it… :crazy_face:


So, I was thinking it might be ok to use thin vinyl (the stuff that’s used on a vinyl drag knife cutter) but applied to glass as a mask for later sandblasting. Not ok at all/ever?, or occasionally should not cause an issue. ??

They make a type of vinyl that can be lased, I’ve head people talk about it.

Not sure where to get it, but any use will corrode the machine if it’s not intended for use in a laser.

A girl got an 80 watt machine and drew out a design for her boyfriend for an old lp record. She cut out the design and the next day her machine was toast…

I’d refrain from any unless it is know that it’s safe.

Take care


1 Like

Thanks Jack, good thing I came across this thread first as I was considering doing a small test today.

Looks like you can get pvc-free vinyl:

What I have already is ORACAL 651 vinyl. I guess I should just find some copper wire and test it.

As a follow up, I performed the Beilstein test and I can confirm that my vinyl adhesive ORACAL 651 does indeed contain PVC.

I was hoping to get away with laser cutting it, and thought it would be ok if I was able to vent the fumes, but certainly won’t use it now if it’s going to damage my laser.

Also, if this is critical it might be a good idea to have the “Beilstein Test” as a “sticky” somewhere on this forum.


1 Like

I think what is key here is the efficacy of your machine’s ventilation system. Gentle ventilation won’t do the job. But a good, strong, over engineered suction system(such as I have) may well do the job.

But in any case this has been a good discussion and a warning we should take to heart.

1 Like

Useful information from Wikipedia

Beilstein test

From Wikipedia, the free encyclopedia

Jump to navigationJump to search

The Beilstein test is a simple qualitative chemical test for organic halides. It was developed by Friedrich Konrad Beilstein.[1]

A copper wire is cleaned and heated in a Bunsen burner flame to form a coating of copper(II) oxide. It is then dipped in the sample to be tested and once again heated in a flame. A positive test is indicated by a green flame caused by the formation of a copper halide. The test does not detect fluorine/fluorides.

This test is no longer frequently used. One reason why it is not widely used is that it is possible to generate the highly toxic chloro-dioxins if the test material is a polychloroarene.[2]

An alternative wet test for halide is the sodium fusion test — this test converts organic material to inorganic salts include the sodium halide. Addition of silver nitrate solution causes any halides to precipitate as the respective silver halide.

The problem is not really the chlorine, if I understand the process correctly.

The chlorine combines with moisture and produces hydrochloric acid, which is highly corrosive to your machine. Even with a hurricane, that acid would find all of your nice bearings and surfaces… Same thing that happens when you inhale it, becomes acid from the moisture of your lungs.

IMHO, even if you could vent it cleanly, is it OK to vent chlorine gas for your neighbors and their kids to inhale.? Just because it’s out of your machine or home, doesn’t release you from being responsible for what you spew into the air others must breath. Would you want them to do it to you? And of course without your knowledge.


Hi Jack,
I admire your concern for the well being of others. Clearly I can learn from you.

But, on the other hand, I am always careful to distinguish between alarmism and sensible caution. Sensible caution requires me to be well informed, well prepared, be fully aware of the context and weigh these against my goals so that I can make intelligent choices. In my case I have a good ventilation system, do only moderate amounts of such cutting and in my environment there is not the slightest danger to my neighbours(or even to myself). Given these factors, I think it is fair to say I have made an intelligent decision, considering my context and goals.

More generally, the best we can do is make the facts available, properly ventilate[!] them in a discussion and then leave the matter to the individual, trusting that he will make the best decision, given his circumstances.

I’m an American, I believe in individual freedom of choice. It will corrode the machine, small amount of cutting, small amount of corrosion.

Everybody makes better decisions with better data or information…

Good luck


None detectable in my machine so far, but, who knows, in a few years I may find some. But I doubt it, given that I don’t do industrial level cutting and I use a powerful exhaust fan.

The OP sounded a useful caution and I certainly think it is something we should keep in mind. I wish I had a way to actually measure the concentrations of harmful organic halides so that we could move the discussion out of the realm of speculation. My entire working life was predicated on the simple motto - make measurements, not assumptions.

Agreed, too bad so many thing don’t allow easy measurement, such as the lps output voltage. Then you have nothing but assumptions.

As a ham radio operator, you make do with what you have and figure out how to measure it with parts on hand…

When you combust stuff, there is an extremely wide range of chemicals produced… of course we’d probably find out everything is harmful…


1 Like

You guy are aware, that to cut vinyl there are the cutting plotters?! :slight_smile: