Thank you for such a well-researched and carefully explained video. I liked, especially, that you showed possible places of misunderstanding which have led to confusion between trivalent chromium and hexavalent chromium. I appreciated that your gentle way of explaining did not ridicule anyone for holding misinformation; it only sought to clarify. Very, very well done. Thanks again.
Excellent video that was recommended to me as I also have seen the comments on various FB posts that was clearly misinformation. I feel so much better now. Thank you for making this video!
Thank you so much for this amazing video!! This was much needed in our type of work. So many people were scared to engrave chrome tanned leather. This clears it all up!
Thank you for an outstanding explanation and discussion of laser leather issues, especially concerning chrome-tanned. You've clearly discussed the science involved, with references to back it up. I've spent way too much time arguing online that it is safe, but now I'll just refer to your youtube discussion. Actually, I've pretty much given up on convincing anyone and just figure that their misunderstanding means there's less competition.
Do yall vent outside or use one of those filtration boxes? Now I will say, I talked to Weaver and they don't reccomend it. I guess it depends on how you filter it away.
@@PGHATCO I gotcha. Well this video definitely eased my mind as far as the chrome tanned leather. Congrats on the new building and much continued success! Yall are an inspiration to a young entrepreneur.
I actually spoke with Tandy Leather on the phone today. They are still saying that the fumes created from laser engraving chrome tanned leather are not safe to breathe and they recommend you not be in the same room with it being engraved. So it's still such a conflicting issue!
"Results indicate that trivalent chromium in Cr2O3 could be readily converted to hexavalent chromium at a temperature range of 200-300 degrees C, with conversion rates of up to 50% in 12 h."
"Hexavalent chromium can irritate the nose, throat, and lungs. Repeated or prolonged exposure can damage the mucous membranes of the nasal passages and result in ulcers. In severe cases, exposure causes perforation of the septum (the wall separating the nasal passages)." www.osha.gov/hexavalent-chromium/health-effects
I'm unclear about something. The studies and the discussion talk about the amount of hexavalent chromium in the leather after cutting or engraving it in a CO2 laser. But the concern is what's given off *during* combustion while it's being cut or engraved and whether *that* is toxic to the operator or harmful to the machine.
Hi Deborah, I did see your comment come up as I get an email notification when a comment is posted but then it disappeared. I’m not sure why but I hope it comes back again. Below is the original comment and my reply. Thank you for the excellent video. I do not own a laser but I use the Trotec Speedy 300 80W laser at the public library. Needless to say, I don't want to endanger the health of the staff and patrons to make/engrave a pair of moccasins. I shared your lovely video with a Facebook Trotec users group. I hope you don't mind. I hoped to hear others were now laser engraving & cutting chrome-tanned leather but that was not the case. You mention trivalent chromium is used nowadays. However, is hexavalent chromium or sodium dichromate still used anywhere in the world? A lot of leather comes from India. Is there any risk leather from India (Asia) is tanned using hexavalent chromium or sodium dichromate? How can one verify trivalent chromium was used? Several months ago, I bought veg tan leather from Tandy, but then returned it when I learned it was 1% chrome-tanned. Why would both be used? Thank you. I hope you are well and I look forward to hearing from you. FYI, I live in a suburb of Chicago, Illinois. Reply: Thanks for the comment Deborah, and for sharing my video with the Trotec user group. No problem at all for you to do this. I’m not sure about which salt is used these days but I know someone in the industry to I will reach out to them. I would guess there are tanneries that are using salts that contain hexavalent chromium. India is a big producer and I would guess that, like in South Africa, there are policy guidelines in terms of health and safety, even though there are not the stringent 3 ppm limits as in the EU. But I have no idea. There is the risk that in any country, there are going to be shotgun tanneries that take short cuts and endanger the health of their workers and the end-user. Since the EU has legislated a maximum of 3ppm in leather products, they use an accept test for this. I don’t know how costly or difficult this is to perform but there you go. I have heard that the test is only sensitive to 3ppm (not less) which is why they set this number. In other words, they want to ensure that there is no hexavalent chromium present. Not sure whether this is true, however. About your returning the veg tan leather that you bought from Tandy’s, it’s possible chrome tanning was used along the way, even though it might be sold as a ‘vegtan’ leather. I cover the variation in one of my other videos that might help in terms of an explanation. As far as I understand, there are two phases of the tanning process. While some tanneries use only vegetable tannins from start to finish, another tannery (that does not have the capacity to treat raw hides) might buy the chrome tanned hides (called a ‘wet blue’) and then treat it with vegetable extract in the second phase and sell this as vegtan. Such a facility would be called a finishing plant as far as I know. As I describe in the video, this might also be sold as a ‘veg re-tan’, as is the case with some outlets in South Africa but outlets may not alert users to the fact that the first phase was chrome tanned. I’d be interested to know how you found out that it was 1% chrome tanned. All the best, From Cape Town
Thank you for such a well-researched and carefully explained video. I liked, especially, that you showed possible places of misunderstanding which have led to confusion between trivalent chromium and hexavalent chromium. I appreciated that your gentle way of explaining did not ridicule anyone for holding misinformation; it only sought to clarify. Very, very well done. Thanks again.
Thanks for the positive comment @Curiosity Draws Me, I appreciate it.
Excellent video. Thank you for dispelling this myth.
Thanks for your informative information. It was a sort of matter of my concern when lasering the leathers
I just got a laser cutter/engraver setup in my shop today. This was incredibly helpful. Thank you for this great information!
Thank you. It was a pleasure!
Excellent video that was recommended to me as I also have seen the comments on various FB posts that was clearly misinformation. I feel so much better now. Thank you for making this video!
Thank you Kim.
Thank you for the great well researched info. I was wondering if the same outcome occurs when using a diode laser?
Thank you so much for this amazing video!! This was much needed in our type of work. So many people were scared to engrave chrome tanned leather. This clears it all up!
Thank you for this explanation!
Thank you for this excellent and in depth explanation. It is nice to find someone who knows what they are talking about.
Just starting out in the leather engraving field. Thank you for breaking it all down for us. Much appreciated!
This is so helpful. Thank you for sharing!
Thank you for an outstanding explanation and discussion of laser leather issues, especially concerning chrome-tanned. You've clearly discussed the science involved, with references to back it up. I've spent way too much time arguing online that it is safe, but now I'll just refer to your youtube discussion. Actually, I've pretty much given up on convincing anyone and just figure that their misunderstanding means there's less competition.
Thanks George! Yes, less competition is a benefit 😅
Thanks for this very depth analysis. We have been using chrome tanned leather and get lots of warnings from other crafters.
Do yall vent outside or use one of those filtration boxes? Now I will say, I talked to Weaver and they don't reccomend it. I guess it depends on how you filter it away.
@@RealDustyChandler We have an industrial filtration system we had built by FUMEX
@@PGHATCO is that what yall were using when you were in your garage with the 2 Glowforges?
@@RealDustyChandler no we have the GF filter system on those
@@PGHATCO I gotcha. Well this video definitely eased my mind as far as the chrome tanned leather. Congrats on the new building and much continued success! Yall are an inspiration to a young entrepreneur.
Thank you for explaining it. Great video 👍
Amazing content! Looking forward to future videos. 😊
Thank you cleared up a mystery
Thanks so much for a great video, appreciate you sharing such educational information with us!
I actually spoke with Tandy Leather on the phone today. They are still saying that the fumes created from laser engraving chrome tanned leather are not safe to breathe and they recommend you not be in the same room with it being engraved. So it's still such a conflicting issue!
Very informative, it is nice to have Science injected into the conversation.
"Extent of oxidation of Cr(III) to Cr(VI) under various conditions pertaining to natural environment"
"Results indicate that trivalent chromium in Cr2O3 could be readily converted to hexavalent chromium at a temperature range of 200-300 degrees C, with conversion rates of up to 50% in 12 h."
"Hexavalent chromium can irritate the nose, throat, and lungs. Repeated or prolonged exposure can damage the mucous membranes of the nasal passages and result in ulcers. In severe cases, exposure causes perforation of the septum (the wall separating the nasal passages)."
www.osha.gov/hexavalent-chromium/health-effects
I'm unclear about something. The studies and the discussion talk about the amount of hexavalent chromium in the leather after cutting or engraving it in a CO2 laser. But the concern is what's given off *during* combustion while it's being cut or engraved and whether *that* is toxic to the operator or harmful to the machine.
What is the reason you keep deleting my respectful comments and questions? Please explain. Thank you.
Hi Deborah,
I did see your comment come up as I get an email notification when a comment is posted but then it disappeared. I’m not sure why but I hope it comes back again. Below is the original comment and my reply.
Thank you for the excellent video. I do not own a laser but I use the Trotec Speedy 300 80W laser at the public library. Needless to say, I don't want to endanger the health of the staff and patrons to make/engrave a pair of moccasins. I shared your lovely video with a Facebook Trotec users group. I hope you don't mind. I hoped to hear others were now laser engraving & cutting chrome-tanned leather but that was not the case. You mention trivalent chromium is used nowadays. However, is hexavalent chromium or sodium dichromate still used anywhere in the world? A lot of leather comes from India. Is there any risk leather from India (Asia) is tanned using hexavalent chromium or sodium dichromate? How can one verify trivalent chromium was used? Several months ago, I bought veg tan leather from Tandy, but then returned it when I learned it was 1% chrome-tanned. Why would both be used? Thank you. I hope you are well and I look forward to hearing from you. FYI, I live in a suburb of Chicago, Illinois.
Reply: Thanks for the comment Deborah, and for sharing my video with the Trotec user group. No problem at all for you to do this. I’m not sure about which salt is used these days but I know someone in the industry to I will reach out to them. I would guess there are tanneries that are using salts that contain hexavalent chromium. India is a big producer and I would guess that, like in South Africa, there are policy guidelines in terms of health and safety, even though there are not the stringent 3 ppm limits as in the EU. But I have no idea. There is the risk that in any country, there are going to be shotgun tanneries that take short cuts and endanger the health of their workers and the end-user.
Since the EU has legislated a maximum of 3ppm in leather products, they use an accept test for this. I don’t know how costly or difficult this is to perform but there you go. I have heard that the test is only sensitive to 3ppm (not less) which is why they set this number. In other words, they want to ensure that there is no hexavalent chromium present. Not sure whether this is true, however.
About your returning the veg tan leather that you bought from Tandy’s, it’s possible chrome tanning was used along the way, even though it might be sold as a ‘vegtan’ leather. I cover the variation in one of my other videos that might help in terms of an explanation. As far as I understand, there are two phases of the tanning process. While some tanneries use only vegetable tannins from start to finish, another tannery (that does not have the capacity to treat raw hides) might buy the chrome tanned hides (called a ‘wet blue’) and then treat it with vegetable extract in the second phase and sell this as vegtan. Such a facility would be called a finishing plant as far as I know. As I describe in the video, this might also be sold as a ‘veg re-tan’, as is the case with some outlets in South Africa but outlets may not alert users to the fact that the first phase was chrome tanned. I’d be interested to know how you found out that it was 1% chrome tanned.
All the best,
From Cape Town