Ventilation in the metal shop

Metal Shop
#22

What is this in reference to?

#23

The SDS for hexavalent chromium

Sure wish I could spell better at times.

#25

Here at the bottom of page 2 under United States EPA Regulatory Information:

https://www.eraqc.com/DesktopModules/ERAMSDS/ViewPDF.aspx?id=155b96c9-3b91-4b0f-8fb9-4589ba4cb658

JAG “A Hex On Your Chromium” MAN

#26

Yep, that was the only direct one I could find. Granted it is for the actual chemical. Not welding/cutting fumes.

#27

Lol, so the question of the day is, What is your shoe size?

#28

Tim,

Lol, so the question of the day is, What is your shoe size?

Let’s just be glad it was his shoe he was comparing the vent to…

JAG “You Know What They Say About The Size Of Your…” MAN

#29

Sorry to be an ignoramus, but maybe you can help me with some of it.
Where does one find the “health safety code of 2” on the SDS (assuming the link provided by @JAGMAN has that information)?
And where can I find more info about the number? What scale is it on? What is it implied to be rating?
I thought I knew a bit about SDS, but apparently it’s been too long since I exercised that part of my brain, or I never knew what I once thought I knew…

Thank you!

EDIT: found this
https://www.osha.gov/Publications/OSHA3514.html
Still not grasping what you meant…

#30

The former MSDS & now present SDS would have the hazard communication on it. The safety diamond (going off memory here) has your different hazards on it. They rate from 0-4, 4 being the highest hazard. It has fire, reactivity, health & special hazards all on it. The SDS shows at the bottom of the page,these hazards. Someone correct me if I’m wrong, it’s been 14 years since I took OSHA 30 class with Haz Comm.

#31

Important to note that this is an SDS for an aqueous solution of K2CrO4 (dissociates in solution to yield Cr(VI)) and the SDS doesn’t contain information for dust containing Cr(VI).

It also states plainly (Section 2, Hazards Identification) K2CrO4 is classified as a GHS/OSHA HCS Class 1B carcinogen, which I had to look up: https://en.wikipedia.org/wiki/Carcinogen#Globally_Harmonized_System

Edit: I’m starting to lose track of why we’re discussing this, really… City said get a professional to design a ventilation system if you want to plasma cut, so we have to (if we want to plasma cut). That ventilation system, since there are welders producing fumes, can easily accommodate the welders for minimal cost increase, when compared to a dedicated system later.

1 Like
#32

Mathew,

Important to note that this is an SDS for an aqueous solution of K2CrO4 (dissociates in solution to yield Cr(VI)) and the SDS doesn’t contain information for dust containing Cr(VI).

Thank you for making note of that, but look at the concentration of 1 kG per L - this is a fairly strong solution and the respiratory irritation warning on the sheet means that the fumes from said solution are still hazardous. I can guarantee that any fumes are small enough from a PM2.5 standard to bypass the paracellular junctions in the epithelial cells of the alveoli (air sacs in the lungs) to go DIRECTLY into the bloodstream so I would consider this the equivalent of any other form of inhalation.

Also, ANY significant levels of particulate matter in the PM2.5 range is a health hazard which is why I wear a P100 respirator with lead / asbestos NIOSH filters in the wood shop and when using the blast cabinet. (I keep one in my truck)

If you want to read a VERY detailed epidemiological analysis of the carcinogenicity of Hex Chromium, then please check out this doc and let me know what your conclusion is:

https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=FEDERAL_REGISTER&p_id=18599

Edit: I’m starting to lose track of why we’re discussing this, really…

I can appreciate that perspective, but I do find the subject interesting. (which is why I joined DMS in the first place)

But agreed, let’s focus back on the ventilation because whatever the perceived or real health hazards are, let’s freshen up the air a bit.

JAG “Breathing Easy With HEPA” MAN

P.S. Nice find on that link for the Globally Harmonized System of Carcinogens - I will use for future reference

1 Like
#33

We’re on the same page - it seemed like the intent of the SDS posted was to mitigate the hazard potential, not support it. It seems that the NFPA/HMIS Rating seems to be subjective and is inconsistent across different SDS for K2CrO4:
http://www.sciencelab.com/msds.php?msdsId=9927403 (granular solid, 3)
http://avogadro.chem.iastate.edu/MSDS/K2CrO4.htm (solid, 2)
I don’t know enough about the NFPA/HMIS rating system to opine on the discrepancy.

I do too, hence the research and response effort. I think the notion to forgo ventilation because it isn’t dangerous enough isn’t right.

1 Like
#34

Agreed and in fact I feel that wearing a respirator if you are doing more than casually walking through the wood/metal shop areas is a good idea. We have box of N95s by the blast cabinet last I checked, but the P100s are superior. You can’t depend on any ventilation system to completely keep the crap out of your lungs - protect yourself.

http://www.amazon.com/gp/product/B000FTEDMM?psc=1&redirect=true&ref_=oh_aui_search_detailpage

JAG “NBC Suit for Halloween” MAN

P.S. Helps with paint/solvent fumes as well IF you use the 2097 organic fume filters (this mask actually comes with 2091s which are for particulate matter only despite what the photo shows)

#35

I don’t believe anyone has made the claim that we should forgo ventilation. But some of us are not willing to suspend welding activities until that task gets accomplished, if it ever does. Barring a letter agency telling us we can’t, there is no reason we shouldn’t proceed to use the equipment we have, in much the same way it has always been used here.

In last nights metal shop meeting, Lee said they have repaired the Lincoln fume filter, so that will be put in operation again soon. Which is all we need for welding, even in a commercial shop managed under OSHA rules.

3 Likes
#36

Ouch, missed it. I wanted to be there.

1 Like