anyone good at maths and chemistry..?

[NikNak]

Hi all....


I'm after someone who has a few more brain cells than me to work out a health and safety issue.....


It's regarding spraying (relatively) small amounts of IPA (Isopropyl Alcohol).... see data sheet here...

http://www.jmloveridge.com/cosh/Isopropyl%20Alcohol.pdf

but done on a very regular basis...!



this might help too...

http://www.nesc.wvu.edu/ndwc/articles/ot/fa04/q&a.pdf

and this...

http://www.ccohs.ca/oshanswers/chemicals/convert.html


if there's any takers i'll post some more....


Cheers guys


Nick

 

[Chrispy]

health and safety wise, I think it means don't drink it neat, always dilute with orange juice or tonic water and serve over ice. ccasion5:

 

[Phil Pascoe]

ccasion5: ccasion5: Make sure you drink enough before you go blind!

 

[NikNak]

cheers guys.... but not really what i was after...


N

 

[Phil Pascoe]

Sorry, it's a bit late on a Friday night for intelligent comment.

 

[RogerS]

Nick

The maths isn't the issue here. It's knowing what the acceptable limits are for this substance. Until you know that, I don't think you can progress very far.

 

[stevep]

You don't actually say in your original post what you want to know. I would presume its to do with the exposure limits. If so, they are on the msds sheets.

 

[NikNak]

Hi guys....

Sorry if it was a bit vague....

I use IPA quite a bit at work, both on small 'Texwipes' and spray via airbrush. The amount sprayed is approx 10cc at a time (i'll measure/weigh accurately tomorrow). This 10cc is sprayed fairly quicly i.e. dispersed in approx 30 -40 secs, and can be done anywhere between twice in 2 hours to twice every 20 mins... to not at all all day.

The permissible exposure levels are on the data sheets as 400ppm over 8hrs or 500ppm for 15 mins.
here's another data sheet with a little more info.... http://www.sciencelab.com/msds.php?msdsId=9924412

It's not the use on a small texwipe i'm concerned with, its the spraying of the solvent i'm more interested in.

It's used in an area that has 'localised' fume extraction, but i'm not convinced its working as well as it could lets say....

Sooooo...... knowing the 'safe' exposure limits, the amount/volume and time/frequency its used.... where does it fall regards 'safe' exposure..?? make sense..? :?


Nick

 

[Dangermouse]

If it's as toxic as that, wear a full body protection suit with independent circuit air supply and then you wont need to worry about all this faffing about. I really don't think you can give an actuate reply to your question as there are too many variables.

 

[RogerS]

Reading between the lines I am surmising that you are concerned about exposure to this chemical at work and that you think that your employers are perhaps not taking the risk as seriously as they might ?

I don't think we can answer your question because the air needs sampling where and when you spray and that is the only accurate way of determining the ppm at that point in time....or sampled over 15 minutes as you are spraying.

 

[nanscombe]

I can't say that I can make head nor tail of the following info but someone else here might.

At the risk of clouding the issue (pun intended) here's what the CDC (American) think of it.

Respirator Recommendations
NIOSH/OSHA

Up to 2000 ppm:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode£
(APF = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s)
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister
(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)£
(APF = 50) Any self-contained breathing apparatus with a full facepiece
(APF = 50) Any supplied-air respirator with a full facepiece

Emergency or planned entry into unknown concentrations or IDLH conditions:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister
Any appropriate escape-type, self-contained breathing apparatus

And the US department of Labor (sic).

* OSHA PEL

The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for isopropyl alcohol is 400 ppm (980 milligrams per cubic meter (mg/m(3))) as an 8-hour time-weighted average (TWA) concentration [29 CFR 1910.1000, Table Z-1].

* NIOSH REL

The National Institute for Occupational Safety and Health (NIOSH) has established a recommended exposure limit (REL) for isopropyl alcohol of 400 ppm (980 mg/m(3)) as a TWA for up to a 10-hour workday and a 40-hour workweek and a short-term exposure limit (STEL) of 500 ppm 1225 mg/m(3)) for periods not to exceed 15 minutes. Exposures at the STEL concentration should not be repeated more than four times a day and should be separated by intervals of at least 60 minutes [NIOSH 1992].

* ACGIH TLV

The American Conference of Governmental Industrial Hygienists (ACGIH) has assigned isopropyl alcohol a threshold limit value (TLV) of 400 ppm (983 mg/m(3)) as a TWA for a normal 8-hour workday and a 40-hour workweek and a short-term exposure limit (STEL) of 500 ppm (1230 mg/m(3)) for periods not to exceed 15 minutes [ACGIH 1994, p. 24].

 

[monkeybiter]

As said above the original risk assessment for the operation/s should include some real data rather than just assumptions.
Working indoors there should be effective extraction at the point of use or as second best you would need a respirator with the correct filters.
The extraction should have airflow monitoring to prove it's working.
You also should be wearing resistant gloves and goggles/glasses.

We use IPA by the tonne at work so I'll have a chat with someone directly involved to see if I can glean anything more specific.

 

[NikNak]

Reading between the lines I am surmising that you are concerned about exposure to this chemical at work and that you think that your employers are perhaps not taking the risk as seriously as they might ?

I think maybe Roger has hit the nail on the head..... :wink:


I don't want to mention names or places or what i do as i now have a referral to see a dermatologist.... but that's not for another 2 months..!! (NHS don't ya know...)

The particular process is carried out in a positive pressure environment... to keep dust to a minimum. There IS localised extraction where the IPA is sprayed, taken out of the pressurised area then exhausted into the lab (i have queried the 'filter' as to whether its a particle filter or a fume filter and have been told "i'm sure its the right one...!). I/we DO use/wear all the PPE provided... i.e lab gowns, safety glasses, gloves etc.

But all this doesn't stop airborne 'invisible 'mist' landing on your face..... which is my particular problem. I have developed a very prominent and obvious skin rash on my cheeks and forehead. And for someone who has extremely oily and greasy skin, and knowing that IPA can rid the skin of oils very effectively, its seems a probable cause to me.

For someone who works for a 30bn euro worldwide company you'd think they'd want to get to the bottom of this very quickly and send me off for patch testing NOW..!! or could it be they know theres a 'problem' and are just hiding from it...

I've worked with chemicals / resins all my life so am aware of any 'dangers' etc, and can honestly say i've never in all my 40 years experienced anything quite like this.

Monkeybiter.... thanks for that, look forward to your reply....



Nick

 

[JakeS]

But all this doesn't stop airborne 'invisible 'mist' landing on your face..... which is my particular problem. I have developed a very prominent and obvious skin rash on my cheeks and forehead. And for someone who has extremely oily and greasy skin, and knowing that IPA can rid the skin of oils very effectively, its seems a probable cause to me.

I'd be kind of surprised, since alcohol is pretty volatile at the best of times and in a misted form it should evaporate in seconds. It's been a while since I did Chemistry, but I think that the reason it cleans oils off easily is that it is a much better solvent for oils than water, meaning that the oils don't react with it but simply dissolve in it. But when the alcohol evaporates, the oils should simply be left behind...


In my empirical experience, the main hazard with spraying alcohol (I used to use it fairly extensively as a solvent for acrylic paints through an airbrush) is more inhalation; IIRC the vapour/mist will get into your bloodstream through your lungs a lot quicker than drinking spirits does, so I found myself lightheaded after ten minutes or so until I (quickly!) started using a proper respirator. If significant quantities of the vapour are getting out of the booth - and especially if you're doing anything which requires concentration and/or fine motor control for safety reasons - I'd ask for an organics-filtering respirator - A2 or A3.

 

[monkeybiter]

At my place of work IPA is handled within steel vessels/pipework in very well vented buildings or completely outdoors. No additional PPE is specified above the usual chem. resist. gloves/overalls and safety glasses/visors. Occasionaly there is a smell. Under normal circumstances there is no need for respirators.
We have a very good relationship with the HSE and they are happy with all of this. There are no anecdotal reports of any skin irritation.
However you work in a more enclosed environment from the sound of it, and your extraction is recirculating. There should be an indication that the air flow is at or above a minimum required value [dependent on the fume cupboard etc.] and there should be filter type and service/replacement dates visible/accessible.
See your safety rep. if you can't get any satisfaction from above.