Rather than the bone/blood I’d be more worried about the exposure to biological agents. You can assume that any meat, no matter how clean has some microbiological contamination which might pose a risk. The problem is that this risk is difficult to quantify: you won’t know (and it would be difficult to find out) what organisms are present and what actual risk they pose.
It is not just a respiratory risk but a general hygiene risk, as well, with the splatter being deposited on surfaces including the operative themselves. It is hard to judge what the risk from the splatter might be as some microorganisms can remain hazardous for ages and other die very quickly once they have dried out. As precaution I’d think about some sort of respiratory protection as least while using this circular saw. I am not sure if this this can be controlled by the use of LEV.
You have raised good point but I don’t think that there is a categorical answer.

How is the saw guarded?

Hi
This gets really depressing. I was concerned about bacterial risks in meat process plants and I have just come across this article http://www.researchgate....packing_plants_An_update
Which indicate that there might be a risk from viruses carried on carcasses which I hadn’t even thought about. RPE looking even more important.
See https://www.osha.gov/SLT...g/hazards_solutions.html for more.

You are probably aware of this site.
http://www.bmpa.uk.com/Content/guidance.aspx?g=51

Doesn't answer your specific question but might give you some pointers by default?

¨Creutzfeldt-Jakob disease (CJD)
Background Information
CJD is a very rare, fatal neurodegenerative
disease, which is thought to be caused by
the build up of an abnorm
al form of the na
turally occurring ‘prion’ protein in the
brain.
There are four types of CJD (variant, spor
adic, inherited and iatrogenic), of which
only variant CJD (vCJD) is an
occupationally acquired disease.
CJD belongs to a group of Transmissible
Spongiform Encephalopa
thies (TSEs) which
affect humans and animals.
Organism:
Bovine Spongiform
Encephalopathy (BSE) agent
Incidence and Transmission:
The first reported case of vCJD was in
1996 and since then there have been alm
ost
200 deaths in the UK.
vCJD is strongly linked to exposure to – and
in particular consumption of – beef or
beef products from cattle suffering from BSE or ‘mad cow disease’. The first reported
case of BSE in cattle in the UK was in
1986. BSE was spread via feed made from
rendered material from infected cattle or
sheep, a process which has been banned
since 1988.
There has never been a reported case of
disease following occupational exposure
(despite more than 184 600 cases in cattle
in the UK), however it remains a theoretical
risk. It is thought the most
likely route of occupational
infection would be via broken
skin and it is thought unlikely that the di
sease would be transmitted via aerosols.
There is no evidence of spread from person
to person, but this remains theoretically
possible.
Occupations and processes where vCJD may present a risk
Occupational exposure to vCJD
may occur in those who:

are in contact with infected animals; or

work with materials or products from in
fected animals, in particular brain,
spinal cord and lymphatic tissue

http://www.hse.gov.uk/ag...oses-data-sheets/cjd.pdf

http://www.nhs.uk/Condit.../Pages/Introduction.aspx

http://www.patient.co.uk...irosis-and-weils-disease

https://www.gov.uk/gover...ist-of-zoonotic-diseases

The lymphatic system exists in other areas besides the head, the head containing, obviously, less than the rest of the carcass.

two aspects from what I can gather; 1) direct contact with the saw 2) contact with animal product coming off the saw.
I'll leave the guarding to yourself, as hard to comment without seeing in situ.
As far as the "spatter" goes I would think about using a full face visor. This would cover and protect both the eyes and mouth/nose etc. Small piece of bone in the eye hurts. Remember though that vision will be obscured fairly quickly, particularly with fat smearing, so may need to provide some wipes etc to clean nearby for operatives.

Kurdziel, yes of course I should take note of any publications on this subject and at least make client aware. Must learn from the BSE episode and what led to it.
James, yes a full face visor seems appropriate, I'll have to observe further if Rpe needed

…”Viruses are a possibility, but not significant…”
How do you know viruses are not an issue? The problem with environmental microbiology is the tendency to focus attention on easy to culture organisms like the aforementioned enterobacteria and coliforms or even worse “indicator species”, which may(but may not) demonstrate the presence of really nasty bugs. The real problem with this is that we do not know what organisms are present on any carcass; we can only make an educated guess. Hopefully in the future using molecular techniques we might have a way to quickly scan for whatever is there but that is currently in the realm of the ‘Star Trek tricorder.’
So a risk might exist and so based on current knowledge some action needs to be taken with risk identified and managed. It could be as simple as using respirators, with a suitable protection factor, but you have to include it in the risk assessment.