Hazards vs. Hazardous Situation Confusion

O

ortho_engineer

#1
Hello, everyone.... I have a question concerning differentiating hazards from root causes and/or hazardous situations… It seems like such a simple concept, but I find myself being incredibly indecisive about it.

I guess what I am having a hard time understanding is deciding on what level the hazards should be defined at. For instance I have a very simple example that for some reason I cannot wrap my mind around: if a nitinol guide wire, which is to pass through an implant to make sure it is centered properly (user need), has a design input of “Guide wire outer diameter to be .XXX” +/- .XXX,” then what would the hazards be only in relation to failure/fracture? The following are a few approaches I have come up with in my attempt to pretty much just say “the thing can break, and breaking is bad”:

“Mid-Level”
(1)
Hazard: Fracture
Events Leading to Hazard: Inadequate strength, Excessive (user input) energy, inadequate material properties, poor design control, etc.
Hazardous Situation: Contamination of operative site with foreign debris, deterioration or loss of device function (unguided implant placement), increased intraoperative time, etc
Harm: Tissue damage, revision surgery, etc

OR

Low-Level
(2)(a)
Hazard: Inadequate device strength
Events Leading to Hazard: Incorrect material due to insufficient design specifications, Inadequate inner diameter size due to uncontrolled manufacturing process, etc
Hazardous Situation: deterioration or loss of device function (unguided implant placement), fracture, contamination of operative site with foreign debris, etc
Harm: Tissue damage, revision surgery, etc

And

(2)(b)
Hazard: Excessive (user input) energy
Events Leading to Hazard: Inadequate factor of safety, untrained physician, etc
Hazardous Situation: deterioration or loss of device function (unguided implant placement), fracture, contamination of operative site with foreign debris, etc
Harm: Tissue damage, revision surgery, etc

And

(2)(c)
Hazard: Inadequate material properties
Events Leading to Hazard: uncontrolled process, new material selection, insufficient design control, etc
Hazardous Situation: deterioration or loss of device function (unguided implant placement), fracture, contamination of operative site with foreign debris, etc
Harm: Tissue damage, revision surgery, etc

OR

“High-Level”
(3)(a)
Hazard: Contamination of operative site with foreign debris
Events Leading to Hazard: fracture caused by incorrect material choice, fracture caused by inadequate inner diameter size, etc
Hazardous Situation: increased intraoperative time, increased friction in joint, adverse tissue reaction, etc
Harm: tissue damage, revision surgery, infection, etc

And

(3)(b)
Hazard: loss/deterioration of function: implants are unguided
Events Leading to Hazard: fracture caused by incorrect material choice, fracture caused by inadequate inner diameter size, etc
Hazardous Situation: increased intraoperative time, increased joint stresses, etc
Harm: tissue damage, revision surgery, infection, etc
---

I could go on, and that is just for the hazard relating to the device failing/fracturing…. I believe another hazard exists that relates to the interface mating condition between the guide wire and the implant, and I have the same problem with that as I do with what you just read above (is “insufficient mating clearance with implant” the hazard, or is “oversized outer diameter” the hazard, or is “unguided implant” the hazard, etc?)

Thanks for any advice you can offer, and sorry for the long point – I am just so far past the point of over-thinking this whole hazards-thing that I am at a complete loss haha.

Take care,
K
 
Elsmar Forum Sponsor

yodon

Staff member
Super Moderator
#3
Well, I'll take a shot...

What struck me was the repeated use of "..., etc." - especially in events / situations descriptions. I think you want to narrow down to "this is what could happen" and "this is how we control it / prevent it from happening." For example, if the wire breaks because of excessive force, you can control it (mitigations) through stronger wire, user training, and/or some force detection / limitation mechanism (quite possibly up to all of the methods identified).

The goal is to get to those controls and when you have a laundry list, it's hard to focus on what to do.

It looks like you've done a good job of thinking it through, maybe just take a "rifle" approach rather than a "shotgun" each time.
 
S

sjared

#4
I continually struggle with this concept as well. One method that has helped me because I am more of a visual person is to construct a fault tree. I don't get too sophisticated with adding probabilities for various failure modes and such, but I just concentrate on mapping out the interactions. I usually just start on a white board where I can easily add/erase stuff.
 

Steve Prevette

Deming Disciple
Staff member
Super Moderator
#5
I'm not medical, but am an engineer (and no, did not stay at a certain hotel chain last night),

But seems to me you need to look at - what is the function that the guide wire performs. And what happens to the patient if that function is not performed.

You said the wire is to be sure the implant is "centered properly" - so what if it is not?

Then what sort of failures could occur to prevent the wire from functioning?

And then are there ancillary effects if something completely different happens (you mentioned if the wire breaks, then this because a foreign body in the patients body).

I'd work backwards from what is the desired function, to what happens if the function doesn't function, to what can prevent the part from doing the function. Then there are side effects.
 

v9991

Trusted Information Resource
#6
in the meanwhile experts come down with more simplified&crisp answer, let me try to clarify through the tool/concept(FMEA), which i am more familiar with...

I have adopted the following approach towards resolving the confusion... ( i have narrated the following using the FMEA terminologies; i believe same can extended to the terminologies pertaining to hazard )

in below example, let me try to relate to your problem description...
hazard(including 'harm') is effect; (hazard and harm i believe they only differentiate the product functionality and effect of non-functionality(dis-functionality) on end user or intended use)
hazardous situation...failure mode
events leading to hazard...root cause

1st characteriza the product wrt following.
*) target product profile(TPP) (expectations of performance from patient, regulatory market etc,)
**) (critical) quality attributes(CQA) (means through which the quality is monitored)
***) (critical)material attributes and process parameters(CMA & CPP) ( means through which the process is controlled)

now coming down to performing risk assessment (hazard vs hazardous situation)
at design fmea stage...
I would consider the hazards of product-failures which could be encountered to affect target product profile.
and here, the 'root causes'could be attributed to ''design and process selected' (i.e., that would lead to narrowing down or exclusion criteria of process & design of product; )
of course, we could also trace the 'root causes' to material and process parameters. (as far as possible)

at design stage,
you would consider the target product profile not being met as failure mode i.e.,
2(a)
(hazard and hazardous situation)failure mode : 'inadequate device strength' (here its implied CQA)
(harm)effect : patient effect, loss of labeled functionality of device etc.,
(events leading to hazard)causes...material, device-design (mfg process, process parameters etc.,)
current controls and action plan :- would describe details specific/relevant to each pertinent cause mentioned separately in individual rows.



similarly at process fmea...
we will consider the hazards of process-failures which could be encountered during manufacturing to affect the TPP & CQAs;
and here, the root causes could be attributed to CMA & CPPs. (i.e., that would lead to optimization/finalization of cma and cpp)
and actually result into a control plan to be implemented at manufacturing process (commercial batches)

+) also above approach makes sense, because all the ''current-controls& action-plan'' (FMEA columns) are towards either controlling/monitoring the root-cause attributes; also sometimes, it could also eliminate the failure modes through product/process design; hence, its relevant to have those attributes in root-cause categories as mentioned above.
++)now that''s a thumb rule, i have tried to explain the certain exceptions/alternatives, however taking above approach would provide a guidance towards completeness and effectiveness risk assessment.

note :- although the attachment enclosed is of generic nature, but provides a pretty much step by step process of leading through above steps...
Section 3 - THE HAZARD ANALYSIS AND CRITICAL CONTROL POINT (HACCP) SYSTEM 6 list all potential hazards associated with each step, conduct a hazar
Table of Contents

http ://www .faa .gov/library/manuals/aviation/risk_management/ss_handbook/media/Chap7_1200.pdf - OBSOLETE BROKEN 404 LINK(s) UNLINKED

hope this is relevant and helps for your context...


Remarks...
Hazard: gas cylinder, knife
Harm: threats of burns/explosion, cuts...
Hazardous Situation: unsafe fire./heating stations, or no fire hydrants etc.,, and no gaurds/safety sheets for sharp knifes etc.,
Events Leading to Hazard: unsafe design(lack of infrastructure...procedures) or unsafe act(ignorance / lack of attention)
 

Attachments

Last edited by a moderator:
O

ortho_engineer

#7
Thanks for the responses, they were all very appreciated!

It looks like you all mentioned it in some way, particularly Yodon and Steve Prevette, but what resonated with me the most were the responses to work backwards and make the control method the goal of the exercise… Perhaps it will be beneficial to reframe my approach by focusing less on breaking down hazards into discrete occurrences (it can fracture because of this, or it can fracture because of that), and more on finding/defining the control methods (this is how I stop it from fracturing this way, and this is how I stop it from fracturing that way).

So it got me thinking, as an engineer I do not implement measures to control foreign debris (in this specific case) – the control measures I implement (material-related, energy-related, strength-related) are done so to control fracturing… So Fracturing = Hazard, Foreign Debris = A Hazardous Situation, Material/Energy/Strength Related Activities = Risk Control Measures.

Anyway, thanks again for responding – I feel that if anything I am able to proceed forward more consistently than before.
 

Statistical Steven

Statistician
Staff member
Super Moderator
#8
Thanks for the responses, they were all very appreciated!

It looks like you all mentioned it in some way, particularly Yodon and Steve Prevette, but what resonated with me the most were the responses to work backwards and make the control method the goal of the exercise… Perhaps it will be beneficial to reframe my approach by focusing less on breaking down hazards into discrete occurrences (it can fracture because of this, or it can fracture because of that), and more on finding/defining the control methods (this is how I stop it from fracturing this way, and this is how I stop it from fracturing that way).

So it got me thinking, as an engineer I do not implement measures to control foreign debris (in this specific case) – the control measures I implement (material-related, energy-related, strength-related) are done so to control fracturing… So Fracturing = Hazard, Foreign Debris = A Hazardous Situation, Material/Energy/Strength Related Activities = Risk Control Measures.

Anyway, thanks again for responding – I feel that if anything I am able to proceed forward more consistently than before.
An easy way to look at it....the hazard is fracture. The hazardous situation is what occurs to patient/user/device if the hazard occurs.
 

Marcelo

Inactive Registered Visitor
#9
Hazards are potential source of harm, per the definition.

For the hazard to become a hazardous situation, an exposure has to occur (P1). There's a combination or sequence of events that exposes the patient/user/environment to the hazard and then creates the hazardous situation. Sequence or combinations of events should be actions and events, not generic comments. Why is it important? Because generally you need to act on the sequence of events to lower the risk.

This can be seen in Figure E.1 of the standard. It's very important that this figure is created for each hazardous situation. My experience shows that users rely too much on techniques, such as FMEA, which do not provide all the information required, and this is part of the problems.

The best sugeestion for categorizing hazards (which is really not required but facilitates the implementation of ISo 14971) is found in table E.1 of the standard - energy hazards, biological hazards, physical hazards,operational hazards, etc, each with possible sub-hazards.

Failures are not hazards nor hazardous situations. Failures are part of the sequence of events which exposes the hazards and creates the hazardous situations.


Example:

Hazard: Functional (excessive output)

Sequence of events:
1 - user sets rotating output control with excessive strenght (X torque)
2 - rotating output control breaks (failure as p[art of the sequence of events)
3 - output control is lost

P1 is made of a conjunction of the probabilities for each part of the sequence of events.

Hazardous situations: Patient under excessive output from device (please note the link with the hazard - the hazard is potential, but the hazardous situation is a situation on which the user was exposed to the hazard - just as in the definition).

P2 is the probability of the hazardous situation leading to a harm. Please note ein the example that the hazardous situation is defined as excessive output. There's a probability that the failure of control leads to this.

In this case, let's say the severity of the harm would be burns.

The probability of ocurrence of the hard would be related to P1 and P2, for example, P1 x P2


You would need to add another hazardous situations, for example, the case where the failure lead to insufficient output.

Please note that in this case the sequence of events would be the same, but the hazard and hazardous situation, and harm, and (probably) the probability of ocurrence of harm, would be different:

Hazard: Functional (loss of function)

Sequence of events:
1 - user sets rotating output control with excessive strenght (X torque)
2 - rotating output control breaks due to strenght (failure)
3 - output control is lost

Hazardous situations: Device does not output and patient is not treated or thinks is treated


For both, note that the risk control options could be different.
 
Last edited:

v9991

Trusted Information Resource
#10
My experience shows that users rely too much on techniques, such as FMEA, which do not provide all the information required, and this is part of the problems.
i agree with the point; this is mainly because of,relying mainly/alone a single tool. & what we have done is to, before initiating FMEA ---> made it mandatory to have a process-mapping; identification of critical quality-material-process parameters (with rationale & justification)

so, that has solved the limitation to quite an extent; but then of course i did add additional steps to the FMEA process. ( this was also relevant, as we also need to consider to rolling the process out at multiple locations/units - teams etc.,)

The best sugeestion for categorizing hazards (which is really not required but facilitates the implementation of ISo 14971) is found in table E.1 of the standard - energy hazards, biological hazards, physical hazards,operational hazards, etc, each with possible sub-hazards.
this aspect is met through adding a hazard category on the left hand side of FMEA table; also through including the criteria in the risk assessment/evaluation step.


Failures are not hazards nor hazardous situations. Failures are part of the sequence of events which exposes the hazards and creates the hazardous situations.
agreed...i was trying to capture the same when i said in my earlier response...
...(hazard and hazardous situation)failure mode ...
 
Thread starter Similar threads Forum Replies Date
I Сorrespondence between hazards and risks ISO 14971 - Medical Device Risk Management 2
E Normal Condition Hazards in Risk Analysis ISO 14971 - Medical Device Risk Management 3
E PEMS Hazards - IEC 60601 Clause 14.6 - Internal data use - Pressure sensor IEC 60601 - Medical Electrical Equipment Safety Standards Series 3
T How do you define your Hazards? <a Risk Management discussion> ISO 14971 - Medical Device Risk Management 16
K Identification of hazards and Risk file IEC 62366 - Medical Device Usability Engineering 7
M Identifying Hazards - Risk management process ISO 14971 - Medical Device Risk Management 6
M Medical Device News ECRI – 2019 Top 10 Health Technology Hazards Medical Device and FDA Regulations and Standards News 0
D Hazard analysis for our medical device - Hazards seem to overlap 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 1
D Product Safety in AS9100D Clause 8.1.3 - Hazards Analysis AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 18
M ECRI Top 10 Health Technology Hazards for 2017 Other Medical Device and Orthopedic Related Topics 3
Jen Kirley How to evaluate hazards in using bar code scanners in chemical manufacturing Occupational Health & Safety Management Standards 1
D Different kinds of Risk Analysis for various Hazards ISO 14971 - Medical Device Risk Management 3
M Control Measures for Hazards already deemed Low Risk ISO 14971 - Medical Device Risk Management 6
C Hazards of Old Electronics Quality Manager and Management Related Issues 9
E Harms Severity Scoring - Combination of Hazards ISO 14971 - Medical Device Risk Management 4
C List of Potential Hazards Definitions in Annex E of BS EN ISO 14971:2009 ISO 14971 - Medical Device Risk Management 4
P ESD and Bio-Hazards in a Medical Equipment Repair/Maintenance Facility Manufacturing and Related Processes 2
S Refinery Cold Weather Hazards! Manufacturing and Related Processes 0
S Should Identified Hazards and Risks necessarily have Linkage with Legal Requirements? Occupational Health & Safety Management Standards 8
K Do you have to use RPN in Medical Device Risk Analysis? Identification of Hazards ISO 14971 - Medical Device Risk Management 6
S Do Environmental 'Aspects' and 'Hazards' express the same idea? Occupational Health & Safety Management Standards 5
S Should the hazards with negligible risks be documented and/or reviewed? Occupational Health & Safety Management Standards 11
Sidney Vianna ISO/TS 22002-1:2009 gives food manufacturers new tool to control hazards Food Safety - ISO 22000, HACCP (21 CFR 120) 0
C HACCP in Egg Production - Controlling hazards at the farm level Food Safety - ISO 22000, HACCP (21 CFR 120) 6
E ISO14971 - Determination of possible hazards (SU, UU, PC) ISO 14971 - Medical Device Risk Management 3
K Should we rate according to the prob. a risk will occur or that risk causes hazards? ISO 14971 - Medical Device Risk Management 5
F Oxygen Concentrator Hazards ISO 13485:2016 - Medical Device Quality Management Systems 9
M PFMEA Detection Rating for Operator Hazards FMEA and Control Plans 5
H Safety Hazards Finding and Recommendation Report - Seeking Format Examples Various Other Specifications, Standards, and related Requirements 0
S Painting on Floor of Machine Shop - What Aspects/Impacts and Hazards to consider? Miscellaneous Environmental Standards and EMS Related Discussions 10
T When is a hazardous situation? ISO 14971 - Medical Device Risk Management 34
T Documenting hazardous situations associated with user/patient population ISO 14971 - Medical Device Risk Management 3
K Contains hazardous substance symbol EU Medical Device Regulations 1
6 Management of SDS and Hazardous Material Occupational Health & Safety Management Standards 2
L Hazardous Waste - Tips for creating standardized training Miscellaneous Environmental Standards and EMS Related Discussions 2
MrTetris Informational Risk Register - Same hazardous situation, different severity of harms ISO 14971 - Medical Device Risk Management 7
B Interpreting "misuse" when assessing Hazardous Situations ISO 14971 - Medical Device Risk Management 2
A Hazardous material storage shed flooring material Miscellaneous Environmental Standards and EMS Related Discussions 6
somashekar Applying legal requirements in hazardous waste management. Miscellaneous Environmental Standards and EMS Related Discussions 1
A Is Risk Management Process compliant to ISO 14971 in absence of Hazardous Situations? ISO 14971 - Medical Device Risk Management 5
C Hazardous Good Packaging Labeling for Airfreight EU EASA and JAA Aviation Standards and Requirements 2
R Loading Capacity of Hazardous Lithium Batteries IEC 60601 - Medical Electrical Equipment Safety Standards Series 1
C Example of Hazardous Situation Report Funny Stuff - Jokes and Humour 1
M MDD 93/42/EEC, Annex IX - Class IIa vs IIb: "Potentially Hazardous" definition EU Medical Device Regulations 2
B Are Medical Equipment repair cleaning materials hazardous waste? Other Medical Device and Orthopedic Related Topics 2
somashekar Hazardous Waste: Is this an appropriate interpretation Miscellaneous Environmental Standards and EMS Related Discussions 1
G Specific location where Hazardous Waste Labels need to be placed RoHS, REACH, ELV, IMDS and Restricted Substances 2
B RoHS (Restriction of Hazardous Substances) - Can somebody guide me? RoHS, REACH, ELV, IMDS and Restricted Substances 7
H Hazardous Chemicals Specified in MSDS (format of MSDS) Occupational Health & Safety Management Standards 10
G Hazardous Waste Consignment Note - Please Help Miscellaneous Environmental Standards and EMS Related Discussions 2

Similar threads

Top Bottom