Converting ETO Residual Limits from PPM to mg

Nash27

Involved In Discussions
Hi Could someone help me converting ETO residual limits from PPM to mg please. Our overseas contract manufacturer (CM) utilises IS10150 (Indian Standard) that provides EO, ECH, EG limits in PPM. Where as ISO 10993-7: 2008 list the quantities in mg. Our CM states that Indian standard is more stringent and listed below rationale;

EO ECH EG
AS PER IS 10150 PPM 25 25 250



AS PER ISO 10993-7 MG 60 60 NA
EXTRACT 5 ML 12 12
0.1 % MG 1.2 1.2
MCG 1200 1200
PPM 1200 1200

i.e. the Indian standard far more stringent than ISO10993-7: 2008. However, I am unable to understand the logic. The questioned device is class IIa simple IV set that come in contact with patient for Prolonged Exposure (>24 hours to <30 days) hence the ISO 10993-7: 2008 limit taken as 60mg.

Any help would be much appreciated. Thanks
 
Last edited:

planB

Super Moderator
Re: ETO Residual PPM vs mg

Nash27,

the limits listed in ISO 10993-7:2008, section 4.3 (and specifically section 4.3.3 for your classification) are absolute masses per device and applicable time period.

Values in ppm, i.e. parts per million, are ratios, and are 1-dimensional,such as mass per mass or volume per volume or sometimes more losely mass/volume.

Moreover, googling for "IS 10250" seems to return a standard applicable for the automotive industry, not for medical devices.

I would strongly recommend sticking to ISO 10993-7, which is applicable for medical devices. At least on an international level, you will have a hard time defending not complying to this standard.

And note that _all_ of these limits apply to a prolonged exposure device:

4.3.3 Prolonged exposure devices
The average daily dose of EO to patient shall not exceed 2 mg/d. In addition, the maximum EO dose shall
not exceed:
⎯ 4 mg in the first 24 h;
⎯ 60 mg in the first 30 d.
The average daily dose of ECH to patient shall not exceed 2 mg/d. In addition, the maximum ECH dose
shall not exceed:
⎯ 9 mg in the first 24 h;
⎯ 60 mg in the first 30 d.

4.3.5.2 Tolerable contact limit for EO
Either the EO TCL for surface contacting devices and implants shall not exceed 10 μg/cm2 or it shall
exhibit negligible irritation as specified in ISO 10993-10.
4.3.5.3 Tolerable contact limit for ECH for surface contacting devices
Either the ECH TCL for surface contacting devices and implants shall not exceed 5 mg/cm2 or it shall
exhibit negligible irritation as specified in ISO 10993-10.

HTH,
 

Nash27

Involved In Discussions
Re: ETO Residual PPM vs mg

Dear HHT,

My apologies the standard I have quoted is IS10150: 1981 (reaffirmed 1996) see attached. I am referring to the table 4 of the section Appendix B-5. I have attached the same standard here


(Deleted)

I hope this might help to review my query again. Thanks
 
Last edited by a moderator:

planB

Super Moderator
Nash27,

IS10150:1981, App. B-5, table 4 only list one single requirement for EO and ECH, respectively. Thus, this standard cannot be more stringent than ISO10993-7:2008, which lists multiple requirements for limits (see my first posting).

Moreover, I think IS10150:1981 is not state-of-the-art anymore. Similar sterilization-related ISO standards have undergone multiple revisions in the past 35 years (i.e. the age of this Indian standard).

ISO 11135:2014 and ISO 10993-7:2008 (the latter being currently amended) are the standards that are internationally regarded as state of the art.

HTH,

Gerhard
 

Nash27

Involved In Discussions
Dear Gerhard,

Pity on me for not extrapolating HHT ..is happy to help..I remember a joke, during the university studies we were trying to help one of our friends to buy a second hand car..going through the car advertisement he found a car within his budget... he said he is going to call, so we said ok go on.. he called and asked 'Hi, can I talk with Datsun'...there was a pause from other end ..and came reply.. mate do you want to talk with me or my car... I am selling my car which is a Datsun brand...we laughed as he was unaware, that the Datsun is a car....

I will remember HHT is not a name.

We have worked around the requirements, as our CM complies with requirements of ISO 11135 and ISO 10993-7 with an exception of the results mentioned in format that complies to IS standard. The EO extraction method, chromatogarphic analysis meets (performed by Lab) the ISO10993-7 requirements. I just needed to show the result relevance which I have got now.

Thanks for your help.
 

planB

Super Moderator
Nash27,

no problem. Make sure that the lab report states compliance to ISO 10993-7 for the used analysis method. And best of all, the lab would be accredited for this type of analysis. Then you will have an easier time defending the validity of your test results.

HTH (= hope this helps ;) ),

Gerhard
 
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