Tiêu chuẩn iso 11138 5 2017

© ISO 2017 Sterilization of health care products — Biological indicators — Part 5 Biological indicators for low temperature steam and formaldehyde sterilization processes Stérilisation des produits de[.]

Sterilization ofhealth car e products —

Part 5:

Biolog ical indicators for

Stérilisation de s produits de santé — Indicateurs biolo iques —

Partie 5: Indicateurs biolo iques p ur la stérilisation à la v peur

d’ea et a frmaldé yde à b sse temp ratur

S con edition

2 17-0

COPYRIGHT PROTECTED DOCUMENT

© ISO 2017, P blshed in Sw itz rlan

A ll rig hts r eserved Unles otherw ise spe ified, nopar of this p blc tion ma y be r epr od c d or utilz d otherw ise in an form

or b an me ns, ele tr onic or me hanic l, inclu in p oto opying , or postin on the internet or an intranet , w ithout prior

written permis ion Permis ion c n be req esed from either ISO at the ad r es below or ISO’s member bod y in the c u try of

the r eq eser

ISO c pyrig ht ofic

C de Blan on et 8 • C 4 1

CH-1 14 Vernier, Geneva, Switzerlan

Tel + 12 7 9 011

Fax 412 7 9 0 4

c pyrig ht@iso.or g

www.iso.or g

F reword i v

Introduction v

1 Sc ope 1

2 Nor mati ve r eferenc es 1

3 Terms an definitions 1

4 General r equirements 1

5 Test or ganism 2

6 Suspensio 2

7 Car rie and pr imar y packag ing 2

8 Inoculated car rier s and biolog ical indicator 2

9 Po ulation and r esistanc e 2

A nne x A (normative) Meth d for deter minatio of resistanc e to low-temperatur e ste m and formaldeh yde 4

A nne x B (informative)Ratio ale for the lquid-phase test method for low-temperature ste m and formaldeh yde biolog ical indicator 6

Biblog raphy 7

ISO (he Int ernational Org nization for Stan ardization) is a worldwidefede ation of national s an ards

b dies (ISO membe b dies) The work of pr p ring Int ernational Stan ards is normaly car ied out

through ISO t ech ical committ ees Each membe b dy int er st ed in a subje t for w hich a t ech ical

committ ee has be n es a lshed has the right t o be r pr sent ed on that committ ee Int ernational

org nizations, g ove nmental an non-g ove nmental, in laison with ISO, also take part in the work

ISO cola orat es closely with the Int ernational Ele trot ech ical C mmis ion (IEC) on al matt ers of

ele trot ech ical s an ardization

The proc d r s used t o develo this document an those int en ed for it furthe maint enanc ar

desc ibed in the ISO/IEC Dir ctives, Part 1 In p rticular the dife ent a pro al c it eria ne ded for the

dife ent ty es of ISO document should be not ed This document was draft ed in ac ordanc with the

edit orial rules of the ISO/IEC Dir ctives, Part 2 ( e www iso org dir ctives)

A tt ention is drawn t o the p s ibi ity that some of the element of this document ma be the subje t of

p t ent right ISO shal not be held r sponsible for identifying any or al such p t ent right Detais of

any p t ent right identified d ring the develo ment of the document wi be in the Introd ction an / r

on the ISO ls of p t ent de larations r c ived ( e www iso org p t ent )

Any trade name used in this document is information given for the convenienc of use s an does not

cons itut e an en orsement

F or an ex lanation on the v lu tary natur of s an ards, the meaning of ISO spe if ic t erms an

ex r s ions r lat ed t o conformity as es ment, as wel as information a out ISO’ s adhe enc t o the

World Trade Org nization (WTO) principles in the Te hnical Bar ie s t o Trade (TBT) se the folowing

URL: www iso org iso / for word html

This document was pr p r d b Te h ical Committ ee ISO/TC 1 8, Ste ii zation o health c ar produc ts

This se on edition canc ls an r plac s the f irs edition (ISO 1 1 8-5:2 0 ), w hich has be n

t ech icaly r vised

A l s of al p rt of ISO 1 1 8 can be foun on the ISO websit e

ISO 1 1 8-1 spe if ies prod ction, la el ing, t es methods an pe formanc r q ir ment for the

man factur of biolo ical in icat ors inclu ing inoculat ed car ie s an suspensions int ended for use

in v ldation an monit oring st eri ization proc s es This document gives spe ific r q ir ment for

those biolo ical in icat ors int en ed for use in low-t empe atur st eam an formaldehyde st eri ization

proc s es

An ex B gives rationale for the lq id-phase t es method for low-t empe atur st eam an formaldehyde

biolo ical indicat ors

The ISO 1 1 8 se ies r pr sent the cur ent “ tat e-of-the-art” ac ording t o the ex e t r pr senting

man factur rs, use s an r gulat ory a uthorities involved in develo ing the s andard The int ent is

not t o promot e the use of biolo ical in icat ors w he e such use is not advised, but t o pro ide common

r q ir ment for the prod ction of those biolo ical in icat ors that ar known t o be in use t oda

A s an ard exis s pro iding g ene al r q ir ment for the v ldation an control of low-t empe atur

st eam an formaldehyde st eri zation proc s es ( e ISO 2 424 )

NOTE It is pos ible that some cou tries or re ions have p blished other stan ards covering req irements

for st erilization or biolo ical in icat or

A dvic on sele tion, use an int erpr tation of r sult w hen using biolo ical in icat ors can be fou d in

ISO 1416 1

Sterilization ofhealth car e products — Biolog ical

Part 5:

This document spe ifies r q ir ment for t es org nisms, suspensions, inoculat ed car ie s, biolo ical

in icat ors an t es methods int en ed for use in as es ing the pe formanc of st eri zation proc s es

emplo ing low-t empe atur st eam an formaldehydeas the st eri zing ag ent

NOTE 1 R eq irements for validation an control of low-temperature ste m an formaldehyde sterilization

proces es are provided by ISO 149 7

NOTE 2 R eq irements for work place safety can b provided by national or re ional re ulations

2 Normati ve r eferences

The folowing document ar r fe r d t o in the t ext in such a wa that some or al of their cont ent

cons itut es r q ir ment of this document F or dat ed r fe enc s, only the edition cit ed a ples F or

un at ed r fe enc s, the lat es edition of the r fe enc d document ( inclu ing any amen ment ) a ples

ISO 1 1 8-1:2 1 , Sterili zatio o health c ar produc ts — B iolo ic al indic ators — Part 1: G ene al

r q ir ments

3 Terms and definitions

For the purp ses of this document, the t erms an definitions given in ISO 1 1 8-1 an the folowing a ply

ISO an IEC maintain t erminolo ical data ases for use in s an ardization at the folowing ad r s es:

— IECEle tro edia: a aia le at ht p:/ www ele tro edia org

— ISO Onlne brow sing plat orm:a ai a le at ht ps:/ www iso org o p/

3.1

low-temperature steam and formaldehy e steriizatio

proc s incorporating for ed air r mo al, w hich alow s ex osur of wra ped g oods t o st eam at

sub-atmosphe ic pr s ur , and th s at t empe atur s les than 1 0 °C, with the admis ion of formaldehyde

g s, keeping the st eri izing ag ent in a st eady s at e throughout the hold time

4 General r equir ements

The r q ir ment of ISO 1 1 8-1 a ply

5 Test or ganism

5.1 The tes or ganisms shal be sp r es of G eo ac illus stearothe mo hilus or othe strains of

microor ganisms of demons rated eq iv lent pe formanc as r eq ir ed b this document

NOTE 1 B ac ilus s te r th rmo hius has b en reclas if ied as G eo ac ilus te r th rmo hius

NOTE 2 G eo ac ilus s e r th rmo hius NCIB 8 24, DSM 6 9 , AT C 79 3, AT C 1 149 an AT C 1 9 0 have

b en fou d to b suita le

1)

5.2 If a tes or ganism othe than Geo acillus stearothe mo hilus is used, the suita i ty of the r esis anc

of that tes or ganism shal be dete mined

The r q ir ment of ISO 1 1 8-1 a ply

7 Car ier and primary packag ing

7.1 The suitabi ty of the car ie and primary p ckag ing mate ials for biolog ical indicators for use in

low-temperatur e s eam an formaldehyde s e i zation proc s es shal be demons rated in ac or danc

with the r eq ir ements of ISO 1 1 8-1:2 1 , 5.2 and A nnex B

NOTE Car ier b sed on f ilter paper might not b suita le b cause of the chemisorption of formaldehyde on

cel ulose surfaces

7.2 The ex posur e con itions to dete mine complanc shal be the folowing :

a) minimum ex osur t empe atur : gr at er than or eq al t o 5 °C a ove the man factur r’ s s at ed

ma imum ex osur t empe atur ;

b) ma imum ex osur t empe atur : as s at ed b theman factur r; if not s at ed b the man factur r,

thema imum ex osur t empe atur shal be gr at er than or eq al t o 1 0 °C;

c) ex osur time: gr at er than or eq al t o 1 0 min

NOTE T ese con itions have b en selected t o represent a re listic chal eng t o the car ier while remaining

within the practical limits of a low-t emperature ste m an formaldehyde st erilization proces

8 Inoculated car iers and biolog ical indicators

The r q ir ment of ISO 1 1 8-1 a ply

9 P opulation and r esistance

9.1 The r esistanc char acte is ics shal be s ated ac ording to ISO 1 1 8-1:2 1 , 6.4

9.2 The via le cou t shal be stated with incr ement les than or eq al to 0,1× 10

n

pe u it (e.g pe ml

of suspension, pe inoculated car ie or pe biolog ical in icator)

9.3 For inoculated car ier s an biolog ical in icators, the via le cou t shal be g r eate than or eq al to

1,0 × 10

5

1) T ese ar e examples of suita le pr od cts a vaila le commer cialy T is information is g iven for the con enience

of user of this document an do s not constitute an en or ement by ISO of these pr od cts

9.4 The r esistanc shal be ex r es ed as the D v lue in mins at 60 °C The D v lue of each b tch/lot of

biolog ical in icators or inoculated car ie s shal be s ated in min tes to one de imal plac at 6 °C

9.5 Suspensions, inoculated car ie s or biolog ical in icators containing G eo ac illus stearothe mo hilus

spores shal ha ve a D

60

v lue of g r eate than or eq al to 6 min when tes ed ac or ding to the con itions in

A nnex A Othe micr oor ganisms shal ha ve D v lues sup orting thea plcation

9.6 The r esistanc char acte is ics spe ified in this document an any othe p rt of ISO 1 1 8 shal be

defined using the spe ific c itical v ria les as ociated with ther efer enc d s e i zation proc s

9.7 D v lues ar e dete mined ac ording to methodsg iven in ISO 1 1 8-1:2 1 , A nnexes C an D

9.8 Dete mination of D v lue an surviv l-ki r esp nse characte is ics ar e b sed on the pr oc s

p ramete s in A nnex A

9.9 The surviv l-ki win ow should be calculated using the formulaein ISO 1 1 8-1:2 17, A nnex E

NOTE T is information can b of value to the user when comparing diferent b tches from the same

man facturer

E AMP E Using the formula in ISO 1 1 8-1:2 17, An e E, with the minimum pop lation an minimum D

value req irements specif ied in this document, the survival-kil response charact eristic are

— at 60°C: survival time gre ter than or eq al to 1 min an kil time les than or eq al t o 54 min

A nnex A

(normative)

A 1 Principle

This method is b sed on a q altative t es on inoculat ed car ie s imme sed in an aq eous solution of

formaldehyde This method has be n shown t o pro ide mor r prod cible r sult than using a v p ur

phase, chambe method

Spe if ic r q ir ment r lat ed t o the t es method ar pro ided in A.3

A 2 Inoculated car ier ex posure c onditions

A 2.1 T e tes sys em consis s of tes tubes fi ed w ith 1 ml of aq eous solution of formaldehyde

and held in an automaticaly contr oled temper atur e wate b th The tes sys em shal be ca a le of

maintaining the con itions spe ified for ex posure pe iods betwe n 1 min an 1 0 min to an ac uracy

of ± 0 s

A 2.2 T e formaldehyde conc ntr ation of the aq eous solution shal be dete mined b use of analytical

chemical methods

A 2.3 T e method shal be v ldated

A 3 Proc edure

A 3.1 Use an aseptic te h iq e when pe forming this tes in or de to pr event ad ventitious

contamination

A 3.2 C mpletely imme se the inoculated car ie s in the tes tubes fi ed with the formaldehyde

solution at a conc ntr ation of 1 mol/l ±0,0 mol/l that has be n pr e-heated to 6 °C± 0,5 °C

A 3.3 E sur e that the inoculated car ie s ar e completely imme sed in the formaldehyde solution an

do not lo t to the surfac

A 3.4 At the end of the spe ified ex posur e time, remo e the inoculated car ie s from the formaldehyde

solution

A 3.5 Elminate the exc s lq id an imme se the car ie s in the tes tubes fi ed with a fiter ed solution

of 2 % Na

2

SO

3

for at leas 1 min at ambient con itions in orde to inactiv te formaldehyde resid es on

the car ie s Close the tes tubes

Car should be taken t o minimiz a itation in the formaldehyde, as wel asin theneutralz r solution t o

pr vent “wash of”of t es org nisms

NOTE Histidine an cyst eine have b en shown t o b efective neutralization a ents

A 3.6 T e g r owth medium shal bespe ified an q alfied to ensur e reco e y of the tes or ganisms.

NOTE S yb an casein dig st medium has b en fou d suita le for this t est

A 3.7 Transe the car ie s into tes tubes fi ed w ith 1 ml of the g rowth medium ac or ding to A 3.6

Close the tes tubes

A 3.8 Treat the tes tubes for 6 min at 9 °C for heat activ tion of the sp r es

A 3.9 At theen of the pr oc s , incub te the car ie s ( e ISO 1 1 8-1:2 1 , Clause 7)

A 4 Determination of resistance

R esis anc charact eris ics shal be det ermined ac ording t o methods given in ISO 1 1 8-1:2 1 ,

An ex es C, D an E

A nne x B

In orde t o t es in icat ors in a r prod cible man e , spe if ic t es eq ipment r sist omet ers) an methods

ar used F or the low-t empe atur st eam an formaldehyde proc s , it is extr mely difficult t o c eat e

a s a le formaldehyde g s conc ntration in a r sist omet er, sinc def ined amount of formaldehyde

inje t ed int o a ves el wi dis olve in the smal amount of wat er dro let (con ensat e) pr sent The

conc ntration of formaldehyde in this wat er is 1 0 0 times t o 1 00 times highe in conc ntration than

in the g sphase, depen ing on the t empe atur

[5]

It is for this r ason that this document uti z s a lq id-phase t es method w he e the formaldehyde

conc ntration is clearly defined an alow s r prod cible con itions

B.2 The low-temperature steam and formaldehyde proc es

Even with cons ant st eam conditions an s a le formaldehyde g s conc ntrations, the st eri ization

proc s depen s hea i y up n the design of the st eri iz r chambe an the natur of the lo d The

formaldehyde st eri ization proc s can be conside ed simpl s icaly in two st eps:

a) as in st eam st eri ization proc s es, an aq eous con ensat e film is c eat ed on the surfac ofthe lo d;

NOT 1 T is con ensation wil oc ur very rapidly

b) sinc the conc ntration of formaldehyde at eq i brium betwe n the g s and lq id phases is

extr mely dife ent (1:1 0 0 t o 1:1 00 ), the time taken for this eq i ibrium t o oc ur wi l be

r latively long

NOT 2 In practical situations, this can req ire a time frame from 1 min u t o 2 h

The lethalty of the st eri ization proc s th s depen s hea i y on the formaldehyde conc ntration in

the lq id phase, i.e surfac con ensat e It can be ve y diff icult t o det ermine in a solut e t erms the time

taken for these eq i ibrium con itions t o be achieved