I 4 PSD NUMBER'

E 11)

1 6-14 PROCESS SPECIFCATION PflOCESS SPEe NO,

BAC 5763

-- / _ _ ~ X . 4. Jr..dke

MAl'L d& &W&LL . . dcgreasicig aIuniinutn, steci, Iur

l i taniurri , magnesium, nickcl-based, cobalt-based allay ,,

- OEPARTURE O R l d S ~ h o l

7-26-91 REUS DATE

SUeCONTRACTOn(Sj AFFECTED ON MODELS I MFG DEPTS OF DIV BELOW AFFECTED

parts and clectro plated stcel parts.

ALL ALL COMMI5RCIAL AIRPLANES AM) RCAG AND SUPPORTING DERIVATIVES TI-iEREOP

1'IiIS PSD SUPERSEDES PSDS 6-11 AND 6-15

SCOl'E Revise to rciid ns rollows: This spccirication cslnl)lishcs the tcquiremcnts for immersion and spray cleaning/degreasing processes using etnulsion clcaners and degrcaser solutions.

CLASSWICATXON Revisc lo rend RS follows: a. q p c r Cienerat immersion niid spray clcaning using emulsion clcancrs. b. 'wpe I I Aqueous alkaline and solvcnileniulsion dcgreasing of aluminum, magnesiutn,

nickcl-bascd, cobalt-based, ferrous, and tilanium alloy parts and electroplated stccl exccpl for aluminum and titanium lioneycomb core or oxygen system parts. This is an option to lhe requirements of vapor degreasing in accordancc with IL4C 5408 or solvcrrt vapor cleaning in nccordnncc wilh'I'l'-C-490, Metilod rr. Anodized or dodincd par16 soiled or contaminmd shall not be cleaned using cmulsion dcgreascr malerials exccpl wlicri lhcse parts nrc to be completely rcproccsscd.

Aqueous dcgrcasing of parts can he complcted prior to ciiher clicmicul processing or other processes, for example, hciit lreatmcnt, machining UL- forming. Thcrc options ice designated BS Class 1 and Cl~ss 2. Class 1 - Ikgrcasing prior to chcmiciil iwocesning wlierc immediate drying is not rcquircd. Clas.; 2 - Gcncral &,greasing of {>arcs whcre drying is rcquircd.

PROCESS SPEC TITLE rso NUMBCR 6-14 PROCESS SPECIFICATION HMULSION CLEANING

DEPARTURE (IMMBIISION AND SPRAY)

2 CLASSIFICATION (Continued)

c. Within Clrsr 2, degrcasing a n be further classified according to Ihc parls potential to ciitrap solutiwi or type of platlng on piin. Grade A - Ikgreasing of parts wilh hying surfaces itndlor other surface8 that will cnlrap

Grade LI - Dcgrcasing of parts which will not cntrap solution and can be adequatcly rinsed. Grade C - Degreasiiq of clecfroplaicd ferrous alloys hat-treated ahovc 180 Ksi Ultimatc

pwtioos of the solutlon and c i n only \E rwnovcd with exhausiivc rinsing.

Tcnsilc Streligtll (UIS), except For nickel and chromium plated parts. For clcclroplnted ferroiis alloys heat-treated below 180 Ksi, and all nickcl and clirome plated pacts, refer to Grade A or Ciradc II 86 applicable.

3 REFERENCES

Add the following new Items: ASI'M F 519

ASTM I: 945 nAC 5008 Applicnlion of Lubricants BAC 5019 Chromic Acid Anodixing RAC 5034

l lAC 5408 Vapor Dcgrcasing I'IAC 5423 BAL' 5719 I1AC 5750 Solvcni Cleaning DAC 5753 l3AC 5804 BAC 5884 I M S 10-1 1

Mechanio?l Iiydrogcn P"ri(llcmcnt Testing of Plating Processes and Aircraft Mniiiteiiuncc Chemlcals Slress-Corrosion of Titanium Alloys by Aircraft Enginc Cleaning Matcrials

Tkmporary Protection of Production Materials, Rtrts and Asscmblics

l'cnctrnnt Methods of Inspection Chcmical Convcrsion Coatings for Aluminum and Alrkminum Alloys

Cicaning, Dcscxling and Stirlace Prcpara(ion of 'l'i(anium and'l'itanium Alloys L o w Iiydrogcn Embrittlcmenf Cadmium-Titanium Alloy Plating Anodizing of Aluminum Alloys

Clicniicul and Solvent Resistant Finish 7219 ln(ergrantrlar Attack, 'Iksf Mctliod

MIL-A-8625 Anodic Coatings for Aluminum and A l ~ ~ m i n u n i Alloys

~flOCESS SPEC NO.

UAC 5763

PROCESS SPEC l7Tl-f PSD NUMBER

6-14

PO 3 OF 12

PROCESS SPECIFICATION EMUIYlON CLEANING DEPARTURE (IMMERSION AND SPRAY)

5

7

8

8.1

8.1.X

n.1.y

PROCESS SPEC NO.

BAC 5763

MATERIALS CONTROL Add the following new ltcms: v.

w. Drulin BlSGD, Hrtilin Company

x.

y. P.

DEFINlTIONS Add the following ncw Items: Chemical Processing -The contact with any liquid or xdution other than pcnelranl

Dauwlcun 282, W. I<. Grace Company

Diogcnic SI2 373, Rochector-Midland Company Uiogcnlc SC 374, Rochester-Midland Company A-200. U. S. Polychcmicels Company

impection fluids irt awordance with BAC 5423, proteclivc agents in accordance with RAC 5034, organic solvents in accordancc with RAC 5750, and/or manuracturcd c001anls and lubricants in accordance willr lJAC 5008, with a mecal surface.

'Total Cumulative " n e - Thc time that the part scc6 the dcgreaser solution during a singlc continuous degrcasing sequcnce as opposed to all processing exposure for lha t part.

MANUFACTURING CONTROL llevise Scctions 8.1 and 8.2 to rend:

IMMERSTON CLEANINGlDEGREASING TYPE 1 EMULSION CLEANING it.

b.

c.

TYPE I1 AQUEOUS DECREASING

i I

lmmersc parts in the appropriatc solution, prepared, operated and maintained in accordancc with Scctionr 9.1 and 9.2, Unless ttic solution i s vigorously ngitatcd, parib' shall bo withdrawn and fc-immerscd at least 3 tinics to assuro complcte removal of oils and greascr.

Itinsc all piirts tlioroirghly i n uccordrnce with Section 8.3.

. . . * e .... $'?*? lr!F*! Proccssing of mixed mctnl alloy loids including elcctroplatcd deposits

with samc alloy subslratce in aqueous nlkalinc degrcasing solutions may rcsull in galviinic corrosion.

N 0 T 15: ( 1 ) If the interior surktccs of some parts are only piirlially accessible, nianu:tI nictbock such 8% flushing, wlplng. brushing, and shaking may be used to

supplcmeni immcrsion degrcasing.

N 0 '1' 13: ( 2 ) I h k or Position piirts lo prcvent diimiige, ensure good liquid circulation w w n d n l l part s t c h x s , and minimize part contact wilh LIic rack, and facilitate droinagc c i l solution from parts.

PROCESS SPEC TITLE P80 NUMBEn 6-14 PROCESS SPECIFICATION DMULSION CI.EANING

DEPARTURE (IMMEIWON AND SPRAY)

PnOCCSS OPEC NO,

BAC 5763

8.1.Y TYPE 11 AQUEOUS DEGKEASING (Continued) H. Imnictsc pirrts up IO IIIC lime nllowed in 19blc W in the apl)ropriatc solution (See Ihble X)

Ixcpnrcd, operated, and maintained in accordance with Scction 9.X and 9.Y. ’RI facilitate tile cumplclc removal of oils iind greases, parts mny be wilhdrawn and re-immerscd.

TAULE W MAXIMUM DEGREASINO ‘IIME, MINUTES

r SUBSTRATE

PROCESS SPEC TITLE

PROCESS SPECIFICATION EMUlSlON CLEANINO DEPARTURE (IMMERSION AND SPRAY)

I 2

Degnaser ' &? Solutions

Dmclenn 202 Yes

Bmlin 81SGD No

Biogeriic SE 373 Nu

niogcnic SE 371 No

A-2000 Yes'

PSD NUMBER PROW88 QPEC NO 6-14

ffi 5 OF 12

RAC 5763

CLASS 1 (Chemical Pmccssing Follows) 1 x x

x x

x x

x x

x x

x x x

x x x

1L

i_ m

"a:

W z

* I.0W PICESSYrcE ONLY

b. llcrnovc l h c paris from thc dcgrciiser solulion iitnk. Enirappcd tlegreaser solu(ion may bc rcmaved by tilling piirlslrack. Processing slmll be perlormcd so a s 10 minimize drying of soluiiori on tlic part surfiices.

Rinse 811 paris Iliorocifihly in accordance with Section 8.3,

Clicck the sudacc for soil rcmoviil i n accordance with Scction 11, and rccycle parts as ncccssary. Thc lutiil cumulalivc time rhc solution i s in contact with tlic part shall not cxcccd (Iic li111e ~ [ ~ c ~ j r r c d in 'Ihblc W. 130 no1 ;illoy pwls lo dry following Class 1 proccssinfi. bur conlinuc subscqucnt chwnicnl proccssing inimedialcly lollowifi); rinsing. !:or Clitss % processing, dry (air or dryer) tlic 6iirfwcs n k r rinsing: kccp sudnccz rrcc of i i l l coniainin;ition.

c . 11.

L'.

. . .

PROCOGG GPCC TITLC POD NUMDCn PROCESS SPECIFICATION !3MULSION CLl3ANINQ 6-14

DEPARTURE (IMMERSION AND SPKAY) PG 6 OF 12

PROCCOG SPEC NO.

BAC 5763

8.2

8.2.X

8.2.Y

SPRAY CLEANINGlnECiIII’ASINC

TYPE I CLEANING a.

11.

Spray parts in thc appropriate soltltion prepared, operated and maintained in accordance with Swlions 9.1 and 9.2. Parts sliall IJC rwckcd i n E U ~ I u manner thiit the impinging rprny or subsequent wush contacts all portions of thc parts. Rinse all parts thoroughly in rmrdancc with Section 8.3.

’

c.

TYPE I1 AQUEOUS DECREASING ......... $?.l! :r!?.? Processing of mixcd mcral alloy loads including electroplated deposits

with the same alloy substretc in aqucous alkallnc dCgrCaShI& solutions may rcsult in galvanic corrosion.

N 0 T P,: ( I ) If the interior sudaccs of somc parts arc only prirtially accessible, manual mcthods such as flushing, wiping, brushing and shaking may be used to

supplcmcnt spray dcgrcrsing.

ensurcs cood solution contact with all part surfaccs. Minimize n c k contact wllli IIIC parts.

N 0 T E: (2) Place parts in racks in a manncr which prevents parts damage and which

Spray parts lor no longer ttinn tlic time specified in lkble W in Ihc appropriate solution (See ’Ihble X) prcprrcd, opcrnted, and meintaincd in accordance with Section Y.X and Y.Y.

Entrapped dcgreiiser solution may bc removed hy tilting partdrack. t’roccssing shall be pcrlormed so as ti! in in imiw drying of dcgreascr solution on the pwt surfaces.

Rinse 811 parts thoroughly in accordancc with Section 8.3.

Chcck the surface tor soil removal in accordrncc with Section 11, and rccyclc parts as necessary. The total cumulative time the solution is in contact with the part shall not exceed the tlmc spccified in ‘1hl)le W.

Do not allow parts to dry (air or drycr) following Class 1 proccssing, but continue suliscqucnt chemical processing immediately lollowing rinsing. For Class 2, dry lhc surface.s aftcr rinsing. m d keep turkiccs free of all contamination.

. ' . . . . ..

PROCESS SPECIFICATION DEPARTURE

PROCESS SPEC TITLE P90 NUM~ER PROCESS GPCC NO. 6-14

BAC 5763 EMUISION CLEANING (IMMERSION AND SPRAY)

9

9.1.

9.2

Y.X

3.Y

MAINTENANCE CONTROL

Hcvisc Scctions 9.1 ;ind 9.2 titles to read as follows, and add tlic following ncw Scctions:

PREPARATION OF TYPE I BMULSJON CLEANER SOLUTlONS

OPERATION AND MAINTE.NANCI! OF TYPE I EMULSION CLEANER SOLU'JIONS - PREPARATION or TYPE II AQUEOUS DEGREASER SOLUTIONS - For each 100 gallons of final solution, mitkc the following ndditions: a.

Ir.

Add at Ica$I 112 of the nmount or water required, SCC Ttblc Y (100 gallons niinus the dcgrchscr solulion concentrate mnkcup quantity). Slowly add the amount of dcgrcascr solution concentrate required in WAC Y and mix thoroughly.

N 0 T F,: Add the undiluted clcnncr solution under the surface of ilic watcr to minimize solvent loss.

C. Add the rctnaining required amount of water. OPERATION AND MAINTENANCE OF TYPE I1 AQUEOUS DEGKEASER SOtUTl6NS a.

I ) .

c.

Anitlyze solutions &hcr makeup and as rcquircd io maint,ain correct dilutions throughout their lilc.

N 0 1 S: Some aqttcotts dcgreaser solutions scpafatc during solution operation, which may result in changcs in Critical material 1)alanccs within these formulations. For lliesc clcgrenser solutions, it is rccommended that the dcgrcaser solutions bc mrinttiined I)y solution drrwout and replaccmcnl with appropriate volumes of prcmixcd makeup solutions at the mnxiiiwm pcrmissiblc concenrratlons spccified in 'IBble Y.

Skim or filicr the solutions ns often as neccssnry to maintain clcrn solutions and parts. Operate and maintain thc ljpe I1 degrcaser SOlutions in accordance with Thbk Y.

I PROCESS SPEC TITLE I PM) NUMBER I PROCE88 BPEC NO.

I 6-’4 I BAC 5763 PROCESS SPECIFICATION EMUISION CLEANINO

DEPARTURE (IMMERSION AND SPRAY)

9.Y SOLWTYONS (Coiititiucd)

OPERATION AND MAINTENANCE OF TYPE I1 AQUEOUS DECREASER

TAlllB Y PREPARATION. OPEKATION AND MAINTBNANCE OF TYPE 11 DEGEASER SO1.UTIONS

9.2

- I / - 2/

- 3/

RINSE WATEII Simy o r imnicrsion rinsing may bc used. The first rinse shall bc dcdicaled to lhc dcgreasing proccss. Sullicicnt water shall be flowing into (hc rinse tanks 10 niaintiiin the conlamimints in the f inal (clcnn) i h c stnyc below the following: R.

For linritations on d e p u c r solutions by Class and Grade, Sec’ihblc W. l l s c only cnougli physical agitalion or p ~ i u p circula(iun to prevent the emulsion from scpwtling. Never USC nir iigitiitlon of any form of heavy agitrtion. ’l‘hc iise of physicrl itgitation or ptimp circolntioa i s rccommended. Air agilation can IIC used povidcd the degccascr SOIution doer not foilm excessively.

‘lblal solids (dissolvcd plus undissolved):

(1) Dcgrcasing print to cheni ic~l proccssing (CIiiss 1) - 750 ppm

(2) Dcgrcasing prior to 1ic:il trealmcnt, rnrming or additional machining operations - SO00

(3) Othcr degreasing - 350 ppii

For degreasinfi prior to hcal trciltnient of ali iminum alloys, sulfnr concentration shnll not exceed lOn pp~i i . This limit is ii portion of the total conlamination limit and not in addition to il.

I’Pm

b.

PROCESS SPECTITLE

PROCESS SPECIFICATION EMUISION CLEANING DEPARTURE (IMMERSION AND SI'KAY)

11

11.1.

11.2

12

12.1

12.2

P60 NUMBER rnoccss SPE~

BAC 57( 6-14

REQUIREMENTS Revise to read as follows:

TYPE I IIl3QUIREMENTS After proccssing, surfaces shall bc free from all greasc, grcasc-pencil marks and other organic contnniinntioii.. Parts not meeting tlicsc rcquiremcnts shall Irc rcptocessed in accordance with Scctioii 8. Part wrfitces nre not rcqiiircd to be wnter break-lrcc after emulsion clcaning.

TYPE Ir III;QUIREMENI*S - ..- When visually examined witbout mngnUication aftcr aqueous degreasing and rinsing, parts shall I Ircc of residue, pitting$ ctchinfl, smut nnd soil or other contaminants. A wafer break-frcc surfnc is not iequirod, Add tho following new Scction:

TEST METHODS Type I1 candidate degrcaser solutions slrall bc tested and meet tho requirements of this section prior to inclusion into this spccilicntion.

ETCHING a. --

Degreasing solutions approved for use shall not cause etching or corrosion of the metal. This rcquire~ne~it shall be verlfied by a 24 hour exposufc of 1 by 2 lry 0.050 inch metal Specinienr in the degreasing solution. TllC tcsting shall bc donC at maximum opcrating tcmycratute with concentrricd dogreaser solution and degrcascr solution diluted to the maximum operatirig cunccntratlon (uppcr control limit) listed in '1ht)le Y, The types of nictals cxlwscd and mnxlmtim nl1owal)lt: wcipht chnnges follow in Section 12.lb. The rcyirired spcclmcns nnd maximum allowable wcight changes arc AS lollows:

(1) Clad alumlnum (2024-T3)

(2) Magncsium (AZ31)

(3) Low 01l0y stccl, bare (AIS1 4130)

(4) Cadmium pldlcd steel (DAC 5804)

( 5 ) 'I'ititnium alloys (GA1-4V)

(6) Nickel-lrascd wlloys (INCO 625) and Iliph Nickcl contclrt Fcrrous Alloys (A28G)

(7) CRES (Stainless Steel) Alloys

b.

+ I - 10 mg

i I- 20 mg

+ I - 30 mg + /- 10 nig

+ /- J nig

+ I - 30 nig

+ / - 30 q SAN1)WICH CORROSION -. . -

12.2.'1 TEST SI'EC1MI;NS R. l'iwcl Sizc: b. I'ancl Material:

2 by 4 by 0.040 i o 0.OGO inclits

( I ) Clad 707S-T6 nlumiili im itlloy ill accordnncc will1 QQ-A-250/13 (Option~il: Clnd 2024-1'3 in accordance with UU-A-2S0/5)

(2) Rare 7075-'1'6 aluminum alloy i n accordmce with QQ-A-2W12) (Optional: Il:rr(s 2024-T3 i n ;iccordanw with QQ-A-25014) Anodize i n nucordancc with IIAC 5019. 5884 of h111.-A-5625.

-24026 VllG 1,OJ

PROCQSS SPEC TITLE

PROCESS SPECIFICATION EMUISION CLEANING DEPARTURE (IMMEIWON AND SPRAY)

12.2.2 1'13S'l* I'ROCEDURE

PSO NUMBER PROCESS Spec NO 6-14

BAC 5763

a. b.

C.

d.

e.

r.

6.

lkst panels required: Eit;ht of each panel material listed in Scction I2.2.lb. Prepare two sandwich test specimens with cach mrlcrial as follows:

( I ) Cut a filter paper (Wlialman No. S or cquivalcnt) to 1 by 3 inches and place in (he

(2) Saturate the filtcr paper with the solution to bc tcslcd. Avoid excessive solution. (3) Place a second pancl of the same inaterial ovcr thc srtanted filter paper, forming a

'I'hc tcsting shall I)c pcrrormcd with the debrcascr snlulion 1) undiluted and 2) dilutcd to tlic upper'colrccntraticin level for tlic dilution given in 'Ihble Y. As a control, prepare lwo sandwich test specimens for each material in accnrdancc wilh Scction 12.2.26, cxcept use distillcd or deionized water instead of lhc solution to he C V R I U ~ I C ~ , for both spccimcns.

ceiitcr ol one piincl.

sandwich. Hold the sandwich logcther with waterproof lap&

Expose the test panel in a controlled Iruniidity cabinet in accordancc with l h e schedule in Ikblc z. Aftcr (Iic 64 hour humidity cxposure, separatc thc sitndwich and wash llrc pancls with water and fl sort bristlc brush. Ulni dry. Tbst specimcn corrosion shall nol cxceed the following: (1) Class 1 and Class 2,

Grades lJ and C The undiluted dcgrcnsec shell producc no more corrosion nnd staining than does un undilutcd solution or Dltraclcan 282 (see Sectlon Sv.) when tested undcr the same conditions. The dilutcd dcgrcaser shall producc no more corrosion and staining than docs a 12 percent solution by volutnc of Darxlean 282 (SCC Scction Sv.) when lcstcd under the same conditions.

(3) Class 2 Grade A

'I'hc degreaser shall produce no corrnsion in excess of the control spccimen when testcd undiluted or dilutcd.

... . . I PROCESS SPEC TITLE I PSO NUMBER I PAOCEW SPCC NO I IJAC 5763 I EMULSION CLEANING I (IMM@RSlON AND SYRAY)

PROCESS SPECIFICATION DEPARTURE

12.2.2 TEST PROCEDUllR (Cotitinued)

TAnl,l? Z SANIIWICII CORROSION TEST SCIII?I)ULE

- I / %tal tcsting time i s 168 Iioun. INTERGRANULAR ATTACK Dogrcescr solutions approved for iiso sl~all no1 ~ ( L U S C inlergranular ailack in cxcess 01 0.0002 inch or cnd grain pilting in cxccss oTO.nOl inch when tenlcd in accordance with nSS 7213. See Section 12.1 tor lis1 uf materlals lo be lestcd, exccpl omit cadmium plalcd sleel (BAC $804) specimens.

-.. 12.3

CORROSION RESIS1’ANCD - 12.4

Dcgrcnscr solutions approved for use shall have I U S S C ~ l l ie corrosion rcsistance rcyclircments of 5AC Sf19,‘I)~ie I , Clash A using the pcoposcd Oegreaqer snlulions prior io alkaline cleaning.

PAOCKSS SPEC TITLE

PROCESS SPECIFICATION EMUISION CLEANING DEPARTURE (IMMERSION AND SPRAY)

12.5

12.6

12.7

12.8

12.9

PSD NUMOCR PROcEss SPEC NO.

6-14

PG 12 OF 12 BAC 5763

PAINT ADHESION a.

b.

Prepare six C1;iss C and three Class E test panels in accordance with 13MS 10-11. Perform dcgreasing prior to alkallnc clcrinlng using the prnpnscd dcgrcaser solution. Apply I3MS 10-11, "Qpc I prlnicr and RMS 10-1 1, 'Wpe I1 topcoat to six Class C panels in accordance wilh BMS 10-1 1. Apply DMS 10-11,5pe I primcr only tn tlircc Cluss I! lest pancls in accordance with IlMS 10-11. Test thrcc Class C pancls in accordancc with test procedures dcscribcd in BMS 10-1 1 Cor dry adhcrion. ' k s t thrcc Clnss C pancls in accordance with tcsL procedures dcscribcd in IlMS 10-11 for wct adhesion. Rst three Class E pancls in accordancc with test prncodures dcscribcd in BMS 10-1 1 for impact rcsiutance. No topcoat or primcr shall be rcmovcd by rl ie tapc, or on impact, from any of the pancls tested in accordancc with this scction.

c.

d.

e.

1.

SULFUR CONTENT Chemical bnalysis shiill be performed to dctcct any sulkir or sullur compounds in the dejycascr soliilion dilu(cd to tlic concentrations specificdin Tiblc Y . Dcgreaset solutions approved for usc shall contain no more than 1UU ppni sultur in any chcniical form,

14YI)ROGEN EMBRITTLEMENT Dcgrcasing solutions approved for use shall not rausc hydrogen cmbriltlemcnt dnmage to plaled or Ui~llliitcd steel parts. FWth electropliited and unplatcd AIS1 4340 notchcd round bar tensile spccinicns, v p c l a in itccordancc with ASTM I: 519, shirll be usctl to qualify the degrcasing solulion. 1)cgrensing solutions SIIRII IIC tcslc*d :it conccntrated (as-supplied) solution strcnglh and i it thc uppcr control limit concentration of 'Ihblc Y. a.

b.

Perform hydrogen embrittlemen! tcsling on iinplated notched tensilc b u s in accordancc with ASTM E' 519 to qualify degrcasing solutions for Class 1 and Class 2, Ccadcs A and 1%.

I'crlorin hydrogen enibriltlemcnt testing on cudniium plaled notched tensilc bars in accordance with ASTM F 519 to qciiilify dcgrciising sololions for Class 2, Gradc C processing.

STRESS CORROSION ('I'I'TANTWM ALLOYS O N 1 3 1ki;rciising solutions approved for use sliall not musc #tress corrusion cracking in titanitrm alloy ptirls, wlicn tested in accordance with ASTM 1' 945, Proccdurc A.

IIYDROGEN CON'I'ENT (TITANIUM AI,LOYS ONLY)

Degrcasing solutions approved for usc shall not increaec the hydrogcn contciit of titanium alloy parts to niorc than 20 ppm wlicn testcd in acc.ordancc with l l K 5753. Exposurc lime shall bc H minimum of 40 minulcs a t opcmting coiiditions of 'IRblc Y for (his test.