NICKEL RELEASE REGULATIONS, EN 1811:2011 WHAT S NEW?

Transcription

1 NICKEL RELEASE REGULATIONS, EN 1811:2011 WHAT S NEW? BACKGROUND: EN 1811 is the intenationally ecognised test method which was devised almost 12 yeas ago to detemine the ate of nickel elease fom jewelley, spectacle fames and othe items. The test was devised to assess whethe aticles comply with the equiements of the EU Nickel Diective which esticts the elease ate of nickel fom aticles intended to come into diect and polonged contact with the skin and with post assemblies intended to be inseted into piecings in the body. Sensitisation to nickel can esult in sevee allegic eactions. The objective of the Nickel Diective is to educe the incidence of nickel dematitis by peventing non-compliant items fom eaching the maketplace. The EU Nickel Diective was oiginally intoduced in 1994, became enfoceable in 2000 and was amended and updated in The 2005 equiements wee subsequently amalgamated into the REACH egulation [Ref: REGULATION (EC) No 1907/2006, Enty 27 of Annexe 17 (REACH)]. REACH is a Euopean Union egulation concening the Registation, Evaluation, Authoisation and estiction of Chemicals. It came into foce on 1st June 2007 and eplaced a numbe of Euopean Diectives and Regulations with a single system. The Annex XVII of REGULATION (EC) No 1907/2006, came into foce fom 1 June 2009) Unde the legislation any manufactue, impote, wholesale o etaile in the supply chain will commit an offence if: They sell a post assembly intended to be inseted into a pieced pat of the human body unless the ate of nickel elease fom the post assembly is less than 0.2 μg/cm2/week; They sell jewelley items, including cetain metal clothing fastenes, if the ate of nickel elease fom those pats of the poduct which come into diect and polonged contact with the skin is geate than 0.5 μg/cm2/week.

2 They sell any jewelley items, including cetain metal clothing fastenes, whee these have a non-nickel coating unless the coating is sufficient to ensue that the ate of nickel elease fom those pats of the poduct which come into diect and polonged contact with the skin does not exceed 0.5 μg/cm2/week fo a peiod of at least two yeas nomal use of the poduct. CHANGES TO EN 1811:1998 Thee ae many factos which can affect the level and ate of nickel elease fom a nickel alloy. Apat fom the actual nickel content and composition of the alloy these include suface finish, non-homogeneity, and plating among othes. As a consequence, esults fom testing accoding to the EN 1811: A1:2008 standad test method have sometimes been shown to be subject to vaiability and uncetainty. This is acknowledged by the fact that the EN 1811:1998 method equies that the test esult be multiplied by a coection facto of 0.1 in ode to compensate fo these vaiables and ty to obtain a moe consistent and compaable nickel elease figue. Effectively this means that an aticle ecoding an actual elease ate of as much as 5.0µg/cm²/week o 2.0µg/cm²/week, depending upon type of aticle, when tested by EN 1811:1998 would still be deemed to be compliant to the Diective once the coection facto of 0.1 had been applied In 2010, the EU ganted a mandate to CEN TC 347 TG 1 (the Euopean Committee tasked with evision of the intenational standad) to examine the EN 1811:1998 test pocedue and the elated uncetainties. In ode to potect the health of the consume it wanted to develop and intoduce a moe eliable / obust pocedue, emove o educe the adjustment facto of 0.1 and delive a test method which was moe accuate and epoducible. Following the wok undetaken by the CEN Committee the 1998 standad has now been supeseded and eplaced with EN 1811:2011. SUMMARY OF DIFFERENCES BETWEEN THE 1998 AND THE 2011 STANDARD: The main diffeence between the 1998 and the 2011 standad is that the existing coection facto of 0.1 has been eplaced by an uncetainty of measuement (ut, = 46 %, ut, is elated to the elative epoducibility). This has the effect of effectively loweing the compliance limit fo nickel elease, so poducts which wee cuently compliant with the egulations may cease to be when tested to the evised standad. The new standad also featues a no decision categoy of esult due to the move away fom the use of a coection facto and adoption of an uncetainty of measuement appoach to assessing test esults. No decision captues the ange of esults whee, afte testing to the evised standad, no clea decision is possible, due to intepetation of the measuement of uncetainty of esults. A No decision vedict does not mean that the aticle is not compliant; but it means the supplie cannot claim that it is compliant. Unde such cicumstances the manufactue and/o impote shall be made awae by the laboatoy caying out the test that the mateial composition of the tested aticle may be unsuitable and consideation should be given to the use of altenative mateials.

3 Othe significant changes: The scope was expanded to include all post assemblies which ae inseted into pieced pats of the human body. The pepaation of the test solution has changed; ammonium hydoxide is no longe used and it has been eplaced by sodium hydoxide. The eason fo this is that ammonium hydoxide is unstable and can change concentation with time in stoage and also by evapoation, even duing the test pocedue and, theefoe, contibutes uncetainty to the activity of the test solution. Sodium hydoxide is a moe elatively stable alkali and unlike ammonium hydoxide, it does not fom complexes with nickel and the esulting test solution will be less active and, theefoe, less nickel will be eleased using the evised 2011 pocedue. The pocedue fo measuing the suface aea has now been defined in geate detail to educe vaiability, especially fo complex aticles. The standad also details that the 18 caat white gold nickel alloy quality contol sample (peviously efeed to as the efeence disc ) should only be tested once. The pevious pactice was to abade the suface to emove the nickel depleted laye and e-use; this pactice contibuted to vaiability as it was vey difficult to detemine how much to emove and, theefoe, the nickel depleted laye may not always have been entiely emoved. This new pactice should impove the epoducibility of quality contol sample test esults. The pocedue fo immesion of the test aticle in the synthetic sweat solution is defined in moe detail with the objective of educing vaiability. The method of calculating the nickel elease (that is the calculation fomula) is unchanged but NO adjustment facto (peviously x0.1) is applied in the fomula used in the 2011 standad. Revised citeia: The changes ae based on the esults of ound obin testing by a numbe of laboatoies. If a laboatoy can show that the measue of uncetainty of its own esults ae diffeent fom those obtained by the ound obin tial (46%) then it can set its own values fo noncompliance, 'compliance and values whee no decision is possible. Fo moe infomation with egad to this calculation please see end of document. In ode to detemine whethe a tested aticle is compliant /non-compliant o falls into the no decision categoy, specific values, calculated using a 46% measuement of uncetainty have been povided in the 2011 standad. As can be seen fom the compaison table below, this means that esults fom some aticles which wee peviously deemed to be compliant afte the coection facto had been applied will now be no decision o non compliant.

4 COMPARISON OF ACTUAL RELEASE VALUES En VS 2011 Fo aticles that shall show compliance with the migation limit of 0.5 μg/cm²/week an aticle (assuming a measuement of uncetainty of 46%) will be deemed to be 1998 Standad befoe coection facto of 0.1 Standad 2011 Noncompliant when nickel elease, µg/cm²/week is > Compliant when nickel elease, µg/cm²/week is No decision when nickel elease, µg/cm²/week is Not applicable >0.28 o <0.88 Fo aticles that shall show compliance with the migation limit of 0.2 μg/cm²/week an aticle (assuming a measuement of uncetainty of 46%) will be deemed to be Standad befoe coection facto of 0.1 Standad 2011 Noncompliant when nickel elease, µg/cm²/week is > Compliant when nickel elease, µg/cm²/week is No decision when nickel elease, µg/cm²/week is Not Applicable >0.11 o <0.35 UK Implementation of the 2011 standad: BSI ecognise that the supply chain will need some time to ensue goods comply with the new standad. They have theefoe elected to delay the withdawal of the Bitish standad BS EN 1811:1998 until Mach 2013, o wheneve the new standad, BS EN 1811:2011 becomes mandatoy by its inclusion in the REACH Diective, whicheve happens ealie. Howeve, othe EU membe states may choose to withdaw BS EN 1811:1998 and intoduce the evised standad immediately. This could cause confusion fo those tading in seveal EU counties. Fo these companies and all those with aveage stock tun, complying with the evised 2011 standad is the safest option. Spectacle Fames and Sunglasses: Spectacle fames and sunglasses which wee ealie included in the scope of EN 1811: A1:2008 standad ae now excluded fom the 2011 standad. The exemption was equested by the spectacle fame industy on the gounds that spectacle fames ae medical devices that have complex shapes, diffeent mateials and coatings, all of which contibute to the uncetainty of measuement. Additionally, because coated aticles have to be subjected to EN (coosion and wea teatment phase) befoe the EN 1811 test, this ceates futhe uncetainty. The spectacle fame industy has applied fo a mandate to develop a moe appopiate nickel elease test fo complex, coated spectacle fames and sunglasses. Until a moe appopiate nickel elease test fo

5 such complex, coated spectacle fames and sunglasses is developed, EN 1811: A1:2008 has been epublished unchanged as EN 16128:2011. MORE INFORMATION FOR THOSE WHO ARE INTERESTED IN THE CALCULATION: How the values detailed in the 2011 standad have been calculated: The esults of an inte-laboatoy compaison wee undetaken accoding to ISO 5725 which gave as an estimate fo the combined measuement uncetainty a value of ut, = 46 %. The pefomance chaacteistic ut, is elated to the elative epoducibility s of the 2 suface aea detemination s R, ( aea) and the analytical detemination of the nickel 2 elease s R, ( Ni) by the following equation: ut, sr, ( aea) sr, ( Ni) In ode to detemine whethe a tested aticle is non-compliant with its espective limit [i.e. 0.2 µg/cm 2 /week limit o 0.5 µg/cm 2 /week limit, espectively] a statistical test is applied. This test decides whethe a detemined nickel elease value significantly exceeds its limit, it is one-sided and detemines whethe the lowe bounday of the confidence inteval at a significance level of 0.05, also known as guad band ( See Note*), is equal to, o lage than the limit. The following equations demonstate how to calculate the values given in the evised standad meas lim 1 k( ) u ) ( t, lim meas ( 1 ( k( ) u t, )) Whee k(α) is the expansion facto fo the chosen significance level/guad band (i.e See Note*) )and the one sided t-test which gives a coesponding value of 1.65 fo such significance level. [Note: What significance level of 0.05 means*:- In statistical tem it means that ate of false non compliant esults is 5 % i.e. the pobability of a false ejection is 5 %. Please note statistically a value of 1.65 x measuement uncetainty (ut, = 46 %) will give a pobability of 5% false ejection (and a value of 2.33 x measuement uncetainty implies a pobability of 1%). lim coespond to the 0.2 µg/cm 2 /week limit (0.5 µg/cm 2 /week limit, espectively) meas is the mean of the eplicates of the nickel elease deteminations ut, = 46 %. The above equation shows the elationship between the measued value, the expanded measuement uncetainty and the limit values. Example 1: when nickel elease value is 0.2 µg/cm²/week o 0.2 µg/cm²/week (when coection facto of x0.1 is applied in the fomula), then coesponding compliant / noncompliant value based on 46% uncetainty at significance level of 0.05 but in absence of coection facto of x0.1 is

6 lim 0.2 / ( *46/100) i.e. lim 0.11 µg/cm²/week lim 0.2*( *46/100) i.e. lim 0.35 µg/cm²/week The above example shows that when uncetainty of 46% is taken into account then fo aticles that shall show compliance with the migation limit of 0.2 µg/cm 2 /week an aticle will be deemed to be compliant when the nickel elease value is less than o equal to 0.11 µg/cm 2 /week. Fo nickel elease values that ae geate than 0.11 µg/cm 2 /week but less than 0.35 µg/cm 2 /week no clea decision is possible fo compliance of this test aticle. The aticle will be teated non-compliant if nickel elease values that ae geate than o equal to 0.35 µg/cm 2 /week Example 2: when nickel elease value is 0.5 µg/cm²/week o 0.5 µg/cm²/week (when coection facto of x0.1 is applied in the fomula), then coesponding compliant / noncompliant value based on 46% uncetainty at significance level of 0.05 but in absence of coection facto of x0.1 is lim 0.5/( *46/100) i.e. lim 0.28 µg/cm²/week lim 0.5*( *46/100) i.e. lim 0.88 µg/cm²/week