Download Safety evaluation strategy of non

Safety evaluation strategy of
non-intentionally added substances
(NIAS)
Sander Koster
Sander Koster
Safety evaluation of FCM
Outline
• Safety evaluation of FCM
• Definition of non-intentionally added substances (NIAS)
• NIAS safety evaluation strategies
• Novel safety strategy applied to UNKNOWN substances;
an example on a paper FCM
• Challenges for applying TTC to unknowns
• Outlook
Sander Koster
Safety evaluation of FCM
Safety evaluation of FCM: intentionally added
substances (IAS)
Traditionally, check composition starting materials FCM (IAS) +
compliance specific migration limit (SML) substances.
Examples of IAS;
IAS
Monomers
Pre-polymers
Unknowns?
Base materials
Antioxidants
Polymer production aids
Catalysts
…
No full safety evaluation!
Sander Koster
Safety evaluation of FCM
Safety evaluation of FCM; IAS + NIAS
Plastics legislation requires IAS and NIAS (non-intentionally added
substances) to be assessed.
article 3 of the Plastic Regulation (EU) No 10/2011 ‘nonintentionally added substance (NIAS)’; an impurity in the
substances used or a reaction intermediate formed during the
production process or a decomposition or reaction product.
Sander Koster
Safety evaluation of FCM
Definition NIAS; recitals Plastic Regulation (EU)
No 10/2011
(18) Substances used in the manufacture of plastic materials or articles may contain
impurities originating from their manufacturing or
extraction process. These impurities are non-intentionally added together
with the substance in the manufacture of the plastic material (non-intentionally
added substance – NIAS). As far as they are relevant for the risk assessment the
main impurities of a substance should be considered and if
necessary be included in the specifications of a substance. However it is not
possible to list and consider all impurities in the authorisation. Therefore
they
may be present in the material or article but not included in the
Union list.
Sander Koster
Safety evaluation of FCM
Definition NIAS; recitals Plastic Regulation (EU)
No 10/2011
(20) During
the manufacture and use of plastic materials and articles reaction
and degradation products can be formed. These reaction and degradation
products are non-intentionally present in the plastic material (NIAS). As far as they are
relevant for the risk assessment the main reaction and degradation products of the intended
application of a substance should be considered and included in the restrictions of the
substance. However it is not possible to list and consider all reaction and degradation
products in the authorisation. Therefore they should not be listed as single entries in the
Union list. Any potential health
risk in the final material or article arising
from reaction and degradation products should be assessed by the
manufacturer in accordance with internationally recognised scientific
principles on risk assessment.
Sander Koster
Safety evaluation of FCM
Examples NIAS
Example of NIAS;
Oxidation product e.g. oxidized irgafos 168
Oligomers?
Impurities
Contaminants of processing/transportation
Starting substances to make e.g. bisphenol-A (acetone, phenol)
…
Does it matter that definition of NIAS can be interpreted differently?
No
Final article should not endanger human health
Yes
- If detected peak is NIAS it may be present in article
- If detected peak is IAS it should be petitioned.
 task ILSI working group on NIAS
Sander Koster
Safety evaluation of FCM
How to do your safety evaluation for NIAS?
Applying traditional approach requires that EVERYTHING that
migrates is identified and risk assessed (full composition, IAS+NIAS).
Obtain information on NIAS throughout the value chain?
Feasible?
What to do if full identification is not possible…?
Sander Koster
Safety evaluation of FCM
Innovation concept for safety evaluation of NIAS
response
Introduction
Current
approach
Innovation
Exposure threshold
Most relevant data to start with:
10 ppb
Identity (purity, size, shape, surface area, etc…)
Physico-chemical properties
(chemical reactivity, (photo-) catalyticrt
rt
surface charge, etc…)Focus on toxicological relevance
Focus onreactivity,
full identification
• Identify & quantify
all in
components
• Threshold
for identification
uprated
Changes
either identity and/or
physico-chemical
properties
may from
• Hazard & risk assessment for each
10 ppb to 90 µg exposure per day
introduce specific hazards
individual component
• Hazard & risk assessment only
• Low detection levels required
for substances above exposure threshold
• CRM substances < 10 ppb not covered • High risk compounds covered by
targeted analyses
Sander Koster
Safety evaluation of FCM
Innovation concept for safety evaluation of FCM
Generic health limit based on the TTC decision tree
(Kroes et al 2004)
Basic principle in toxicology:
" Everything is poison and there is poison
in everything. It is the dose that makes a
thing a poison."
Paracelcus father of the toxicology
Risk = Exposure x Hazard
Sander Koster
Safety evaluation of FCM
Response
STEP 1
Translate response into intake and identify peaks
corresponding with intakes of more than 90 µg/p/d
Rennen et al.
2011
Exposure threshold1
Intake
rt
1
STEP 2, exclude:
STEP 3, exclude:
STEP 4
proteins (or assess safety)
non-essential/heavy metals
metal containing compounds
dioxin-like chemicals
high potent genotoxic compounds
organophosphates
(structural alerts for) genotoxicity
Identify and assess
compounds with
intakes >90 µg/p/d
and non-excluded
compounds
based on Cramer class III
STEP 5, assess allergenicity
Sander Koster
Safety evaluation of FCM
Step 1: Screening techniques
Combination of techniques covering broad spectrum of
substances
• Headspace/SPME GC-MS
Volatile substances
• GC-FID/MS
Semi-volatile subst.
Medium polar/apolar subst.
• Derivatisation* GC-FID/MS
Non/semi-volatile subst.
Small polar/medium polar
subst.
• LC-UV/light scattering/MS
Non volatile subst.
Polar – apolar subst.
*silylation makes non-volatile substances more volatile
Sander Koster
Safety evaluation of FCM
Step 1: Example NIAS; semi volatiles (GC-MS)
Tenax
10 days 60 °C
GC-MS,
AT-5 column
A bundance
T IC : p p n d _ 0 2 3 .D \ d a ta .m s
550000
500000
90 µg daily intake
(line to guide the eye)
Note;
check compliance IAS+ use
chemical information to predict NIAS
450000
400000
IS
350000
300000
250000
200000
10 ppb
(line to guide the eye)
150000
100000
50000
1 0 .0 0
T im e -->
1 5 .0 0
2 0 .0 0
2 5 .0 0
3 0 .0 0
3 5 .0 0
4 0 .0 0
4 5 .0 0
Sander Koster
Safety evaluation of FCM
Step 1: Example NIAS; non-volatiles (LC-ELSD/UV)
-14.00
IS
-14.20
-14.40
90 µg daily intake
-14.60
-14.80
-15.00
-15.20
Tenax
10 days 60 °C
H2O  ACN,
RP column
mV
-15.40
-15.60
-15.80
-16.00
-16.20
-16.40
-16.60
-16.80
-17.00
-17.20
-17.40
5.00
10.00
15.00
20.00
25.00
30.00
Minutes
35.00
40.00
45.00
50.00
55.00
Sander Koster
Safety evaluation of FCM
Step 2: exclude known high toxic compounds and
other TTC excluded classes
Not all classes relevant for FCM. Exclusion based on available
information; expert judgment and/or targeted analysis
• Aflatoxins (relevant for material of biological origin)
ok
• Azoxy substances (not likely in FCM)
ok
• N-nitroso compounds (in rubber materials)
ok
• Steroids (negligible in FCM)
ok
• Dioxins (biological origin + chlorine containing FCM)
To do
• High MW substances e.g. polymers (in general not of tox relevance) ok
• Non-essential metals (targeted analysis: ICP MS)
ok
• Proteins (screen for allergenicity, see step 5)
ok
• Organophosphates (targeted analysis;TTC of 18 µg/p/d) ok
Excluded by analysis - ok
Excluded by expert judgment - ok
Sander Koster
Safety evaluation of FCM
Step 2: Example NIAS; organophosphates (GC-NPD)
18 µg daily intake
blank
blank
NB
-pesticides excluded with targeted LC-MS
-LC-MS accurate mass to exclude P
Sander Koster
Safety evaluation of FCM
Step 3: Exclude (structural alerts for) genotoxicity
Chemical analysis
Excluding genotoxicity by chemical analysis very difficult (21 structural
alerts).
Bioassays
Conventional assays
AMES, MLA, CA
not developed for complex matrices
(higher concentration sensitivity required)
New developments; e.g. Bluescreen
• Luminescent assay (sensitive)
• Human cell line covering endpoints of Ames, micronucleus and
mouse lymphoma assay and cytotoxicity
• GADD45a gene
• Assay validated for pharmaceutical formulations
• High throughput! (96 well-format)
• Test protocol developed for complex matrices
Sander Koster
Safety evaluation of FCM
Step 4:
Evaluation of compounds above
90 µg daily exposure
• Identification and quantification of substances > 90µg daily exposure
• Determine substance specific threshold
• Refinement Cramer classification using:
 Cramer (1978)
 open source applications such as Toxtree
• Substance specific toxicity data
 retrieved from public literature
 toxicity data from structural related substances (readacross).
Risk assessment; from ~60 substances (FOP) to ~10 substances (TTC)
Sander Koster
Safety evaluation of FCM
Step 5: Assess allergenicity
• Proteins might give allergic responses in sensitive people and
should therefore be evaluated
• FCMs with ingredients of biological origin might contain proteins
• If considered relevant screening for known allergens and specific
risk assessment
• Here assumed that allergens are not part of the FCM under
investigation
Sander Koster
Safety evaluation of FCM
Challenges for applying TTC approach to unknowns?
Combination toxicity – dose/concentration addition
Current analytical approaches do not take this into account.
However, at low exposure …
• Synergistic effects only when 2 or more compounds are above
effect level (not likely at low TTC exposure)
• Cumulative effects is depending on potency, limited effect to be
expected at low (90 µg/p/d) exposure. Eg.:
• 21 or 26 organophosphates all at 90 µg/p/d => 360 or 250 µg/p/d
when potency corrected for acute or chronic effects, respectively
• 7 or 11 triazoles all at 90 µg/p/d => 240 or 300 µg/p/d when
potency corrected for acute or chronic effects, respectively
Leeman et al. in preparation
Sander Koster
Safety evaluation of FCM
Challenges for applying TTC approach to unknowns?
Bio-accumulating substances
Log Po/w as ‘marker’ for accumulation
Three studies where no relation was found between log Po/w and
NOAEL:
• Ravenzwaay (2011): 111 NOAELs from developmental rat studies
(Log Po/w: -4.3 to 15; median 2.12)
• Ravenzwaay (2012): 104 NOAELs from developmental rabbit
studies (Log Po/w: -13 to 15)
• Kalkhof (2012): 824 NOAELs from (28/90 day) repeated dose
studies (Log Po/w: -2.76 to 7.1 [5th/95th Percentile]; median 2.36)
• Relevance of accumulation at low exposure???
(polyhalogenated and metals already excluded)
Sander Koster
Safety evaluation of FCM
Challenges for applying TTC approach to unknowns?
Universal response detectors used?
-GC-FID/MS proven to give ‘uniform’ response for different
analytes (factor ~6)
-Light scattering detectors (e.g. ELSD) for LC have fair
uniformity (factor ~6) when operated with post-column addition
of reverse gradient
Do you detect all substance in extracts?
No technique exists that can do so, however state-of-the-art
used here.
Sander Koster
Safety evaluation of FCM
Challenges for applying TTC approach to unknowns?
TTC should not be used for mixtures containing unknown chemical
structures?
Combination toxicity effects marginal?
Analytical screening as good as other approaches?
What more arguments needed?
Sander Koster
Safety evaluation of FCM
Outlook
• Efficient evaluation of NIAS requires novel approaches.
• Innovation concept for safety evaluation is pragmatic and feasible.
• Increase analytical screening from 10 ppb to 90 µg daily exposure
• Challenges
• Information transfer through value chain
• Analysis
• Relevant exposure data (FACET?)
• Bioaccumulation, combination toxicity
• Applying to mixtures of unknown chemical structures
• Sensitivity genotoxicity assays
• EFSA
• More demonstrators needed!
• ILSI guidance on NIAS in preparation.
Sander Koster
Safety evaluation of FCM
Thank you for your attention!
Acknowledgements
Lisette Krul
Winfried Leeman
Monique Rennen
Geert Houben
ILSI and members of ILSI WG on NIAS
See you in autumn 2013 (?) at ILSI!
For more information: [email protected]
TNO, The Netherlands: www.tno.nl/foodsafety
Sander Koster
Safety evaluation of FCM
TTC decision tree; what’s in it?
Exclude:
high potent genotoxic compounds
-aflatoxin-like chemicals
-azoxy compounds
-N-nitroso compounds
present
Substance specific risk assessment/
Legal limits
excluded
Exclude:
-proteins
-non-essential/heavy metals
-steroids
-metal containing compounds
-dioxin-like chemicals
-high molecular weight substances
excluded
present
Substance specific risk assessment/
Legal limits
present
Exclude:
Structural alerts for genotoxicity
TTC: 0.15 microgram/p/d
excluded
present
Exclude:
Organophosphates
TTC: 18 microgram/p/d
excluded
TTC: 90 microgram/p/d
Sander Koster
Safety evaluation of FCM
LC-ELSD
-10.00
-12.00
-4.00
-6.00
-8.00
Bisphenol-A - 26.486
Tebufenozid - 32.561
0.00
-2.00
17-OH Progesteron - 29.160
Quinine - 15.707
2.00
Sulphamethazon - 17.599
4.00
Reversed
gradient
- 3.004 - 2.742
Methionine-1Sorbitol
-8.00
6.00
Methionine-2 - 3.988
-6.00
8.00
Methionine-2 - 3.991
Bisphenol-A - 26.493
-4.00
- 2.737
Sorbitol
- 3.006
Methionine-1
-10.00
-12.00
-14.00
16.044
mV
-2.00
10.00
mV
0.00
17-OH Progesteron - 29.160
2.00
Quinine - 15.720
4.00
Normal
gradient
Sulphamethazon - 17.605
6.00
Tebufenozid - 32.556
12.00
8.00
-14.00
-16.00
-16.00
-18.00
-18.00
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
20.00
22.00
24.00
26.00
Minutes
28.00
30.00
32.00
34.00
36.00
38.00
40.00
42.00
44.00
46.00
48.00
50.00
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
20.00
22.00
24.00
26.00
Minutes
28.00
30.00
32.00
34.00
36.00
38.00
40.00
42.00
44.00
46.00
48.00
50.00