CSTEE 2003 - organotin exposure from consumer products and food-contact materials

The European Commission’s Scientific Committee on Toxicity, Ecotoxicity and the Environment reviewed non-food consumer and environmental exposures to organostannic compounds, while explicitly noting that foods and food-contact materials contribute to total exposure. This is an A-tier regulatory opinion and exposure-context source, not a primary occurrence survey. The opinion keeps organotin species such as MBT, DBT, TBT, MOT, DOT, and TPT distinct from total elemental tin.

Key numbers

• Document identity: CSTEE opinion adopted at the 38th plenary meeting on 12 June 2003; the reviewed report version was Final Report 19 July 2002; extracted PDF has 14 pages.
• Species groups reviewed in the report: monomethyltins (MMT), dimethyltins (DMT), monobutyltins (MBT), dibutyltins (DBT), tributyltins (TBT), monooctyltins (MOT), and dioctyltins (DOT). The CSTEE flagged triphenyltins (TPT) and other alkyltins as important omissions.
• Environmental exposure context: site-specific local predicted environmental concentrations for production were 0.2 - 0.4 µg/L for MBTC, DBTC, MOTC, and DOTC, and up to 0.015 for TBTC.
• PVC-processing context: applying the selected low-volatility emission factors predicted local environmental concentrations up to 3 µg/L for mono- and dialkyl compounds; wood treatment gave TBTC values of about 0.16 µg/L.
• Measured-water comparators cited by CSTEE: older regional data indicated up to 2 and 16 µg/L of MBT and DBT in fresh water; a more recent investigation found 0.076, 0.81, and 3.6 µg/L of MBT, DBT, and TBT, respectively.
• TBT ecotoxicity context: the reviewed report used a chronic NOEC of 60 ng Sn/litre for Daphnia magna. CSTEE noted imposex observations at lower concentrations, including 1 ng TBT /litre in dog-whelk and a 0.1 ng TBT-Sn/litre threshold in Ocinebrina aciculata. It also cited flounder effects after exposure to 0.1 mg TBTO/kg diet.
• Food-contact context: the opinion states that food wrapped in organotin-stabilised PVC may add to total exposure and that butyltins from cookies prepared using silicone-coated baking paper may be problematic.
• Baking-paper risk statement: CSTEE cites the Scientific Committee on Food conclusion that the estimated migration level exceeded the specific migration limit for dioctyltin compounds by a factor of 10, while the SCF judged occasional consumption unlikely to pose a risk in the phase-out context.
• Child-cookie correction: CSTEE says the highest cookie value of 15.9 µg/kg bw/day was a miscalculation and should be 2 µg/kg bw/day, from 50 g x 318 µg Sn/kg = 15.9 µg Sn for an 8 kg child.
• Cycling-shorts correction: CSTEE recalculated TBT in the exposed area as 0.1 m2 x 1.2 kg/m2 x 45 mg Sn/kg = 5.4 mg Sn, with uptake estimated at 0.09 µg/kg bw/day.
• Paddling-pool scenario: daily exposure over the 20 days of use was 0.21 µg/kg bw for an 8 kg child, calculated from 5.1 µg Sn/L x 0.33 L / 8 kg bw.
• PVC-toy oral-exposure proxy: using a doll DINP oral intake of about 20 µg/kg bw/day, the opinion estimated DBT oral intake at about 0.2 µg/kg bw/day if DBT concentration was 1 % of DINP and the same release factor applied.

Dust organotin concentrations

The opinion cites a study of parliament-building dust samples:

Toxicological reference and indoor-air scenario values

• TBT reference value used in the reviewed report: 0.27 µg/kg per day TBT as chloride, based on WHO 1999.
• U.S. EPA benchmark cited by CSTEE: benchmark dose 0.68 ppm, corresponding to 0.03 mg/kg BW/day.
• CSTEE proposed adopting the low TDI value of TBT for DBT, DOT, and TPT for shared immunotoxicity, and treating effects as additive in the absence of contradictory data.

Annex 1 estimates DBT indoor-air exposure under four scenarios:

Methods (brief)

CSTEE reviewed a July 2002 risk-assessment report on non-biocidal organostannic uses, including polymer stabilisers, catalysts, wood preservatives, and selected consumer products. The opinion evaluates the report’s scenario assumptions, emission factors, environmental predicted concentrations, consumer-exposure calculations, toxicological reference values, and data gaps. It is not a laboratory study; the numbers are regulatory-review calculations, cited measurements, and CSTEE corrections to the reviewed report.

Implications

Certification (HMTc): This source is regulatory exposure context for organotin tin species in food-contact and consumer-product materials. It should not be pooled as a product occurrence distribution, and the organotin values should not be collapsed into total tin or inorganic tin.

Courses: The opinion is useful for teaching why organotin exposure cannot be treated as a single-source problem and why food-contact, toys, indoor air, dust, and environmental pathways can interact.

App: If organotin context is surfaced for food-contact packaging or children’s PVC materials, this source supports a qualitative distinction between organotin species and total elemental tin, and flags baking-paper/PVC-wrap and PVC-toy pathways as regulatory-review concerns.

Wiki pages this source may touch

• food-packaging-flexible-pouches-films
• bakeware
• toys-substrate-materials
• tin
• organotins

Verification notes

• PDF text was extracted with pdftotext -layout to /tmp/ingest.txt; the title pages, question list, environmental-exposure section, human-exposure section, answers to questions, references, and Annex 1 were checked against this page.
• Identity checks before creation: exact title phrase, raw SHA-256 88be80d9bbcb86798d187d983dc54109443244a614ff33d8624c0989fd491117, raw handle MFK_eu-risk-assessment-studies-on-targeted-consumer, and cite key cstee2003-organotin-consumer-exposure were searched in wiki/sources/ and evidence files; only intake/tracker CSV rows were found.
• DOI status: no DOI is printed in the PDF metadata or extracted text. The page uses doi: null and no_doi_assigned: true.
• Speciation: all tin-related values are organotin species or organotin-tin equivalents, not total tin or inorganic tin. Frontmatter uses Sn for element-level routing following existing organotin-source convention and links [[metals/organotins]] in the wiki-page list.
• Units and bases are preserved exactly as printed, including µg/L, ng Sn/litre, ng TBT /litre, mg TBTO/kg diet, µg/kg bw/day, µg/kg, mg/kg, µg/day, and µg/m3.
• The source’s toxicological reference values and migration-limit discussion are reported as CSTEE/SCF regulatory-review statements, not as HMTc thresholds.
• Closed-vocabulary check: product slugs use broad existing food-contact packaging, bakeware, and toy substrate rows. No exact baking-paper, PVC-flooring, wallpaper, indoor-dust, or paddling-pool product slug was invented; those contexts remain in prose.

Page history

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