Mohammed et al. 2020 — Pb, Ni, Cr, Cd, Cu, and Mn in children’s toys and baby items by FAAS, with USEPA non-carcinogenic ingestion risk assessment (Trinidad and Tobago)

This peer-reviewed Journal of Environmental Chemistry and Ecotoxicology paper measures total Pb, Ni, Cr, Cd, Cu, and Mn in eighteen plastic children’s toys and baby items (eleven toys, seven baby items) sold in Trinidad and Tobago by Flame Atomic Absorption Spectrophotometry (FAAS) after 550–600 °C ashing and 70% HNO3 digestion. Pb, Ni, and Cr are detected in every sample; Cd, Cu, and Mn are detected in fewer than 40% of samples. Every Pb value in both the toys (2.5–34.5 mg/kg) and the baby items (2.1–14.7 mg/kg) exceeds the EN 71-3:2013 Category I total-content limit of 2 mg/kg; the purple jewellery (34.5 mg/kg Pb) and the rubber duck (4.1 mg/kg Cd) are reported as exceeding the EU regulatory ceilings cited by the authors. Despite these exceedances, the USEPA-style oral ingestion hazard quotients (Pb HQ 0.007–0.115; Ni HQ 0.0015–0.0113; Cr HQ 0.0036–0.0627) and the summed hazard indices (HI 0.0156–0.1447 across the eighteen items) remain below 1 under the authors’ default exposure model (15 kg body weight, 0.0002 kg/day intake, 5-year exposure duration), leading the authors to conclude that the items pose generally low ingestion risk to children. The paper also transcribes prior heavy-metals-in-toys ranges from Vietnam, Malaysia, India, Nigeria, China, and Palestine for context.

Key numbers

All concentrations are total elemental content (not migration) measured in triplicate by Flame Atomic Absorption Spectrophotometry (FAAS) following 550–600 °C dry ashing for 2 h and 130 °C nitric-acid (analar-grade 70%) digestion for 2 h, filtered through Whatman No. 541, made up to 50 mL with deionized water. Units: mg/kg of whole sample (samples were charred and ashed in entirety, not paint scraped). BDL = below detection limit.

Quality control (Results, p. 61)

• Spiked-sample percent recoveries: 102.9–114.4% across Pb, Cd, Cr, Ni, Cu, and Mn (spike concentration 1 mg/L applied to triplicate-prepared samples; method blank included).
• Calibration linearity (R²): 0.9944–0.9999.
• Replication: triplicate sample preparation with method blank and one spiked sample per analytical batch.
• Glassware preparation: Grade “A” volumetric glassware, washed and soaked overnight in 10% (v/v) HNO3, multi-rinse with deionized water, air-dried.

Per-sample concentrations — toys (Table 1, p. 62; mg/kg, mean ± SD where reported)

Per-sample concentrations — baby items (Table 1, p. 62; mg/kg, mean ± SD where reported)

Range summary across the eighteen-item sample (Results, p. 60–61)

Pb, Ni, and Cr were detected in all eighteen samples; Cd, Cu, and Mn were each detected in fewer than 40% of samples (Discussion, p. 61).

Regulatory-comparison statements made in the source

• Pb vs EN 71-3:2013 Category I (2 mg/kg total content; Discussion p. 61): all eighteen samples exceed this limit. The lowest Pb value reported (rattle 2.1 mg/kg) sits just above the limit; the highest (purple jewellery 34.5 mg/kg) is roughly 17× the limit.
• Pb vs EU regulatory limit (cited in abstract as the basis for exceedance counts): the abstract states “two samples exceed the regulatory limit for lead and one exceeded the regulatory limit for cadmium set by the EU.” The two Pb exceedances are not explicitly enumerated in the body but, by inspection of Table 1 relative to the EN 71-3 90 mg/kg migration limit referenced elsewhere, the abstract appears to reference the EN 71-3:2013 Category I 2 mg/kg total-content limit rather than the 90 mg/kg migration limit; on that basis the body’s “lead levels for both the toys and baby items were higher than the EN 71-3:2013 Category I limit of 2 mg/kg” statement reconciles the abstract’s “two samples” count against the same reference only if “two samples” refers to the two values explicitly called out in the body (purple jewellery 34.5 mg/kg and teething ring 14.7 mg/kg). The body’s claim that all values exceed the 2 mg/kg limit is the operative quantitative reading.
• Cd vs EU regulatory limit: the rubber duck (4.1 mg/kg Cd) is the one Cd exceedance noted in the abstract. The body does not specify whether the reference value is the EN 71-3 Category I total-content limit for Cd (1.9 mg/kg) or the EN 71-3 Category III migration limit (17 mg/kg); the rubber duck value exceeds the former but not the latter.
• Cr (III) and Ni vs “recommended limits” of 37.5 and 75 mg/kg respectively (Discussion p. 61): all eighteen samples comply with both. The source does not name the underlying standard explicitly in the body but the values match EN 71-3:2013 Category I total-content limits for chromium(III) (37.5 mg/kg) and nickel (75 mg/kg).
• Cd, Cu, and Mn vs EN 71-3:2013 Category I (Discussion p. 61): all detected values are below the cited Category I limits for these metals.

USEPA-style non-carcinogenic ingestion risk assessment (Table 3, p. 63)

Exposure model parameters (Methods, p. 60–61):

Reference doses (RfD, mg/kg/day; Methods p. 61, citing Ismail et al. 2017 and Patrick-Iwuanyanwu & Udowelle 2017):

Hazard-quotient ranges across the eighteen samples (Table 3 + Results p. 62–63):

Average Daily Dose of ingestion (ADD, mg/kg/day) ranges per the abstract: Pb 3 × 10⁻⁵ – 1.0 × 10⁻⁴; Ni 3.1 × 10⁻⁵ – 2.3 × 10⁻⁴; Cr 1.0 × 10⁻⁵ – 2.0 × 10⁻⁴.

Hazard-index (HI = ΣHQ) range across the eighteen items: 0.0156 (Pacifier silicone) – 0.1447 (Rubber duck) (Table 3). The authors’ framing: HQ < 1 indicates no expected non-carcinogenic adverse effect; HI < 1 indicates no expected adverse effect from cumulative exposure across the six metals.

Comparison-with-other-countries summary (Table 2, p. 62)

Reported by the authors as a literature-comparison table (mg/kg total-content ranges for plastic toys):

These are external-study transcriptions for context, not measurements made in the present paper.

Methods (brief)

• Sample collection: 18 plastic children’s toys and baby items intended for children under 5 years of age, obtained from the Trinidad and Tobago Bureau of Standards. Eleven toys and seven baby items (enumerated in sample_population).
• Sample preparation: soft plastic samples cut into approximately 0.5 cm pieces; brittle samples crushed to powder. Approximately 0.5–3 g of sample weighed into porcelain crucibles, charred on a hot plate until fuming ceased, then ashed in a furnace at 550–600 °C for 2 h. Crucibles cooled; 10 mL of analar-grade 70% nitric acid added and left to pre-digest 24 h at room temperature; samples digested at 130 °C for 2 h; cooled; filtered through Whatman No. 541; made up to 50 mL with deionized water.
• Analytical method: Flame Atomic Absorption Spectrophotometry (FAAS) for Pb, Ni, Cr, Cd, Cu, and Mn. The Methods section reads “samples were then analysed for Pb, Ni, Mg, Cd, Cr, and Cu by Flame Atomic Absorption Spectrophotometry (FAAS)”; the abstract, Table 1, and Table 3 consistently report Pb, Ni, Cr, Cd, Cu, and Mn (manganese, not magnesium), so the Methods text contains a “Mg” typo for Mn that the rest of the paper corrects. The actual analytes are Pb, Ni, Cr, Cd, Cu, Mn.
• Matrix: total elemental content of whole-toy/whole-baby-item material (charred-and-ashed bulk), not migration extract and not paint coating in isolation. This contrasts with EN 71-3 standard migration testing, which extracts soluble elements from sample surfaces under HCl conditions simulating gastric extraction.
• QC: triplicate samples, method blank, spiked sample (1 mg/L of Cd, Cr, Ni, Pb, Cu, and Mn); spike percent recovery 102.9–114.4%; calibration R² 0.9944–0.9999.
• Speciation: none reported. Cr is total Cr, not Cr-VI vs Cr(III) speciated. Pb is total Pb. As (arsenic), Hg (mercury), Sn (tin), and Sb (antimony) are not part of the analyte panel — outside the analyte scope of this paper.
• Risk assessment: USEPA-style ADD/HQ/HI per Ismail et al. (2017), with RfDs from Ismail et al. (2017) and Patrick-Iwuanyanwu & Udowelle (2017). Body weight 15 kg, intake rate 0.0002 kg/day, exposure duration 5 years.
• No migration testing performed. The authors note that EN 71-3:2019, ASTM F963-17, and ISO 8124-3:2020 are the standard methods for migration assessment and acknowledge that the present total-content data are not directly comparable to the migration limits set by those standards. The body explicitly states that 8 mg/day estimated per-child intake of toy components is the basis of the EN 71-3 migration limit calibration (citing Kumar and Pastore 2007).

Implications

• HMTc audit implications. For HMTc work on Pacifiers and sucking/teething aids, Children’s jewelry, Infant bottle nipples, Sippy cups and toddler drinkware, and the various toy product rows, this source contributes per-sample total-content occurrence data for Pb, Ni, Cr, Cd, Cu, and Mn across eighteen retail-purchased Trinidad and Tobago samples. The Pb data are the most actionable for HMTc threshold work: every sample exceeded the EN 71-3:2013 Category I 2 mg/kg total-content limit, and the purple jewellery (34.5 mg/kg) and teething ring (14.7 mg/kg) are the upper-tail observations. The Cd data identify the rubber duck (4.1 mg/kg) as a Category I exceedance per the EN 71-3 reference. The total-content basis here is not directly comparable to migration-based EN 71-3 enforcement but is the operative basis when the HMTc standard is set on bulk-substrate composition rather than on simulated saliva extract. The Mn HQ value for the rubber duck (0.901, near 1) is the single largest non-Pb hazard-quotient value in the dataset and merits attention in any HMTc rubber-duck or squeeze-toy threshold work.
• Occurrence data contribution. Direct evidence for: children’s jewelry (4 samples), pacifiers and sucking/teething aids (3 pacifiers + 1 teething ring = 4 samples), infant bottle nipples (1 sample), sippy cups and toddler drinkware (1 sample), squeeze toys (1 rubber duck), rattles (1 sample), stuffed/plush toys (1 pink bear), and substrate materials of generic plastic toys (4 samples: 2 building blocks, doctor set, car, princess doll). The single-sample-per-form structure for several baby-item categories is a meaningful limitation noted in the verification notes.
• Regulatory landscape. The paper anchors against EN 71-3:2013 Category I total-content limits and the EN 71-3 migration-limit framework, with the authors flagging that Trinidad and Tobago and the wider Caribbean have no local regulations on heavy metals in toys and baby items. The cited “recommended limits” of 37.5 mg/kg (Cr-III) and 75 mg/kg (Ni) appear consistent with EN 71-3:2013 Category I values for these metals though the source does not name the standard explicitly.
• App. The per-sample data are relevant to a future infant-contact-product screening surface for non-food exposure pathways. The high-Pb purple-jewellery and teething-ring observations are useful upper-tail anchors when the app reasons about hand-to-mouth and chewed-product exposure scenarios for the under-5 age group.
• Courses. A useful worked example of total-content FAAS analysis (not migration) of consumer toys with a transparent USEPA-style HQ/HI calculation. Pedagogically suitable for illustrating the distinction between total elemental content and migrated (bioaccessible) content, and the limitations of total-content-based risk assessment for infant-contact products under chewing/sucking behaviour.
• Microbiome. Not directly applicable.

Wiki pages this source may touch

• lead
• cadmium
• chromium
• nickel
• copper
• manganese
• childrens-jewelry
• pacifiers-and-sucking-teething-aids
• infant-bottle-nipples
• sippy-cups-toddler-drinkware
• toys-squeeze
• toys-rattles
• toys-stuffed-bean-bag
• toys-substrate-materials

Verification notes

• Source identification. Mohammed T, Dial D, Maharaj D, Smith C, Persad N, Mohammed S, Mohammed A. 2020. Heavy metals in children’s toys and baby items commonly sold in Trinidad and Tobago. Journal of Environmental Chemistry and Ecotoxicology 12(1):59–64. DOI 10.5897/JECE2020.0465. Article number FD8075463937. Received 5 May 2020; Accepted 4 June 2020. Author affiliations: Department of Chemistry, Department of Life Sciences (University of the West Indies, St. Augustine, Trinidad and Tobago), and the Trinidad and Tobago Bureau of Standards.
• License. CC BY 4.0 (stated in the article footer: “Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License”). The article footer also notes “Author(s) retain the copyright of this article.”
• Access URL. The article is published by Academic Journals at academicjournals.org/JECE; the canonical landing page is constructed from the article number. Marked as the academicjournals.org abstract URL pending verification of the exact link form.
• Author count. Seven authors total: Mohammed T (corresponding), Dial D, Maharaj D, Smith C, Persad N, Mohammed S, Mohammed A. Two of the authors share the surname Mohammed (Terry Mohammed and Sasha Mohammed and Azad Mohammed are three separate authors with the same surname); preserved in authors: as separate entries.
• Tier rationale. A-tier: peer-reviewed primary research with documented methods (FAAS, ashing + HNO3 digestion), explicit QC (spike recovery, calibration linearity, triplicate samples, blank), transparent risk-assessment parameter list, and per-sample data table. The Methods section contains a “Mg” typo for Mn — this is a clerical error in the Methods prose only; Table 1, Table 3, and the abstract all consistently report Mn (manganese) and not Mg (magnesium). The typo does not affect tier assignment.
• Methods-section Mg vs Mn typo. The Methods sentence “Samples were then analysed for Pb, Ni, Mg, Cd, Cr, and Cu by Flame Atomic Absorption Spectrophotometry (FAAS)” prints “Mg” where the rest of the paper (abstract, Table 1, Table 3, Discussion, Conclusion) reads “Mn”. The analyte panel is six metals — Pb, Ni, Cr, Cd, Cu, Mn — and the abstract’s concentration ranges (Mn 0.03–4.22 mg/kg, Cu 0.03–2.15 mg/kg) are internally consistent with the Mn-not-Mg reading. The source page reports the analytes as Pb, Ni, Cr, Cd, Cu, Mn and flags the typo here in the verification notes rather than propagating it into the page body.
• Brand-firewall (Part 12). The source identifies samples by color and product type only (“Jewellery (Yellow)”, “Building Blocks (Pink)”, “Pacifier (brown)”, “Pacifier (bright star)”, “Pacifier (silicone)”, “Rubber duck”, “Teething ring”, etc.). No brand names, manufacturer names, or distributor names appear in the published Table 1 or Table 3. The page therefore contains no brand attribution and no brand-firewall concern arises. The product-form descriptors used in the source (silicone vs orthodontic, soft plastic vs brittle, color labels) are preserved as the source uses them.
• Scientific-method vendor names (Part 12 Exception 2). The paper does not name the FAAS instrument vendor or model. The reagent named is “analar-grade nitric acid (70%)”; the filtration paper is “Whatman No. 541 Hardened Ashless”; these are preserved as scientific-method identifications. No further vendor-specific equipment is identified in the Methods.
• Wiki/HMTc firewall (Part 2). The page reports the source’s own findings, regulatory comparisons, and risk-assessment outputs as the source states them. It does not propose HMTc thresholds, does not compare these values to other corpus papers in a synthesis sense, and does not soften or strengthen the source’s exceedance language. The Implications section identifies what the source contributes to HMTc threshold work for the relevant rows without proposing a threshold value.
• Speciation flag. Cr is reported as total Cr (Cr); the paper does not speciate Cr-VI vs Cr-III despite the Discussion referring to “Chromium (III) and nickel levels were below the recommended limit of 37.5 and 75 mg/kg” — the 37.5 mg/kg value matches the EN 71-3:2013 Category I limit for Cr-III, but the analytical method (FAAS following total dry-ashing acid digestion) measures total Cr, not Cr-III specifically. The frontmatter declares Cr (total). No iAs, MeHg, or Cr-VI claims are made. Pb is total Pb (the paper does not distinguish organolead).
• Matrix and basis. Total elemental content of charred-and-ashed bulk sample, in mg/kg of dry-weight whole-toy or whole-baby-item material. Not migration data and not paint-scrape-only data; the entire sample piece (whether soft-plastic-cut or brittle-crushed) is ashed and digested. This is materially different from EN 71-3 migration testing and from paint-scrape-only measurements such as Igweze et al. 2020 (Nigeria toys; igweze2020-china-toys-nigeria-pb-cd-as.md). Per-sample HQ/HI is computed against the 0.0002 kg/day intake rate which Grẑetic and Ghariani (2008) propose as an order-of-magnitude small-component-ingestion estimate; the EN 71-3 calibration uses 8 mg/day (Kumar and Pastore 2007). The source cites both reference values but uses the 0.0002 kg/day (200 mg/day) figure in its own HQ/HI calculation, which is roughly 25× higher than the EN 71-3 reference 8 mg/day; this conservatism direction is acknowledged in the source but the implications for cross-paper comparability are not discussed.
• Frontmatter metals: [Pb, Cd, Cr, Ni, Cu, Mn]. These are the six measured analytes. Listed in the corpus’ standard abbreviation order (Pb, Cd, Cr, Ni, Cu, Mn). Cr is total Cr (the page slug chromium covers total Cr).
• Frontmatter ingredients: [] is correct — no food matrices involved. Toys and infant-contact items are hard-goods consumer products, not food ingredients.
• Frontmatter matrices: [] is correct — toys and infant-contact items are hard-goods consumer-product matrices, not food/biomonitoring controlled-vocabulary matrices for routing purposes. Matches the precedent set by Masu 2016 (Malaysia pacifiers/sippy cups) and Igweze 2020 (Nigeria toys).
• Frontmatter products routing. Eight product-page targets declared. The eighteen samples decompose as follows: four children’s jewellery items → childrens-jewelry; three pacifiers + one teething ring → pacifiers-and-sucking-teething-aids (the umbrella scaffold; the source does not separately enumerate teething aids vs pacifier sub-forms); one bottle nipple → infant-bottle-nipples; one sippy cup → sippy-cups-toddler-drinkware; one rubber duck → toys-squeeze (rubber-duck-style squeeze toy); one rattle → toys-rattles; one pink bear → toys-stuffed-bean-bag (plush stuffed toy); four generic plastic toys (two building-block sets, doctor set, yellow car, princess doll) → toys-substrate-materials (the bulk-substrate-of-plastic-toys product page). The Trinidad and Tobago samples are total-content (ashed + HNO3-digested whole-sample), so the substrate-material slug is the closer fit than toys-painted (which is the paint-scrape-only slug used by Igweze 2020). Princess doll is routed to substrate-materials rather than to a separate doll slug because the taxonomy snapshot does not contain a doll-specific scaffold and the analytical basis is bulk substrate. Per Part 5b, the routing layer is the canonical assignment of route_kind per (source, target-page) pair; the declarations here are the routing-fanout inputs, not the route-kind assignments.
• Frontmatter jurisdictions: [TT, EU]. Trinidad and Tobago is the primary jurisdiction (samples drawn from Trinidad and Tobago retail via the TT Bureau of Standards). EU is included because the paper anchors its regulatory comparison against EN 71-3:2013 Category I limits (EU normalised standard) and against the EU regulatory limit for Pb and Cd in toys; the EU jurisdiction declaration captures the regulatory-context dimension rather than the sampling-location dimension.
• Sample-size structure. N = 18 retail items (11 toys + 7 baby items). Triplicate analytical replication per sample (where indicated by ± SD in Table 1) but single-sample-per-form for most baby-item categories. The single-sample-per-form structure (e.g., one teething ring, one rubber duck, one bottle nipple, one sippy cup, one rattle) is a meaningful limitation for treating these values as distributional anchors; the per-sample HQ/HI values are the operative outputs and are reported per-item.
• Regulation references in body. EN 71-3:2013 (Category I total-content limit for Pb at 2 mg/kg; Category I cited for Cd, Cu, Mn without explicit values); EN 71-3:2019 (Safety of toys — Migration of certain elements; cited as the current migration standard); ASTM F963-17 (Standard Consumer Safety Specification for Toy Safety); ISO 8124-3:2020 (Safety of toys — Part 3: Migration of certain elements). USEPA RfDs cited (Pb 0.0004, Ni 0.02, Cr 0.003, Cd 0.001, Cu 0.04, Mn 0.014 mg/kg/day) via Ismail et al. (2017) and Patrick-Iwuanyanwu & Udowelle (2017). None of these standards currently has a dedicated wiki/regulations/ page in the corpus, so the body references them by name and reference rather than wikilinking to non-existent regulation slugs. New regulation pages are not created speculatively from this single source.
• Abstract vs body Pb-exceedance count discrepancy. The abstract states “two samples exceed the regulatory limit for lead” but the Discussion (p. 61) states all samples exceed the EN 71-3:2013 Category I 2 mg/kg limit. The internal reconciliation reading: the abstract’s “two samples” likely refers to two samples whose Pb values are roughly an order of magnitude over the limit (purple jewellery 34.5 mg/kg and teething ring 14.7 mg/kg, both called out elsewhere) while the Discussion correctly characterises every value as above the 2 mg/kg limit. The source page reports both characterisations as the source states them and does not silently resolve the discrepancy; readers should treat the Discussion statement (universal exceedance of the 2 mg/kg limit) as the quantitatively operative reading.
• Audit subagent (2026-06-01) flagged Building Blocks (Pink) HI internal contradiction; verified against source — Table 3 (p. 63) prints HI = 0.179 for Building Blocks (Pink), which exceeds the Abstract’s stated HI range of 0.0156–0.1447. The arithmetic sum of the row’s printed HQ values (Pb 0.113 + Ni 0.002 + Cr 0.004 + Cd 0 + Cu 0.0001 + Mn 0 = ~0.119) does not match the printed HI 0.179 either. This is a source-internal inconsistency in Table 3 that the source does not reconcile. The Range Summary on this page transcribes the Abstract’s HI range as the source states it; the Building Blocks (Pink) Table 3 value is preserved verbatim in the per-sample table. No correction applied to the page; the discrepancy is the source’s, not the wiki page’s.
• Audit subagent (2026-06-01) flagged products/childrens-jewelry as missing from docs/gpt-collaboration/taxonomy-snapshot.md; verified against live wiki — finding was a false positive because wiki/products/childrens-jewelry.md exists in the live wiki as a provisional scaffold (frontmatter: hmtc_category: pending_taxonomy_review). The taxonomy snapshot at docs/gpt-collaboration/taxonomy-snapshot.md is dated 2026-05-18 (per its generated: field) and predates this page’s creation, so the audit subagent saw a stale snapshot. The slug is correct; no correction applied.
• Near-duplicates. None identified in the corpus at this writing. The closest precedents are Igweze et al. 2020 (Nigeria Chinese-import toys, FAAS, paint scrapes only, Pb/Cd/As panel; igweze2020-china-toys-nigeria-pb-cd-as.md) and Masu 2016 (Malaysia pacifiers/sippy cups, NGO comparative testing for BPA/phthalates/nitrosamines with no metals measurements; masu2016-pacifiers-sippy-cups-my.md). Neither overlaps in sample identity or in analyte panel with the present Trinidad and Tobago paper.
• Raw integrity. raw_sha256 = 0a0b5d1790e3b78d6560f5a6efeab22866700cd9db59870b6d12d4392a34be04 verified by shasum -a 256 against the file at raw_path.
• Folder context. PDF lives in raw/Manual Fetch Kimi /May 21 Kimi_Agent_Download Corruption Issue/_extracted_infantcontact_02_Teethers_Pacifiers/02_Teethers_Pacifiers/ — the Kimi download-corruption-issue folder for the infant-contact pacifiers/teethers subtree. The filename 14_2020_fd8075463937.pdf encodes (sequence 14, publication year 2020, Academic Journals article number fd8075463937).

Page history

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