Charfi et al. 2026 — Packaging effects on heavy metals and phthalates in Spanish commercial olive oils
This study measured ten metals (Cu, Fe, Zn, Pb, Al, Cd, Cr, Sb, As, Ni) and phthalates (DEHP, DIBP, DiNP) in 18 commercial Spanish olive oil samples across four oil grades and six packaging types, collected across two harvest campaigns (2021/2022 and 2022/2023) by ICP-MS. Copper exceeded IOC/EU limits (0.1 mg Cu/kg oil) in several premium and pomace samples; Cd was not detected in any sample; As was absent across all samples; and Pb exceeded the 0.1 mg/kg regulatory limit in only one sample (EVOO in ceramic containers, 0.10 ± 0.03 mg/kg). Antimony was absent in all containers despite its use as catalyst in PET polymerization. Aluminium containers contributed elevated Al to the contained oil. Among phthalates, DEHP was detected in 6 of 18 samples, and DiNP exceeded the EU specific migration limit in one PET-packaged sample.
Key numbers
Heavy metals (Table 3, mg/kg oil, 2021/2022 campaign unless noted):
Pb:
- EVOO-P1 (glass): 0.01 ± 0.00
- EVOO-L1 (PET): 0.01 ± 0.00
- VOO1 (PET): 0.01 ± 0.00
- OO1 (PET): 0.02 ± 0.00
- OPO1 (pomace, Al/PE-LD): 0.02 ± 0.00
- EVPR1 (porcelain): 0.10 ± 0.03 [exceeds 0.1 mg/kg limit]
- EVTI1 (tin): 0.02 ± 0.01
- EVAL1 (aluminium): 0.03 ± 0.00
- EVCA1 (cardboard): 0.04 ± 0.02
- All 2022/2023 samples: 0.00 ± 0.00 (below detection)
Cd: not detected in any sample (0.00 ± 0.00 across all 17 samples)
As: not detected in any sample (0.00 ± 0.00 across all 17 samples)
Sb: not detected in any sample
Al (mg/kg oil):
- Most samples: 0.07–0.10
- EVAL1 (aluminium container): 0.67 ± 0.05 [notably elevated]
Ni (mg/kg oil):
- EVOO-P1: 0.20 ± 0.08 [highest]
- Most samples: 0.01–0.12
- EVAL1 (aluminium): 0.00 ± 0.00
Cr (mg/kg oil): 0.01–0.06 across all samples
Cu (mg/kg oil; IOC limit 0.1 mg/kg):
- Exceeded in: EVOO-P (0.11 ± 0.03), OPO (0.12 ± 0.01 to 0.18 ± 0.01), EVPR (0.18 ± 0.05), EVTI (tin, 0.12 ± 0.04), EVCA (cardboard, 0.12 ± 0.04)
- Below limit: EVOO-L, VOO, OO, EVAL (aluminium)
- Elevated Cu attributed to copper-based fungicide (copper oxychloride, hydroxide, sulfate) applied near harvest
Fe (mg/kg oil; IOC/EU limit 3.0 mg/kg): 0.09–0.30 (2021/2022) and 0.12–0.25 (2022/2023); all below limit
Zn (mg/kg oil; currently unregulated): 0.03–0.10 across both campaigns
Phthalates (Table 4, mg/kg oil; EU SML for DEHP = 0.6 mg/kg; SML sum for DEHP group = 0.6 mg/kg; SML for DiNP+DiDP = 1.8 mg/kg):
- DEHP detected in 6/18 samples: 0.1–0.23 mg/kg (all below individual 0.6 limit)
- DiNP detected in 2/18 samples: EVOO-L2 PET = 2.85 mg/kg [exceeds SML sum of 1.8 mg/kg]; EVOO-L2 glass = 1.15 mg/kg
- DIBP detected in 1 sample: EVOO-L2 PET = 0.51 mg/kg
- EVOO-L2 PET: DEHP group SML sum = 2.17 mg/kg [exceeds 0.6 mg/kg limit]
- Phthalates found in glass, porcelain, and cardboard containers as well as PET, suggesting production-process migration in addition to packaging migration
Methods
ICP-MS (Agilent 7900) with microwave digestion (ETHOS UP, 220 °C, 35 bar) of 0.80 g olive oil samples in HNO3/H2O2. Measured 32 elements: Be, B, Na, Mg, Al, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sb, Ba, Ti, Pb, U. Phthalates by GC-MS (Bruker Scion) in MRM mode. Each heavy metal determination conducted five times. Two harvest campaigns (2021/2022 and 2022/2023). Regulatory comparisons against IOC trade standard (COI/T.15/NC No 3/Rev. 19, November 2022) and EU regulations. Physicochemical characterization (acidity, peroxide value, UV parameters, pigments, oxidative stability) also performed; notable discrepancies found between commercial labelling and measured quality grade in several samples.
Implications
Certification: This paper establishes that Cd, As, and Sb are absent or undetectable in well-controlled Spanish commercial olive oil, while Cu exceedances arise from agricultural fungicide application timing (a production practice issue, not an intrinsic commodity risk). The finding that one porcelain-packaged EVOO sample marginally exceeded the Pb limit (0.10 ± 0.03 mg/kg vs limit 0.1 mg/kg) is an edge-case worth noting for packaging-material guidance. Al contamination from aluminium containers is a supply-chain lever.
Courses: The packaging-type breakdown provides a concrete module case study on how container choice interacts with heavy metal and phthalate migration, including the counterintuitive finding that glass and cardboard containers can also carry phthalate contamination via cap materials and production equipment.
App: For plain Spanish commercial olive oil, Cd and As can be treated as negligible; Pb and Cu are the primary regulated metals of concern, with Cu exceedances linked to agricultural practice rather than soil burden.