Baby Safety / Compounds / PCB-77 (3,3',4,4'-tetrachlorobiphenyl)

Is PCB-77 (3,3',4,4'-tetrachlorobiphenyl) safe for babies and kids?

Context-dependent for kids

Not medical or professional safety advice, and not a substitute for a qualified clinician — consult one. Full disclaimer →

Infants accumulate PCB-77 (3,3',4,4'-tetrachlorobiphenyl) through breast milk (bioconcentration), placental transfer, and dust ingestion. Persistent pollutants concentrate in fatty tissues with extended half-lives in developing organisms.

What is pcb-77 (3,3',4,4'-tetrachlorobiphenyl)?

Also known as: 3,3',4,4'-Tetrachlorobiphenyl, PCB 77, 3,4,3',4'-TETRACHLOROBIPHENYL, Biphenyl, 3,3',4,4'-tetrachloro-.

CAS number: 32598-13-3
Molecular formula: C12H6Cl4
Molecular weight: 292.0 g/mol
SMILES: C1=CC(=C(C=C1C2=CC(=C(C=C2)Cl)Cl)Cl)Cl
PubChem CID: 36187

Risk for babies

Context-dependent

Neonates and infants up to 12 months have incomplete blood-brain barrier development, immature Phase I/II metabolic enzymes (particularly CYP3A4, UGT1A1), and higher gastrointestinal permeability. Equivalent doses produce higher internal concentrations and longer residence times.

What to do: Minimize infant exposure through source control. For breastfeeding mothers: reduce maternal exposure. For formula-fed infants: use certified low-migration bottles and verified water sources. Consult pediatrician regarding any concerns.

Risk for pregnant and nursing people

Context-dependent

Regulatory consensus

2 regulatory and scientific bodies have classified PCB-77 (3,3',4,4'-tetrachlorobiphenyl). The classifications differ — that's the data.

Agency	Year	Classification	Notes
IARC	2016	Group 1	Group 1 via the IARC entity 'Polychlorinated biphenyls, dioxin-like, with a Toxicity Equivalency Factor (TEF) according to WHO (PCBs 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189)', which names PCB-77 among its twelve congeners (Vol 107, 2016); PCBs as a class are also Group 1 (Vols 18, Sup 7, 107).
EDC Assessment	—	Confirmed endocrine disruptor

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where kids encounter pcb-77 (3,3',4,4'-tetrachlorobiphenyl)

Food Chain — fish, dairy, meat (bioaccumulation)

Safer alternatives

Lower-risk approaches that achieve a similar outcome to PCB-77 (3,3',4,4'-tetrachlorobiphenyl):

Non-PCB dielectric fluids (natural ester, silicone)
Trade-offs: Natural esters: higher fire point but lower oxidation stability. Silicone: non-biodegradable.

Relative cost: 1.5-2× (silicone); 1.2× (natural ester)

Frequently asked questions

Is pcb-77 (3,3',4,4'-tetrachlorobiphenyl) safe for kids?

What products contain pcb-77 (3,3',4,4'-tetrachlorobiphenyl)?

PCB-77 (3,3',4,4'-tetrachlorobiphenyl) appears in: fish (Food chain); dairy (Food chain).

What should I do if my child is exposed to pcb-77 (3,3',4,4'-tetrachlorobiphenyl)?

Minimize infant exposure through source control. For breastfeeding mothers: reduce maternal exposure. For formula-fed infants: use certified low-migration bottles and verified water sources. Consult pediatrician regarding any concerns.

See PCB-77 (3,3',4,4'-tetrachlorobiphenyl) in the baby app

Look up products containing pcb-77 (3,3',4,4'-tetrachlorobiphenyl), compare to alternatives, and explore the full data record.

Open in baby View raw API data

Sources (2)

PubChem (2026) — database
IARC Monographs Vol 107: Polychlorinated Biphenyls and Polybrominated Biphenyls — PCBs Group 1 (carcinogenic to humans); sufficient evidence from occupational cohort studies; NHL, melanoma, liver cancer; AhR and non-AhR mechanisms; Aroclor mixtures and dioxin-like congeners evaluated (2016) (2016) — iarc_monograph

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for medical, pediatric, legal, or regulatory advice. Why we built ALETHEIA →