Pet Safety / Compounds / PCBs (Polychlorinated Biphenyls)

Is PCBs (Polychlorinated Biphenyls) safe for dogs and cats?

Elevated risk for pets

Dietary exposure via fish-based food; thyroid effects documented in companion animal sentinels.

What is pcbs (polychlorinated biphenyls)?

Also known as: Polychlorinated biphenyls, POLYCHLORINATED BIPHENYL 99.

CAS number
1336-36-3
Molecular formula
C12H5Cl5
Molecular weight
326.4 g/mol
SMILES
[*]C1=C([*])C([*])=C(C([*])=C1[*])C1=C([*])C([*])=C([*])C([*])=C1[*] |$_R1;;;_R1;;_R1;;;_R1;;_R1;;;_R1;;_R1;;_R1;;_R1;;_R1$,c:1,5,8,12,20,t:16,RG:_R1={Cl* |$;_AP1$,lp:0:3|},LOG={_R1:;H;>0}|
PubChem CID
40470

Risk for dogs

Elevated risk

Dietary exposure via fish-based food; thyroid effects documented in companion animal sentinels.

Regulatory consensus

6 regulatory and scientific bodies have classified PCBs (Polychlorinated Biphenyls). The classifications differ — that's the data.

AgencyYearClassificationNotes
IARC2013Group 1 (carcinogenic to humans)Non-dioxin-like PCBs: malignant melanoma, NHL; dioxin-like PCBs Group 2A; Monograph 107
US EPA1996Likely to be carcinogenic to humansLiver tumors; banned 1979 but persistent globally
EPA CTX / IRIS—B2 (Probable human carcinogen - based on sufficient evidence of carcinogenicity in animals)
EPA CTX / NTP RoC—Reasonably Anticipated to be a Human Carcinogen
EPA CTX / IARC—Group 1 - Carcinogenic to humans
EPA CTX / EPA OPP—Group B2 Probable Human Carcinogen

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 pets encounter pcbs (polychlorinated biphenyls)

  • Food — Fatty fish (salmon, trout, mackerel), Dairy products and animal fats, Shellfish from contaminated waters
    Bioaccumulation in aquatic food chains; fatty tissues concentrate PCBs; primary exposure route for general population
  • Environmental — Sediment in rivers and harbors, Soil near former manufacturing or disposal sites, Marine and freshwater ecosystems
    Persistent organic pollutant; resistance to degradation; widespread distribution despite 1979 ban
  • Occupational Settings — Electrical equipment maintenance (transformers, capacitors), Hazardous waste handling facilities, Decommissioning of older industrial equipment
    Workers may contact PCB-containing oils and equipment; exposure during remediation activities
  • Indoor Environments — Dust from deteriorating old electrical equipment, Air from buildings with older fluorescent lighting ballasts, Caulk and sealants in older buildings
    Legacy exposure from products manufactured before 1979 ban; degradation of aging materials releases PCBs

Safer alternatives

Lower-risk approaches that achieve a similar outcome to PCBs (Polychlorinated Biphenyls):

  • Inherently flame-resistant materials (wool, modacrylic, Nomex)
    Trade-offs: Higher material cost. Limited color/texture options.
    Relative cost: 2-4×
  • Barrier fabric technology
    Trade-offs: Adds manufacturing step and cost
    Relative cost: 1.2-2×

Frequently asked questions

Is pcbs (polychlorinated biphenyls) safe for pets?

Dietary exposure via fish-based food; thyroid effects documented in companion animal sentinels.

What products contain pcbs (polychlorinated biphenyls)?

PCBs (Polychlorinated Biphenyls) appears in: Fatty fish (salmon, trout, mackerel) (Food); Dairy products and animal fats (Food); Sediment in rivers and harbors (Environmental); Soil near former manufacturing or disposal sites (Environmental); Electrical equipment maintenance (transformers, capacitors) (Occupational settings).

Why do regulators disagree about pcbs (polychlorinated biphenyls)?

PCBs (Polychlorinated Biphenyls) has been classified by 6 agencies including IARC, US EPA, EPA CTX / IRIS, EPA CTX / NTP RoC, EPA CTX / IARC, with differing conclusions. 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. See the regulatory consensus table on this page for the full picture.

See PCBs (Polychlorinated Biphenyls) in the pets app

Look up products containing pcbs (polychlorinated biphenyls), compare to alternatives, and explore the full data record.

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Sources (2)
  1. IARC Monographs Volume 107: Polychlorinated Biphenyls and Polybrominated Biphenyls (2013) — regulatory
  2. US EPA: Polychlorinated Biphenyls (PCBs) — IRIS Assessment (1996) — regulatory

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