Baby Safety / Compounds / Paclobutrazol

Is Paclobutrazol safe for babies and kids?

Elevated risk for kids

Infants are more vulnerable to Paclobutrazol than children or adults due to immature hepatic/renal clearance, higher intake-to-body-weight ratio, rapid organ development, and increased gastrointestinal absorption.

What is paclobutrazol?

The IUPAC name is (2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)pentan-3-ol.

Also known as: PBZ, Bonzi, Trimmit, Cultar.

IUPAC name
(2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)pentan-3-ol
CAS number
76738-62-0
Molecular formula
C15H20ClN3O
Molecular weight
293.79 g/mol
SMILES
CC(C)(C)C(O)C(CC1=CC=C(Cl)C=C1)N1C=NC=N1
PubChem CID
40326

Risk for babies

Elevated risk

Infants are more vulnerable to Paclobutrazol than children or adults due to immature hepatic/renal clearance, higher intake-to-body-weight ratio, rapid organ development, and increased gastrointestinal absorption.

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

High risk

Pregnancy alters the metabolism and distribution of Paclobutrazol, potentially increasing fetal exposure. The developing embryo/fetus is vulnerable during organogenesis (weeks 3-8) and neurological development. Placental transfer should be assumed.

Known reproductive toxicant (GHS H360) or confirmed endocrine disruptor. Placental transfer is presumed. Fetal exposure during critical developmental windows may cause structural malformations, growth restriction, or functional deficits.

What to do: Minimize exposure during pregnancy and lactation. Consult healthcare provider regarding specific risks. Consider alternative products with lower hazard profiles.

Regulatory consensus

3 regulatory and scientific bodies have classified Paclobutrazol. The classifications differ — that's the data.

AgencyYearClassificationNotes
EPA—Registered pesticide (plant growth regulator/fungicide). Food tolerances for mangoes, apples, cherries, and other tree fruits.
EU—Not approved as plant protection product in EU (Reg. EC 1107/2009). MRL set at default 0.01 mg/kg for most commodities.
WHO/JMPR—ADI 0-0.02 mg/kg bw/day

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 paclobutrazol

  • Agriculture — mango orchards (flowering induction), apple/cherry trees (growth control), ornamental plants (height control in nurseries)
  • Turf Management — golf courses, roadside turf, athletic fields
  • Arboriculture — utility line tree management (trunk injection), urban tree growth control
  • Illicit Agriculture — cannabis cultivation (compact plant growth) — NOT registered for this use; residues transfer to consumer products

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Paclobutrazol:

  • Prohexadione-calcium (Apogee/Regalis)
    Trade-offs: Non-persistent (rapidly degraded). Lower hepatotoxicity concern. Less effective on tropical fruits.
  • Uniconazole
    Trade-offs: Same triazole class but more potent (lower use rates). Similar toxicological profile.

Frequently asked questions

Is paclobutrazol safe for kids?

Infants are more vulnerable to Paclobutrazol than children or adults due to immature hepatic/renal clearance, higher intake-to-body-weight ratio, rapid organ development, and increased gastrointestinal absorption.

What products contain paclobutrazol?

Paclobutrazol appears in: mango orchards (flowering induction) (agriculture); apple/cherry trees (growth control) (agriculture); golf courses (turf management); roadside turf (turf management); utility line tree management (trunk injection) (arboriculture).

What should I do if my child is exposed to paclobutrazol?

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.

Why do regulators disagree about paclobutrazol?

Paclobutrazol has been classified by 3 agencies including EPA, EU, WHO/JMPR, 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 Paclobutrazol in the baby app

Look up products containing paclobutrazol, compare to alternatives, and explore the full data record.

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Sources (1)
  1. — expert_curation

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 →