Provisional Peer-Reviewed Toxicity Values (PPRTVs)

Tributyl Phosphate

CASRN 126-73-8

PPRTV Toxicity Values Summary Table

Noncancer Assessment

Estimate of Chronic Reference Dose for Oral Exposure (RfD)Last Updated: 11/08/2010
System RfD (mg/kg-day) Basis PoD UF Confidence
Other 1 x 10-2 Occasional salivation LOAEL : 32.5 mg/kg-day 3000 Medium
Species Studied: Rat
Duration: 7 day/wk, 13 weeks
Principal Study: Healy et al. 1995 (Bio-Research Laboratories 1991)
Note: The subchronic LOAEL is used as the POD for calculation because it is lower than other potential PODs.



Estimate of Subchronic Reference Dose for Oral Exposure (RfD)Last Updated: 11/08/2010
System RfD (mg/kg-day) Basis PoD UF Confidence
Other 3 x 10-2 Occasional salivation LOAEL : 32.5 mg/kg-day 1000 Medium/High
Species Studied: Rat
Duration: 7 day/wk, 13 weeks
Principal Study: Healy et al. 1995 (Bio-Research Laboratories 1991)
Note: Lethality from aspiration of saliva is an early cholinergic sign of organophosphate toxicity



Estimate of Chronic Reference Concentration for Inhalation Exposure (RfC)Last Updated: 11/08/2010
Data are inadequate to derive a chronic RfC.


Estimate of Subchronic Reference Concentration for Inhalation Exposure (RfC)Last Updated: 11/08/2010
Data are inadequate to derive a subchronic RfC.


Cancer Assessment

Weight of Evidence for CancerLast Updated: 11/08/2010
LI - Likely to be carcinogenic to humans


Estimate of Carcinogenic Risk from Oral ExposureLast Updated: 11/08/2010
Oral Slope Factor: 9 x 10-3 per mg/kg-day
Tumor site(s):
Cancer: Transitional cell and squamous cell carcinomas and papillomas
Species Studied: Rat
Duration: 2 years
Principal Study: Auletta et al. 1998a
Note: Linear low-dose extrapolation was conducted.


Estimate of Carcinogenic Risk from Inhalation ExposureLast Updated: 11/08/2010
Data are inadequate to derive an inhalation unit risk.

Provisional Peer-Reviewed Toxicity Values (PPRTVs)