Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:2:p5
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 2 (pt 5/6)
Character Range: 2412651–2415673

WHO and RIVM as it was of longer duration and associated with drinking water administration (note that phenol exhibited a higher degree of toxicity when given by stomach tube/gavage than when administered via drinking water).
                      TC = 0.035 mg/m3          Inhalation value derived on the basis of a LOAEL of 21 mg/m3 (same as identified by EC 2006) associated with potential liver effects in occupationally exposed workersand an uncertainty factor of 600. It is note that the review undertaken considers that the critical effect associated with inhalation exposures to phenol is likely to be its mutagenic potential, and a non-threshold approach may be appropriate, however no evaluations are available. Also noted that despite significant limitations in the available data, it appears that phenol has more toxicity potential via inhalation than when ingested.
ATSDR (2008)          No chronic MRL derived    Oral MRL based on a LOAEL of 1 mg/kg/day associated thyroid effects in mink, and an uncertainty factor of 1000 (same study as considered by RIVM).
US EPA (2002)         RfD = 0.3 mg/kg/day       RfD (last reviewed in 2002) based on a benchmark dose approach where a BMDL of 93 mg/kg/day associated with decreased maternal weight gain in a short duration developmental rat study was derived, and an uncertainty factor of 300 considered.
                                                The previous evaluation by the US EPA considered an oral RfD of 0.6 mg/kg/day, adopted in the derivation of the current HIL (Turczynowicz 1993).

While a number of limitations have been identified by the UK review of the available data with respect to the quantification of phenol toxicity (UK EA 2009), the oral value recommended is based on the most recent review where a number of the database deficiencies have been more fully reviewed. This value has been adopted in the derivation of soil HILs.

Few inhalation values are available, and hence the threshold value derived by the UK (UK EA 2009) is recommended as it is based on a more recent review. As inhalation exposures appear to be more toxic than oral exposures the consideration of separate toxicity values for oral and inhalation routes of exposure (even if the inhalation route of exposure is not as significant for the characterisation of contaminated soil issues) is appropriate.

    2.4.3         Recommendation
On the basis of the discussion above, the following toxicity reference values (TRVs) have been adopted for phenol in the derivation of HILs:

2.5              Calculated HILs
On the basis of the above the following HILs have been derived for phenol (refer to Appendix B for equations used to calculate the HILs and Appendix C for calculations):
HIL Scenario            HIL (mg/kg)                      Percentage Contribution from Exposure Pathways
Ingestion of Soil/Dust  Ingestion of Home-grown Produce  Dermal Absorption of Soil/Dust                  Inhalation (dust)
Residential A           3000                             4