Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:4:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 4 (pt 3/4)
Character Range: 2439657–2443018

toxicity values are available, however the following are available from Level 1 Australian and International sources:

Source              Value                    Basis/Comments
Australian
ADWG                No evaluation available
OCS (2012)          No evaluation available
International
WHO (1995)          ADI = 0.17 mg/kg/day     ADI derived by WHO (1995) on a NOAEL of 50 mg/kg/day from a sub-chronic study and a 300-fold uncertainty factor (which included an additional 10 fold factor to address the lack of chronic studies and possible genotoxic and promoting activity).
RIVM (2001)         TDI = 0.05 mg/kg/day     TDI based on a 90-day sub-chronic oral study.
                    TC = 0.17 mg/m3          TC based on route extrapolation from oral data.
OEHHA (2009)        REL = 0.6 mg/m3          Chronic REL based on route extrapolation of the LOAEL and NOAEL derived from the study used to derive the current US EPA RfD for 2- and 3-methylphenol.
ATSDR (2008)        MRL = 0.1 mg/kg/day      Oral MRL based on a LOAEL associated with increased incidences of bronchiole hyperplasia of the lung and follicular degeneration of the thyroid gland from a 2-year dietary study in female mice (NTP 2008).
US EPA (IRIS 2012)  RfD = 0.05 mg/kg/day     RfD (last reviewed in 1988) derived for 2- and 3-methylphenol based on decreased body weights and neurotoxicity in a 90-day sub-chronic study in rats.

The threshold value derived by ATSDR (2008) is based on a chronic study not available at the time when the WHO (1995), RIVM (2001) or US EPA conducted their review (where threshold values were derived on the basis of sub-chronic studies). On this basis, the oral value (taken as an ADI) available from ATSDR (2008) is considered the most current and robust value for deriving a soil HIL.

No dermal or inhalation specific studies or data are available. For the presence of cresols in soil, it is considered appropriate to consider use of the available ADI for all pathways of exposures.

    4.4.3         Recommendation
On the basis of the discussion above, the following toxicity reference values (TRVs) have been adopted for cresols (as sum of all isomers) in the derivation of HILs:

4.5              Calculated HILs
On the basis of the above, the following HILs have been derived for cresols (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           400                              5                                               89                 6   <1
Residential B           4700                             16                                              --                 84  <1
Recreational C          4000                             27                                              --                 73  <1
Commercial D            25 000                           12                                              --                 88  <1

-- Pathway not included in derivation of HIL

4.6              References
ATSDR 2008, Toxicological profile for Cresols, Agency for Toxic Substances and Disease Registry U.S. Department of Health and Human