Soil Generic Assessment Criteria for Human Health Risk ... - ESdat

www.esdat.net Esdat Environmental Database Management Software +61 2 8875 7948
Dichloromethane CAS Number: 75-09-2
Assessor A: Nick Brown, Grontmij Assessor B Catherine Helm, WD Final Review:
Panel/SF
Environmental
Date 26/05/2009 Date 01-Jun-09 Date 28/08/2009
ID inhal Recommended IDinhal Units
Justification
Human studies are considered generally inadequate to demonstrate whether or not DCM is carcinogenic, however, carcinogenicity has been demonstrated in mice and
to a lesser extent in female rats. IRIS provides the carcinogenic Classification —B2; probable human carcinogen. IARC classified dichloromethane as possibly
carcinogenic to humans (Group 2B), based on inadequate evidence for the carcinogenicity of dichloromethane in humans and sufficient evidence for the
carcinogenicity of dichloromethane in experimental animals. Health Canada classified dichloromethane as "probably carcinogenic to humans" (Group II) and has
generated PBEK modified TD05 values (5% incidence of tumours). IRIS has also quantified carcinogenic risk by predicting concentrations equivalent to increased cancer
risk of E-5. In relation to the tendency for tumor development in mice through exposure to DCM by inhalation, TERA comment that; "there are clear species
differences in the putatively carcinogenic pathway of metabolism of dichloromethane which are consistent with the hypothesis that humans are likely to be less
sensitive than some species of experimental animals in this regard". RIVM determined that dichloromethane is not considered to be genotoxic to humans, and
therefore, derived risk values based on a threshold approach. Threshold based HCVs are also provided by ATSDR and WHO.
N/A
ug.kg-1.d-1
In view of the uncertainty remaining in relation to the actual carcinogenicity of DCM to humans and uncertainty relating to the methods of quantification of nonthreshold
risk, particularly in view of the guidance provided within SR2, the selection of conservative TDIs is considered more appropriate at this stage than the
derivation Index Doses.
Organisation Web Link Last Updated Date Web Checked Non threshold
effects
Health Canada Toxicological Values http://www.hc-sc.gc.ca/index_e.html 27/05/2009 Yes TD05s 2238 mg/m3 Not appropriate
to derive a clear
value from a
TD05. See below
for TERA
conversion of
TD05 to
1:100,000
increased cancer
risk
Basis
Health criteria
type
Value
Units
Confidence rating
Basis
5% increase in tumor
incidence (PBEK
modified TD05)
USEPA Integrated Risk Information System
(IRIS)
http://epa.gov/iris/ 02/04/2009 Yes Predicted
concentration
equivalent to
carcinogenic risk
of E-5
20 ug/m3 5.714 Extrapolation Method —
Linearized multistage
procedure, extra risk
TOXNET 2 http://toxnet.nlm.nih.gov/ 02/04/2009 Yes Predicted
concentration
equivalent to
carcinogenic risk
of E-5
0.44 mg/m3 126 Conversion of Health
Canada TD05 to
1:100,000 increased
cancer risk by TERA
Page 5 of 6 EIC Proforma dichloromethane.xls 28/08/2009