1,4-Dioxane

123-91-1

Diethylene ether; 1,4-Diethylene dioxide; 1,4-Dioxacyclohexane; Diethylene oxide; dioxyethylene ether; dioxane; p-Dioxane; [6]-crown-2

Solvent, dehydrating agent; stabilizer in chlorinated solvents

Last CHHSL revision:	1/2005
CHHSL Comments:	For chemical-specific screening levels for use in assessing contaminated sites, please see HHRA Note 3 (DTSC HERO). https://www.dtsc.ca.gov/assessingrisk/humanrisk2.cfm

Inhalation Unit Risk (μg/cubic meter)-1:	7.7 E-6
Inhalation Slope Factor (mg/kg-day)-1:	2.7 E-2
Oral Slope Factor (mg/kg-day)-1:	2.7 E-2
Comments/References:	OEHHA 2009. Air Toxics Hot Spots Program Technical Support Document for Cancer Potencies. Appendix B. Chemical-specific summaries of the information used to derive unit risk and cancer potency values. Updated 2011.

Acute REL (μg/m3):	3000
Species:	Human
Acute REL Toxicologic Endpoint:	Respiratory and eye irritation
Acute REL Target Organs:	Respiratory system, eyes
Severity:	Mild
Last Acute REL Revision:	1999
Acute Reference Exposure Levels Comments:	OEHHA 2008. Technical Supporting Document for Noncancer RELs, Appendix D2.

Chronic Inhalation REL (μg/m3):	3000
Chronic Target Organs:	Alimentary system, kidney, cardiovascular system
Human Data:	No
Last Chronic REL Revision:	2000
Chronic Reference Exposure Levels Comments:	OEHHA 2008. Technical Supporting Document for Noncancer RELs, Appendix D3

Cancer:	Currently listed

Cancer - Listing Mechanism

State's Qualified Experts

Listed as causing :	Listed as causing: Cancer
Date of Listing:	01/01/1988

No Significant Risk Level (NSRL)

30 µg/day

Cancer

Notification Level (μg/L):	1
Notification Level - Download:	pal14dioxan.pdf
California PHG Comments:	Notification Level updated in 2010. Documentation available from the Waterboard at https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/documents/notificationlevels/notification_levels_response_levels_overview.pdf