Ethylbenzene
Chronic Inhalation REL (μg/m3)
2000
Chronic Target Organs
Development; alimentary system (liver); kidney; endocrine system
Human Data
No
Last Chronic REL Revision
2000
Chronic Reference Exposure Levels Comments
%1
Ethylene Glycol Monobutyl Ether
Acute REL (μg/m3)
4700
Species
Human
Acute REL Toxicologic Endpoint
Respiratory and eye irritation
Acute REL Target Organs
Respiratory system, eyes
8-Hour Inhalation REL (μg/m3)
164
Last 8-Hour REL Revision
05/04/2018
Chronic Inhalation REL (μg/m3)
82
Chronic Reference Exposure Levels Comments
8-Hour Reference Exposure Levels Comments
Acute Reference Exposure Levels Comments
Severity
Mild
Last Acute REL Revision
2018
Beryllium Oxide
Chronic Inhalation REL (μg/m3)
0.007 (inhalation); 2.0 μg/kg BW-day (oral)
Chronic Target Organs
Inhalation: Respiratory system, immune system. Oral: Alimentary system (gastrointestinal tract)
Human Data
Yes
Last Chronic REL Revision
2001
Chronic Reference Exposure Levels Comments
OEHHA 2008. Technical Supporting Document for Noncancer RELs, Appendix D3. Listed as Beryllium & beryllium compounds.
Oleum
Acute REL (μg/m3)
120
Species
Human
Acute REL Toxicologic Endpoint
Respiratory irritation
Acute REL Target Organs
Respiratory system
Acute Reference Exposure Levels Comments
Severity
Mild
Last Acute REL Revision
1999
Acrolein
Acute REL (μg/m3)
2.5
Species
Human
Acute REL Toxicologic Endpoint
Respiratory and eye irritation
Acute REL Target Organs
Respiratory system, eyes
8-Hour Inhalation REL (μg/m3)
0.7
Last 8-Hour REL Revision
2008
Chronic Inhalation REL (μg/m3)
0.35
Chronic Target Organs
Respiratory system
Human Data
No
Last Chronic REL Revision
2008
Chronic Reference Exposure Levels Comments
8-Hour Reference Exposure Levels Comments
Acute Reference Exposure Levels Comments
Sensory irritancy is the critical response to acute acrolein exposure. For this effect both the Darley and Weber-Tschopp studies found similar effect levels resulting in similar estimates for the acute REL. In consideration of this, we took the geometric mean of the REL values from these studies to derive the acute REL of 2.5 _g/m3 (1.1 ppb).
OEHHA 2008. Technical Supporting Document for Noncancer RELs, Appendix D1. Updated July 2014.
Typo in the Acrolein REL documentation – for the Haber’s Law adjustment, Section 5.4.1 (Concentration and Time Extrapolation using Haber’s Law) corrected in this update.
Severity
Mild
Last Acute REL Revision
2008
Sodium Hydroxide
Acute REL (μg/m3)
8
Species
Human
Acute REL Toxicologic Endpoint
Skin, eye, and respiratory irritation
Acute REL Target Organs
Eyes; skin; respiratory system
Acute Reference Exposure Levels Comments
Severity
mild
Last Acute REL Revision
1999
Ethylene Glycol Monomethyl Ether Acetate
Chronic Inhalation REL (μg/m3)
90
Chronic Target Organs
Reproductive system
Human Data
No
Last Chronic REL Revision
2000
Chronic Reference Exposure Levels Comments
1,3-Butadiene
Acute REL (μg/m3)
660
Species
Mouse
Acute REL Toxicologic Endpoint
Development (low male fetal weight)
Acute REL Target Organs
Development
8-Hour Inhalation REL (μg/m3)
9
Last 8-Hour REL Revision
2013
Chronic Inhalation REL (μg/m3)
2
Chronic Target Organs
Reproductive system
Human Data
No
Last Chronic REL Revision
2013
Chronic Reference Exposure Levels Comments
8-Hour Reference Exposure Levels Comments
OEHHA 2013. Technical Support Document for Noncancer RELs, Appendix D1. Updated July 2014.
Acute Reference Exposure Levels Comments
Severity
Severe
Last Acute REL Revision
2013
Beryllium Sulfate
Chronic Inhalation REL (μg/m3)
0.007 (inhalation); 2.0 μg/kg BW-day (oral)
Chronic Target Organs
Inhalation: Respiratory system, immune system. Oral: Alimentary system (gastrointestinal tract)
Human Data
Yes
Last Chronic REL Revision
2001
Chronic Reference Exposure Levels Comments
OEHHA 2008. Technical Supporting Document for Noncancer RELs, Appendix D3. Listed as Beryllium & beryllium compounds.
Ethylene Glycol Monomethyl Ether
Acute REL (μg/m3)
93
Species
Rat
Acute REL Toxicologic Endpoint
Reproductive/ Development (teratogenic effects)
Acute REL Target Organs
Reproductive/ Development
Chronic Inhalation REL (μg/m3)
60
Chronic Target Organs
Reproductive system
Human Data
No
Last Chronic REL Revision
2000
Chronic Reference Exposure Levels Comments
Acute Reference Exposure Levels Comments
Severity
Severe
Last Acute REL Revision
1999