Immediately Dangerous To Life or Health (IDLH) Values

May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
A1 confirmed human carcinogen (ACGIH)
A2 suspected human carcinogen (ACGIH)
A3 animal carcinogen (ACGIH)
A4 not classifiable as a human carcinogen (ACGIH)
A5 not suspected as a human carcinogen (ACGIH)
ACGIH American Conference of Governmental Industrial Hygienists
AIHA American Industrial Hygiene Association
CAS Chemical Abstract Service
CF correction factor for LC data
CFR Code of Federal Regulations
EEGL emergency exposure guidance level (NRC)
ERPG emergency response planning guideline (AIHA)
IDLH immediately dangerous to life or health concentration value
i.p. intraperitoneal
i.v. intravenous
kg kilogram
LC lethal concentration
LC50 concentration causing death in 50%
LCLo lowest concentration causing death
LD lethal dose
LD50 dosage causing death in 50%
LDLo lowest dosage causing death
LEL lower explosive limit
mg/kg milligrams per kilogram of body weight
mg/m3 milligrams per cubic meter of air
mmHg millimeters of mercury (pressure measurement)
mppcf millions of particles per cubic foot of air
NIOSH National Institute for Occupational Safety and Health
NRC National Research Council
OSHA Occupational Safety and Health Administration
PEL permissible exposure limit (OSHA)
ppm parts per million parts of air
RD50 concentration producing a 50% decrease in respiratory rate following a 10-minute exposure
REL recommended exposure limit (NIOSH)
s.c. subcutaneous
SCP Standards Completion Program (NIOSH/OSHA)
SPEGL short-term public emergency guidance level (NRC)
STEL Short-term exposure limit
TCLo lowest concentration resulting in a toxic effect
TDLo lowest dose resulting in a toxic effect
TLV threshold limit value (ACGIH)
TWA time-weighted average
Page last reviewed: December 4, 2014 (archived document)