Ikmanda Roswati
Ikmanda RoswatiPh.D.Indonesia
Ultrafast Laser Physics and Material Interactions
Published
Dec 24, 2025

Benzo[a]pyrene (C₂₀H₁₂)

Chemical Properties

Chemical Identity

CAS Number
50-32-8
Formula
C₂₀H₁₂
Molecular Weight
252.31 g/mol

Exposure Limits Comparison

Health Effects

Lung Cancer
Yes
Skin Cancer
Yes
DNA Damage
Yes
Immunosuppression
Yes
Developmental Toxicity
Yes

Benzo[a]pyrene (C₂₀H₁₂) safety information

Comprehensive safety and handling requirements

Detection Monitoring
Sensor Types
  • Particulate monitors (PM2.5/PM10)
  • Area air sampling
  • Personal air sampling pumps
Detection Range0.001-10 mg/m³
Alarm Setpoints
Low0.1 mg/m³ (NIOSH REL)
High0.2 mg/m³ (OSHA PEL)
Evacuate80 mg/m³ (NIOSH IDLH)
Colorimetric TubesNot available - laboratory analysis required
Analytical Methods
MethodTechniqueDetection Limit
NIOSH 5506HPLC with fluorescence detection0.2 ng/sample
EPA Method 8310HPLC or GC-MSSub-ppb levels
OSHA Method 58GC with FID0.1 µg/sample
Odor ThresholdNot applicable - no characteristic warning odor at hazardous levels
Environmental Impact
Aquatic ToxicityVery toxic to aquatic organisms. LC50 (fathead minnow, 96h): 3.7 µg/L. Bioaccumulates in fish - BCF 1,100-15,000.
BiodegradabilityPoorly biodegradable. Degradation half-life in soil: months to years. Resistant to microbial breakdown.
BioaccumulationHigh bioaccumulation potential. Log Kow: 6.04-6.50. Accumulates in fatty tissues and sediments.
Soil MobilityLow mobility. Strongly adsorbs to soil/sediment organic matter. Persistent in contaminated sites.
Atmospheric FatePrimarily bound to particulate matter. Photolyzes slowly under UV light. Atmospheric half-life: hours to days on particles.
Ozone Depletionfalse
Reportable Releases
Water1 lb to navigable waters - reportable to NRC
Air1 lb/day - reportable to EPA (CERCLA RQ)
Ppe Requirements
RespiratoryNIOSH-approved air-purifying respirator with P100 particulate filters for <0.2 mg/m³. SCBA for unknown concentrations or emergency response.
Eye ProtectionChemical safety goggles, face shield for dusty operations
Skin ProtectionNitrile or butyl rubber gloves, chemical-resistant clothing. PAHs absorb through skin - double gloving recommended for prolonged exposure.
Reactivity
StabilityStable under normal conditions. Light-sensitive. Decomposes at high temperatures.
PolymerizationWill not polymerize
Incompatible Materials
  • Strong oxidizers (nitric acid, peroxides)
  • Strong acids
  • Halogens
Hazardous Decomposition
  • Carbon monoxide
  • Carbon dioxide
  • Toxic PAH compounds
  • Polycyclic aromatic hydrocarbons
Conditions To Avoid
  • Heat
  • Flames
  • Light
  • Oxidizers
Reactivity HazardMay react with strong oxidizers. Generally stable but avoid high heat.
Regulatory Classification
Un NumberUN3077 (Environmentally hazardous substance, solid, n.o.s.)
Dot Hazard Class9 (Miscellaneous)
Dot LabelClass 9
Nfpa Codes
Health3
Flammability1
Reactivity0
Epa Hazard Categories
  • Carcinogenicity
  • Aquatic toxicity
  • Persistence
  • Bioaccumulation
Sara Title Iiitrue
Cercla Rq1 pound (0.454 kg)
Rcra CodeU022
Storage Requirements
Temperature RangeStore at room temperature, avoid excessive heat >30°C
VentilationLocal exhaust ventilation to control dust. Store in well-ventilated area.
Incompatibilities
  • Strong oxidizers
  • Strong acids
  • Halogens
Container MaterialTightly sealed glass or plastic containers. Store away from light.
SegregationSeparate from oxidizers and incompatibles. Designated carcinogen storage area.
Quantity LimitsMinimize quantities. Follow institutional carcinogen storage protocols.
Special RequirementsPost "CANCER HAZARD" signs. Restrict access to authorized trained personnel only. Secondary containment required. Inspect containers regularly for integrity.

Produced From Contaminants

Z-Beam Logo
Z-Beam Logo
Z-Beam Logo
Z-Beam Logo
Z-Beam Logo

Exposure Limits

Regulatory exposure thresholds and safe concentration levels

Workplace Exposure
Osha Pel
twa_8hr: 0.2 mg/m³ (coal tar pitch volatiles)
stel_15min: null
ceiling: null
Niosh Rel
twa_8hr: 0.1 mg/m³ (coal tar pitch volatiles)
stel_15min: null
ceiling: null
idlh: 80 mg/m³ (as coal tar pitch volatiles)
Acgih Tlv
twa_8hr: 0.2 mg/m³ (inhalable fraction)
stel_15min: null
ceiling: null
Biological Exposure Indices
0: [object Object]
1: [object Object]

Physical Properties

Physical characteristics and state information

Boiling Point
496°C (925°F) - decomposes
Melting Point
178.1°C (352.6°F)
Vapor Pressure
5.5 × 10⁻⁹ mmHg @ 25°C (negligible)
Vapor Density
Not applicable (solid)
Specific Gravity
1.35
Flash Point
Not determined
Autoignition Temp
Not determined
Explosive Limits
Not applicable
Appearance
Pale yellow to tan crystalline solid, needles or plates
Odor
Faint aromatic odor

Reactivity

Chemical reactivity and compatibility with other substances

Stability
Stable under normal conditions. Light-sensitive. Decomposes at high temperatures.
Polymerization
Will not polymerize
Incompatible Materials
  • Strong oxidizers (nitric acid, peroxides)
  • Strong acids
  • Halogens
Hazardous Decomposition
  • Carbon monoxide
  • Carbon dioxide
  • Toxic PAH compounds
  • Polycyclic aromatic hydrocarbons
Conditions To Avoid
  • Heat
  • Flames
  • Light
  • Oxidizers
Reactivity Hazard
May react with strong oxidizers. Generally stable but avoid high heat.

Synonyms & Identifiers

Alternative names and chemical identifiers (CAS numbers)

Synonyms
  • B[a]P
  • BaP
  • Benzo(a)pyrene
  • 3,4-Benzopyrene
  • Benzo[def]chrysene
Common Trade Names
    Other Identifiers
    Rtecs Number
    DJ3675000
    Ec Number
    200-028-5
    Pubchem Cid
    2336