Benzo[a]pyrene laser cleaning visualization showing process effects
Ikmanda Roswati
Ikmanda RoswatiPh.D.Indonesia
Ultrafast Laser Physics and Material Interactions
Published
Jan 6, 2026

Benzo[a]pyrene Compound

Benzoapyrene Compound safety information for laser cleaning. Health hazards, exposure limits, and protective equipment requirements.

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
Detection Monitoring
SensorTypes
  • Particulate monitors (PM2.5/PM10)
  • Area air sampling
  • Personal air sampling pumps
DetectionRange
0.001-10 mg/m³
AlarmSetpoints
Low
0.1 mg/m³ (NIOSH REL)
High
0.2 mg/m³ (OSHA PEL)
Evacuate
80 mg/m³ (NIOSH IDLH)
ColorimetricTubes
Not available - laboratory analysis required
AnalyticalMethods
MethodTechniqueDetectionLimit
NIOSH 5506HPLC with fluorescence detection0.2 ng/sample
EPA Method 8310HPLC or GC-MSSub-ppb levels
OSHA Method 58GC with FID0.1 µg/sample
OdorThreshold
Not applicable - no characteristic warning odor at hazardous levels
Environmental Impact
AquaticToxicity
Very toxic to aquatic organisms. LC50 (fathead minnow, 96h): 3.7 µg/L. Bioaccumulates in fish - BCF 1,100-15,000.
Biodegradability
Poorly biodegradable. Degradation half-life in soil: months to years. Resistant to microbial breakdown.
Bioaccumulation
High bioaccumulation potential. Log Kow: 6.04-6.50. Accumulates in fatty tissues and sediments.
SoilMobility
Low mobility. Strongly adsorbs to soil/sediment organic matter. Persistent in contaminated sites.
AtmosphericFate
Primarily bound to particulate matter. Photolyzes slowly under UV light. Atmospheric half-life: hours to days on particles.
OzoneDepletion
false
ReportableReleases
Water
1 lb to navigable waters - reportable to NRC
Air
1 lb/day - reportable to EPA (CERCLA RQ)
Ppe Requirements
Respiratory
NIOSH-approved air-purifying respirator with P100 particulate filters for <0.2 mg/m³. SCBA for unknown concentrations or emergency response.
Eye Protection
Chemical safety goggles, face shield for dusty operations
Skin Protection
Nitrile or butyl rubber gloves, chemical-resistant clothing. PAHs absorb through skin - double gloving recommended for prolonged exposure.
Reactivity
Stability
Stable under normal conditions. Light-sensitive. Decomposes at high temperatures.
Polymerization
Will not polymerize
IncompatibleMaterials
  • Strong oxidizers (nitric acid, peroxides)
  • Strong acids
  • Halogens
HazardousDecomposition
  • Carbon monoxide
  • Carbon dioxide
  • Toxic PAH compounds
  • Polycyclic aromatic hydrocarbons
ConditionsToAvoid
  • Heat
  • Flames
  • Light
  • Oxidizers
ReactivityHazard
May react with strong oxidizers. Generally stable but avoid high heat.
Regulatory Classification
UnNumber
UN3077 (Environmentally hazardous substance, solid, n.o.s.)
DotHazardClass
9 (Miscellaneous)
DotLabel
Class 9
NfpaCodes
Health
2
Flammability
1
Reactivity
0
Instability
0
EpaHazardCategories
  • Carcinogenicity
  • Aquatic toxicity
  • Persistence
  • Bioaccumulation
SaraTitleIii
true
CerclaRq
1 pound (0.454 kg)
RcraCode
U022

Contaminants That Produce Benzo[a]pyrene

Benzo[a]pyrene is produced as a gaseous or particulate byproduct during laser ablation of contaminated surfaces. The generation rate and chemical form depend on the source contaminant and substrate combination. Proper exhaust ventilation and gas monitoring ensure safe working concentrations in laser cleaning enclosures.
No metadata available

Bitumen and Tar Coatings

No metadata available

Carbon Deposit Buildup

No metadata available

Carbon Soot Deposits

No metadata available

Fire and Smoke Damage

No metadata available

Rubber Compound Residue

Chemical Properties

Molecular formula, CAS number, molecular weight, and chemical structure
Type
chemical_properties
Id
benzoapyrene-physical-data

Physical Properties

Chemical and physical characteristics
BoilingPoint
496°C (925°F) - decomposes
MeltingPoint
178.1°C (352.6°F)
VaporPressure
5.5 × 10⁻⁹ mmHg @ 25°C (negligible)
VaporDensity
Not applicable (solid)
SpecificGravity
1.35
FlashPoint
Not determined
AutoignitionTemp
Not determined
ExplosiveLimits
Not applicable
Appearance
Pale yellow to tan crystalline solid, needles or plates
Odor
Faint aromatic odor

Alternative Names

Synonyms and chemical identifiers
Synonyms
  • B[a]P
  • BaP
  • Benzo(a)pyrene
  • 3,4-Benzopyrene
  • Benzo[def]chrysene
CommonTradeNames
    OtherIdentifiers
    RtecsNumber
    DJ3675000
    EcNumber
    200-028-5
    PubchemCid
    2336

    Health Effects

    Adverse health impacts from exposure to this compound
    Route
    inhalation
    Effect
    Respiratory tract irritation and increased risk of lung cancer
    Severity
    severe
    Onset
    long-term
    Route
    skin_contact
    Effect
    Skin irritation and increased risk of skin cancer
    Severity
    severe
    Onset
    long-term
    Route
    eye_contact
    Effect
    Eye irritation and conjunctivitis
    Severity
    moderate
    Onset
    immediate
    Route
    ingestion
    Effect
    Gastrointestinal irritation and systemic carcinogenic effects
    Severity
    severe
    Onset
    long-term

    Personal Protective Equipment

    Required safety equipment for handling this compound
    Respiratory
    NIOSH-approved air-purifying respirator with P100 particulate filters for <0.2 mg/m³. SCBA for unknown concentrations or emergency response.
    Skin
    Nitrile or butyl rubber gloves, chemical-resistant clothing. PAHs absorb through skin - double gloving recommended for prolonged exposure.
    Eye
    Chemical safety goggles, face shield for dusty operations
    MinimumLevel
    Level C for known concentrations <0.2 mg/m³, Level B for unknown or >0.2 mg/m³
    SpecialNotes
    PAH is carcinogenic - minimize skin contact. Decontaminate immediately after exposure. Disposable protective clothing recommended for heavy contamination.

    Exposure Limits

    OSHA, NIOSH, and ACGIH exposure thresholds
    WorkplaceExposure
    OshaPel
    twa8Hr: null
    stel15Min: null
    ceiling: null
    NioshRel
    twa8Hr: null
    stel15Min: null
    ceiling: null
    idlh: 80 mg/m³ (as coal tar pitch volatiles)
    AcgihTlv
    twa8Hr: null
    stel15Min: null
    ceiling: null
    BiologicalExposureIndices
    0: [object Object]
    1: [object Object]

    Storage Requirements

    Safe storage conditions and compatibility
    TemperatureRange
    Store at room temperature, avoid excessive heat >30°C
    Ventilation
    Local exhaust ventilation to control dust. Store in well-ventilated area.
    Incompatibilities
    • Strong oxidizers
    • Strong acids
    • Halogens
    ContainerMaterial
    Tightly sealed glass or plastic containers. Store away from light.
    Segregation
    Separate from oxidizers and incompatibles. Designated carcinogen storage area.
    QuantityLimits
    Minimize quantities. Follow institutional carcinogen storage protocols.
    SpecialRequirements
    Post "CANCER HAZARD" signs. Restrict access to authorized trained personnel only. Secondary containment required. Inspect containers regularly for integrity.

    Emergency Response

    Procedures for spills, exposure, and incidents
    FireHazard
    Combustible solid. May burn in sustained fire. Produces carcinogenic PAH compounds in smoke.
    FireSuppression
    Dry chemical, CO2, water spray, foam. Wear SCBA - toxic combustion products. Contain runoff.
    SpillProcedures
    Avoid generating dust. Sweep/vacuum with HEPA filter. Place in sealed containers. DO NOT wash down drains - PAH contamination persists. Dispose as hazardous waste.
    ExposureImmediateActions
    Remove contaminated clothing immediately. Wash skin thoroughly with soap and water. Do not use solvents on skin. If inhaled, move to fresh air. Seek medical attention - inform physician of carcinogen exposure.
    EnvironmentalHazards
    Very toxic to aquatic life. Persists in environment (soil/sediment for years). Bioaccumulates in food chain. Report spills >1 lb.
    SpecialHazards
    KNOWN HUMAN CARCINOGEN (IARC Group 1). Causes lung cancer, skin cancer, leukemia. Mutagenic and teratogenic. PAH exposure linked to multiple cancers. Contaminated soil requires remediation.

    Regulatory Classification

    DOT, UN, and NFPA hazard classifications
    UnNumber
    UN3077 (Environmentally hazardous substance, solid, n.o.s.)
    DotHazardClass
    9 (Miscellaneous)
    DotLabel
    Class 9
    NfpaCodes
    Health
    2
    Flammability
    1
    Reactivity
    0
    Special
    null
    Instability
    0
    EpaHazardCategories
    • Carcinogenicity
    • Aquatic toxicity
    • Persistence
    • Bioaccumulation
    SaraTitleIii
    true
    CerclaRq
    1 pound (0.454 kg)
    RcraCode
    U022

    Environmental Impact

    Toxicity, biodegradability, and environmental fate
    AquaticToxicity
    Very toxic to aquatic organisms. LC50 (fathead minnow, 96h): 3.7 µg/L. Bioaccumulates in fish - BCF 1,100-15,000.
    Biodegradability
    Poorly biodegradable. Degradation half-life in soil: months to years. Resistant to microbial breakdown.
    Bioaccumulation
    High bioaccumulation potential. Log Kow: 6.04-6.50. Accumulates in fatty tissues and sediments.
    SoilMobility
    Low mobility. Strongly adsorbs to soil/sediment organic matter. Persistent in contaminated sites.
    AtmosphericFate
    Primarily bound to particulate matter. Photolyzes slowly under UV light. Atmospheric half-life: hours to days on particles.
    OzoneDepletion
    false
    ReportableReleases
    Water
    1 lb to navigable waters - reportable to NRC
    Air
    1 lb/day - reportable to EPA (CERCLA RQ)

    FAQ

    Common Questions and Answers
    What personal protective equipment (PPE) is essential for operators during laser cleaning to minimize Benzo[a]pyrene exposure?
    Always wear a full-body Tyvek suit or equivalent impermeable coverall, nitrile gloves, and safety goggles to prevent skin contact with airborne particles or residues from laser-ablated surfaces. Use a powered air-purifying respirator (PAPR) with organic vapor cartridges rated for PAHs to protect against inhalation, as Benzo[a]pyrene can persist in the air after cleaning. Change PPE after each session and decontaminate equipment to avoid secondary exposure.

    Detection & Monitoring

    Methods for detecting and measuring this compound
    SensorTypes
    • Particulate monitors (PM2.5/PM10)
    • Area air sampling
    • Personal air sampling pumps
    DetectionRange
    0.001-10 mg/m³
    AlarmSetpoints
    Low
    0.1 mg/m³ (NIOSH REL)
    High
    0.2 mg/m³ (OSHA PEL)
    Evacuate
    80 mg/m³ (NIOSH IDLH)
    ColorimetricTubes
    Not available - laboratory analysis required
    AnalyticalMethods
    • [object Object]
    • [object Object]
    • [object Object]
    OdorThreshold
    Not applicable - no characteristic warning odor at hazardous levels

    Reactivity

    Chemical reactivity and incompatibilities
    Stability
    Stable under normal conditions. Light-sensitive. Decomposes at high temperatures.
    Polymerization
    Will not polymerize
    IncompatibleMaterials
    • Strong oxidizers (nitric acid, peroxides)
    • Strong acids
    • Halogens
    HazardousDecomposition
    • Carbon monoxide
    • Carbon dioxide
    • Toxic PAH compounds
    • Polycyclic aromatic hydrocarbons
    ConditionsToAvoid
    • Heat
    • Flames
    • Light
    • Oxidizers
    ReactivityHazard
    May react with strong oxidizers. Generally stable but avoid high heat.

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