Substance Specific ChemicalsOSHA Requirements
Permissible Exposure Limits Substance Specific • There are OSHA Permissible Exposure Limits (PELs) for 470 chemicals, but only 28 have substance specific standards • Most are carcinogens or present other serious health hazards • Detailed requirements within each standard for compliance
List of Chemicals • Asbestos • Alpha-Napththylamine • 3,3-Dichlorobenzidine • Beta-Napthylamine • 4-Aminodiphenyl • Beta-Propiolactone • 4-Dimethylaminoazobenzene • Vinyl chloride • Lead • Benzene • Cotton dust • Acrylonitrile • Formaldehyde • 4-Nitrobiphenyl
List of Chemicals • Methyl chloromethyl ether • Bis-Chloromethyl ether • Benzidine • Ethyleneimine • 1,2-Dibromo-3-chloropropane • 2-Acetylaminofluorene • N-Nitrosodimethylamine • Inorganic Arsenic • Cadmium • Coke oven emissions • Ethylene oxide • Methylenedianiline • 1,2-Butadiene • Methylene Chloride
Substance Specific These standards typically specify: • Action Level (usually one-half of the 8-hr PEL) • Exposure monitoring • Medical surveillance- may require specific tests • Information and training • Written compliance plans • Respiratory protection/PPE • Hygiene facilities and practices • Establishment of regulated areas
Specific Chemicals • Benzene • 29 CFR 1910.1028 • Inorganic Arsenic • 29 CFR 1910.1018 • Lead • 29 CFR 1910.1025; • 29 CFR 1926.62 • Vinyl Chloride • 29 CFR 1910.1017 • Hydrogen Sulfide
Benzene • Permissible Exposure Limit (PEL) is 1 ppm (8-hr Time Weighted Average (TWA); Short Term Exposure Limit (STEL) = 5 ppm “skin” • Action Level is below typical PID sensitivity • Colorless liquid with sweet aromatic odor • Poor warning properties: mean odor threshold is 34 ppm
Benzene • Flammable liquid • Typically found combined with other petroleum hydrocarbons • Air monitoring options include: • Benzene specific instruments such as theUltraRae Benzene PGM-7200 • Detector tubes (e.g. Draeger) • Sample media for laboratory analysis
Benzene Health Hazards • Target organs: • Blood forming systems, bone marrow • Central nervous system • Eyes, skin, respiratory system
Benzene Exposure Symptoms • Acute exposure: • Breathless, irritable, giddy, headache, dizzy, nausea • Eye, nose, respiratory tract irritation • Convulsion/coma from severe exposure • Skin blistering • Chronic exposure: • Leukemia • Aplastic anemia • Dermatitis
Benzene Medical Exams • Medical surveillance for: • > Action Level 30 days per year • > PEL 10 days per year • Emergency exposure • If blood chemistry indicate benzene impacts • Referral for specialized exams • Extensive protocols for removal/job protection
Inorganic Arsenic • PEL = 10 µg/M3 (0.01 mg/m3) • Action Level = 5 µg/M3 (.005 mg/m3) • Properties vary by compound • Most commonly found at former pesticide sites • Arsenic air monitoring requires a sampling pump, media, and laboratory analysis. Total dust/respirator dust monitoring is useful after the ratio of arsenic to total dust is known.
Inorganic Arsenic • Target Organs • Skin • Respiratory system • Kidney, liver, GI tract • Central nervous system • Possible fetal effects
Inorganic Arsenic Symptoms • Acute exposure: • Poisoning by inhalation is rare • Chronic exposure: • Dermatitis, ulcerations to skin/nasal septum • Weakness • Loss of appetite • Nausea, vomiting, diarrhea • Cancer (skin, lung, possibly liver)
Lead • Two lead substance-specific standards • General Industry – 29 CFR 1910.1025 • Construction – 29 CFR 1926.62 • URS often involved with construction version • Applies to remediation, verses investigation • Removal of lead-impacted soils • Lead-based paint work; demolition activities
Lead • OSHA PEL is 0.050 mg/M3 (50 µg/M3) as TWA • Action Level is 0.030 mg/M3 (30 µg/M3) as TWA • Air monitoring requires sampling pump, filter media, and laboratory analysis. XRF lead paint instruments provide real time measurement of lead content in paint, but not airborne concentrations.
Lead Health Hazards • Target Organs • GI tract • Central nervous system • Kidneys • Blood • Gingival tissue • Reproductive system • Acute exposure: • Gastroenteritis • Chronic exposure: • Anemia, constipation, abdominal pain • Peripheral nerve damage (wrist/ankle drop) • Colic • Gum lead line • Fetal neural impacts • Lead accumulates in the body
Lead Requirements • One of the more stringent standards: • Blood lead determination prior to job; periodic • Mandatory minimum Level C PPE • Regulated work areas • Shower and change facilities • Exposure monitoring • Some exceptions; check with your Regional HSE Manager
Vinyl Chloride • PEL = 1 ppm • Action Level = 0.5 ppm • Colorless liquid/gas with faint odor • High vapor pressure/vapor density • Extreme fire/explosive hazard • Incompatible with oxidizers, copper, aluminum, iron, steel • Typically found in landfill gases as a by-product of chlorinated solvent degradation • Air monitoring requires sample pump, filter media, and laboratory analysis or detector tubes
Vinyl Chloride Health Hazards • Routes of entry • Respiratory • Ingestion – personal hygiene is very important • Target Organs • Liver (carcinogen) • Central nervous system • Blood • Respiratory system • Lymphatic system • Possible reproductive system
Vinyl Chloride Symptoms • Acute Exposure • Frostbite on liquid contact • Low toxicity by inhalation • Chronic Exposure: • Sluggishness • Abdominal pain • Gastrointestinal bleeding • Enlarged liver • Pallor or blueness of extremities • Liver cancer
Vinyl Chloride Medical Surveillance • Any employee exposed >0.5 ppm Action Level will be provided the opportunity for exams/testing • Provided at time of initial assignment, or upon beginning medical surveillance, or as a result of emergency exposure • General physical exam/medical history with specific attention to: • Detecting enlargement/dysfunction of the liver, spleen or kidneys • Abnormalities in skin, connective tissues, or pulmonary system • Written physician’s statement of findings, including opinion regarding use of PPE and respirators
Hydrogen Sulfide • OSHA PEL = 10 ppm; 20 ppm ceiling • California STEL = 15 ppm (15 minutes) • Dense, low-lying gas • High vapor pressure (>17 atm) • Fire/explosion hazard • Potential exposure sources include sewers, landfills, and petroleum refining, paper/pulp mills
Hydrogen Sulfide Hydrogen Sulfide gas: • Smells like rotten eggs • Most people can detect it at 0.008ppm • Odor is not a reliable indicator of hazard • Sense of smell can become fatigued; increasing levels may no longer be detectable without instruments • Air monitoring options include H2S specific monitors as part of most four-gas confined space monitoring units, and detection tubes
H2S Health Hazards • Acute Exposures: • Respiratory paralysis (chemical asphyxiate) leading to unconsciousness and death • At lower concentrations: • Headache, dizziness, upset stomach • Eye effects at exposures slightly above PEL
Hydrogen Sulfide • Each person should have own H2S detector • Wear it on belt, pants, or chest (never on hardhat) • Detector must have audible alarm at 10 ppm • Dual audible/vibration alarm is preferred • If alarm sounds, notify others and evacuate
