Nitrobenzene on your skin: a safety profile
Moderate riskTransdermal absorption of nitrobenzene is highly significant — OSHA's skin notation acknowledges that dermal contact is a major route of methemoglobin-inducing exposure, potentially exceeding inhalation in occupational settings where skin contact is uncontrolled. Dermal absorption kinetics: nitrobenzene is a lipophilic liquid (log P = 1.85) that penetrates intact skin readily; dermal absorption rate estimated at 0.3–2 mg/cm²/hr from liquid contact — a worker with hand/forearm immersion in liquid nitrobenzene could absorb a methemoglobin-inducing dose within minutes of unprotected contact. Historical occupational poisoning: mass methemoglobinemia poisoning from nitrobenzene dermal absorption has been documented in munitions workers (nitrobenzene used as intermediates in explosive synthesis) and aniline dye factory workers; exposures through contaminated clothing represent a sustained absorption source that continues after leaving the workplace. 'Oil of mirbane' soap exposure: nitrobenzene was widely used in inexpensive 'almond-scented' soaps and shoe polishes in the 19th and early 20th centuries — handwashing and shoe-polishing created regular dermal contact; pediatric and adult methemoglobinemia from these products is documented in historical toxicology literature. PPE: butyl rubber gloves provide the best protection against nitrobenzene dermal absorption; nitrile and neoprene offer moderate protection; decontamination with soap and water for any skin contact is essential. Monitoring: urinary p-nitrophenol (primary metabolite) and blood MetHgb % are the key biological exposure indices for nitrobenzene exposure — MetHgb >1% above baseline suggests significant nitrobenzene absorption.
What is nitrobenzene?
Also known as: Nitrobenzol, Benzene, nitro-, Essence of mirbane, nitro-Benzene.
- IUPAC name
- nitrobenzene
- CAS number
- 98-95-3
- Molecular formula
- C6H5NO2
- Molecular weight
- 123.11 g/mol
- SMILES
- C1=CC=C(C=C1)[N+](=O)[O-]
- PubChem CID
- 7416
Risk for people
Moderate riskTransdermal absorption of nitrobenzene is highly significant — OSHA's skin notation acknowledges that dermal contact is a major route of methemoglobin-inducing exposure, potentially exceeding inhalation in occupational settings where skin contact is uncontrolled. Dermal absorption kinetics: nitrobenzene is a lipophilic liquid (log P = 1.85) that penetrates intact skin readily; dermal absorption rate estimated at 0.3–2 mg/cm²/hr from liquid contact — a worker with hand/forearm immersion in liquid nitrobenzene could absorb a methemoglobin-inducing dose within minutes of unprotected contact. Historical occupational poisoning: mass methemoglobinemia poisoning from nitrobenzene dermal absorption has been documented in munitions workers (nitrobenzene used as intermediates in explosive synthesis) and aniline dye factory workers; exposures through contaminated clothing represent a sustained absorption source that continues after leaving the workplace. 'Oil of mirbane' soap exposure: nitrobenzene was widely used in inexpensive 'almond-scented' soaps and shoe polishes in the 19th and early 20th centuries — handwashing and shoe-polishing created regular dermal contact; pediatric and adult methemoglobinemia from these products is documented in historical toxicology literature. PPE: butyl rubber gloves provide the best protection against nitrobenzene dermal absorption; nitrile and neoprene offer moderate protection; decontamination with soap and water for any skin contact is essential. Monitoring: urinary p-nitrophenol (primary metabolite) and blood MetHgb % are the key biological exposure indices for nitrobenzene exposure — MetHgb >1% above baseline suggests significant nitrobenzene absorption.
Regulatory consensus
8 regulatory and scientific bodies have classified Nitrobenzene. The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| OSHA | — | Occupational exposure limit | |
| EPA CTX / IRIS | — | Likely to be carcinogenic to humans | |
| EPA CTX / NTP RoC | — | Reasonably Anticipated to be a Human Carcinogen | |
| EPA CTX / IARC | — | Group 2B - Possibly carcinogenic to humans | |
| EPA CTX / EPA OPP | — | Group D Not Classifiable as to Human Carcinogenicity | |
| EPA CTX / CalEPA | — | Known human carcinogen | |
| EPA CTX / Genetox | — | Genotoxicity: negative (Ames: negative, 0 positive / 7 negative reports) | |
| EPA CTX / Genetox | — | Genotoxicity: negative (Ames: negative, 0 positive / 7 negative reports) |
Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.
Where you encounter nitrobenzene
- Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
- Occupational Environments — Factories, Warehouses, Transportation vehicles
-
Fragrance
— perfume, cologne, scented personal care products, household fragrance products, candles
Identified in Fragrance Ingredient Safety Priority Research database (2,325 ingredients)
Safer alternatives
Lower-risk approaches that achieve a similar outcome to Nitrobenzene:
-
Fragrance-free formulations
Trade-offs: Consumer preference for scented productsRelative cost: Lower (ingredient elimination)
-
Essential oil-based fragrances (with disclosure)
Trade-offs: Natural does not mean safe — many essential oils are skin sensitizersRelative cost: 2-5× conventional
Frequently asked questions
Is nitrobenzene safe for you?
Transdermal absorption of nitrobenzene is highly significant — OSHA's skin notation acknowledges that dermal contact is a major route of methemoglobin-inducing exposure, potentially exceeding inhalation in occupational settings where skin contact is uncontrolled. Dermal absorption kinetics: nitrobenzene is a lipophilic liquid (log P = 1.85) that penetrates intact skin readily; dermal absorption rate estimated at 0.3–2 mg/cm²/hr from liquid contact — a worker with hand/forearm immersion in liquid nitrobenzene could absorb a methemoglobin-inducing dose within minutes of unprotected contact. Historical occupational poisoning: mass methemoglobinemia poisoning from nitrobenzene dermal absorption has been documented in munitions workers (nitrobenzene used as intermediates in explosive synthesis) and aniline dye factory workers; exposures through contaminated clothing represent a sustained absorption source that continues after leaving the workplace. 'Oil of mirbane' soap exposure: nitrobenzene was widely used in inexpensive 'almond-scented' soaps and shoe polishes in the 19th and early 20th centuries — handwashing and shoe-polishing created regular dermal contact; pediatric and adult methemoglobinemia from these products is documented in historical toxicology literature. PPE: butyl rubber gloves provide the best protection against nitrobenzene dermal absorption; nitrile and neoprene offer moderate protection; decontamination with soap and water for any skin contact is essential. Monitoring: urinary p-nitrophenol (primary metabolite) and blood MetHgb % are the key biological exposure indices for nitrobenzene exposure — MetHgb >1% above baseline suggests significant nitrobenzene absorption.
What products contain nitrobenzene?
Nitrobenzene appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments); perfume (Fragrance).
Why do regulators disagree about nitrobenzene?
Nitrobenzene has been classified by 8 agencies including OSHA, EPA CTX / IRIS, EPA CTX / NTP RoC, EPA CTX / IARC, EPA CTX / EPA OPP, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.
See Nitrobenzene in the body app
Look up products containing nitrobenzene, compare to alternatives, and explore the full data record.
Open in body View raw API dataSources (2)
- NIOSH Pocket Guide: Nitrobenzene — PEL 1 ppm (skin); IDLH 200 ppm; methemoglobin formation; methylene blue antidote; aniline feedstock; dermal absorption; urinary p-nitrophenol biomarker (2019) (2019) — regulatory
- NTP Report on Carcinogens: Nitrobenzene — reasonably anticipated human carcinogen; thyroid/liver tumors rodents; HAP Clean Air Act; oil of mirbane historical use; industrial methemoglobinemia outbreaks (2021) (2021) — regulatory
Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →