CAS 104-91-6PubChem CID 7729
4-Nitrosophenol
P-benzoquinone monoxime is a black solid. (NTP, 1992) — CAMEO Chemicals
- IUPAC name
- 4-nitrosophenol
- Molecular formula
- C6H5NO2
- Molecular weight
- 123.11 g/mol
- Exact mass
- 123.032028402 Da
- XLogP3
- 1.3
- Topological polar surface area
- 49.7 Ų
- Hydrogen-bond donors
- 1
- Hydrogen-bond acceptors
- 3
- Covalent units
- 1
- Defined stereocentres
- 0
Also known as
p-NitrosophenolPhenol, 4-nitroso-Quinone monoximeNitrosophenolQuinone oximePhenol, p-nitroso-1,4-Benzoquinone monoximepara-Nitrosophenol
16 more reported names
55EB58H2UPNSC-3124RefChem:526027203-251-64-Benzoquinone Monoxime637-62-7p-Quinone monoximeQuinone monooxime1,4-Benzoquinone 4-oximep-Quinone monooxime4-NitrosofenolQuinone 4-oximep-Benzoquinone 4-oximep-Benzoquinone, monooximep-Chinonmonoximp-Benzoquinone monoxime
External database identifiers
- ChEMBL:CHEMBL104353
- ChEMBL:CHEMBL3276923
- EPA DTXSID:DTXSID0025991
- EPA DTXSID:DTXSID0075287
- PubMed:22565268
- PubMed:21467676
- PubMed:21430963
- PubMed:20668897
- PubMed:19522482
- PubMed:17616175
- PubMed:12727284
- PubMed:12699383
- PubMed:12598009
- PubMed:11952336
- PubMed:11695611
Evidence from additional scientific databases
NIH PubChem PUG-View
Exact identifier match7729
Attributed physical-property, hazard, environmental and use annotations.
- Color/Form: PALE YELLOW ORTHORHOMBIC NEEDLES, BROWNS @ 126 °C Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: CRYSTALLIZES IN LIGHT BROWN LEAFLETS Source: Hazardous Substances Data Bank (HSDB)
- Dissociation Constants: KA= 3.3X10-7 @ 25 °C Source: Hazardous Substances Data Bank (HSDB)
- Melting Point: 270 to 291 °F (decomposes) (NTP, 1992) Source: CAMEO Chemicals
- Physical Description: P-benzoquinone monoxime is a black solid. (NTP, 1992) Source: CAMEO Chemicals
- Physical Description: Wet Solid Source: EPA Chemical Data Reporting (CDR)
- Physical Description: Pale yellow or light-brown solid; [HSDB] Black solid; [CAMEO] Yellow-brown powder; [MSDSonline] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Solubility: less than 1 mg/mL at 70 °F (NTP, 1992) Source: CAMEO Chemicals
- Solubility: MODERATELY SOL IN WATER; SOL IN DILUTE ALKALIES GIVING GREEN TO BROWNISH GREEN SOLUTIONS; SOL IN ALC, ETHER, ACETONE Source: Hazardous Substances Data Bank (HSDB)
- Solubility: SOL IN HOT BENZENE Source: Hazardous Substances Data Bank (HSDB)
- Vapor Pressure: 0.15 [mmHg] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- First Aid: EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.; SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.; INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) shou Source: CAMEO Chemicals
- Signal: Danger Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
- GHS Hazard Statements: H302: Harmful if swallowed [Warning Acute toxicity, oral]; H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]; H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H411: Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard] Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
- Precautionary Statement Codes: P203, P264, P264+P265, P270, P273, P280, P301+P317, P305+P354+P338, P317, P318, P330, P391, P405, and P501 (click each P-code to see the statement) Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
- Signal: Danger Source: European Chemicals Agency (ECHA)
- GHS Hazard Statements: H242 (20.7%): Heating may cause a fire [Danger Self-reactive substances and mixtures; Organic peroxides]; H301 (11.7%): Toxic if swallowed [Danger Acute toxicity, oral]; H302 (88.3%): Harmful if swallowed [Warning Acute toxicity, oral]; H315 (56.4%): Causes skin irritation [Warning Skin corrosion/irritation]; H317 (55.9%): May cause an allergic skin reaction [Warning Sensitization, Skin]; H318 (100%): Causes serious eye damage [Danger Serious eye damage/eye irritation]; H341 (100%): Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H411 (88.3%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]; H413 (11.7%): May cause long lasting harmful effects to aquatic life [Hazardous to the aquatic environment, long-term hazard] Source: European Chemicals Agency (ECHA)
- Precautionary Statement Codes: P203, P210, P234, P235, P240, P261, P264, P264+P265, P270, P272, P273, P280, P301+P316, P301+P317, P302+P352, P305+P354+P338, P317, P318, P321, P330, P332+P317, P333+P317, P362+P364, P370+P378, P391, P403, P405, P410, P411, P420, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
- ECHA C&L Notifications Summary: Aggregated GHS information provided per 188 reports by companies from 8 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website. Source: European Chemicals Agency (ECHA)
- Signal: Danger Source: Hazardous Chemical Information System (HCIS), Safe Work Australia
- GHS Hazard Statements: H302: Harmful if swallowed [Warning Acute toxicity, oral]; H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]; H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H411: Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard] Source: Hazardous Chemical Information System (HCIS), Safe Work Australia
- Precautionary Statement Codes: P203, P264, P264+P265, P270, P273, P280, P301+P317, P305+P354+P338, P317, P318, P330, P391, P405, and P501 (click each P-code to see the statement) Source: Hazardous Chemical Information System (HCIS), Safe Work Australia
- Industry Uses: Intermediate Source: EPA Chemical Data Reporting (CDR)
- Sources/Uses: Used as a chemical intermediate for dyes; metal complexes for camouflage dyes, and hydroquinone; [HSDB] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Uses: MFR OF DYES Source: Hazardous Substances Data Bank (HSDB)
- Uses: CHEM INT FOR DYES Source: Hazardous Substances Data Bank (HSDB)
- Uses: CHEM INT FOR METAL COMPLEX USED AS DYE FOR CAMOUFLAGES Source: Hazardous Substances Data Bank (HSDB)
- Uses: CHEM INT, EG, FOR HYDROQUINONE Source: Hazardous Substances Data Bank (HSDB)
Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record
Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.
Additional source coverage and match status
| Source | Result | Checked |
|---|---|---|
| EMBL-EBI ChEBI | No exact record | 2026-08-31 |
| NIH PubChem PUG-View | Exact match | 2026-08-31 |
A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.
Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.