1(2H)-Phthalazinone

1-(2h)-phthalazinone appears as pale yellow crystals. Insoluble in water. (NTP, 1992)

Pale yellow solid; [CAMEO] Beige crystalline solid; [Aldrich MSDS]

Warning

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

P264, P270, P301+P317, P330, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 44 reports by companies from 2 notifications to the ECHA C&L Inventory.

Status: Active Update: 07-12-2017 https://echa.europa.eu/registration-dossier/-/registered-dossier/21566

1(2H)-Phthalazinone: Does not have an individual approval but may be used under an appropriate group standard

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.

SMALL SPILLS AND LEAKAGE: Should a spill occur while you are handling this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with ethanol and transfer the dampened material to a suitable container. Use absorbent paper dampened with ethanol to pick up any remaining material. Seal the absorbent paper, and any of your clothes, which may be contaminated, in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)

1(2H)-Phthalazinone (PA) was tested for mutagenicity in the Salmonella/microsome preincubation assay using a protocol approved by the National Toxicology Program. PA was tested over a wide range of doses (0, 100, 333, 1000, 3333, and 10,000 ug/plate) in four Salmonella typhimurium strains (TA98, TA100, TA1535, and TA1537) in the presence and absence of Aroclor-induced rat or hamster liver S9. PA was negative in these tests and the highest ineffective dose level tested in any Salmonella tester strain was 10,000 ug/plate.

Phthalazinone

Pesticide degradation product

Smith, C.D. and Nowell, L.H., 2024. Health-Based Screening Levels for evaluating water-quality data (3rd ed.). DOI:10.5066/F71C1TWP

Used as a chemical intermediate for hydralazine (antihypertensive agent); [HSDB]

CHEM INT FOR HYDRALAZINE, AN ANTIHYPERTENSIVE AGENT

(1977) No Data

(1979) No Data

(1976) 6.47X10+6 GRAMS (PRINCPL CUSTMS DISTS)

(1979) 6.01X10+5 GRAMS (PRINCPL CUSTMS DISTS)

(1977) 1.30X10+8 GRAMS

(1979) PROBABLY GREATER THAN 2.27X10+6 GRAMS