¶ MIBK (Methyl isobutyl ketone)
This ketone is a colourless liquid with a sweet odor that is used as a solvent for gums, resins, paints, varnishes, etc. but is also used as a developer for PMMA-based e-beam resists. It is a highly flammable liquid and vapor, and may cause drowsiness or dizziness and in pure for is possibly carcinogenic (group 2B, as suspected by the IARC).
¶ Diluted form: AR 600-56
Although pure MIBK is a health hazard, the MIBK we regularly use in the cleanroom is diluted with IPA) (ratio MIBK / IPA is 1:3), which, according to the MSDS does not have the health hazard.