Section 410-4 (c) permits fixtures to be installed in commercial cooking hoods where all of the following conditions are met.
1. The fixture must be identified for use within commercial cooking hoods and installed so that the temperature limits of the materials used are not exceeded.
2. The fixture must be constructed so that all exhaust vapors, grease, oil or cooking vapors are excluded from the lamp and wiring compartment. Diffusers shall be resistant to thermal shock.
3. Parts of the fixture exposed within the hood must be corrosion resistant or protected against corrosion, and the surface shall be smooth so as not to collect deposits and facilitate cleaning.
4. Wiring methods and materials supplying the fixture(s) must not be exposed within the cooking hood. This mess fails because item No. 4 is violated.