The "Nitration of benzaldehyde to 3-nitrobenzaldehyde" is an experiment of medium difficulty. The selectivity is only average because of the formation of byproducts. For the same reason also the yield is relatively low .

The mass efficiency is a little lower than average compared to other NOP experiments .

The reaction product 3-nitrobenzaldehyde as well as the byproducts produced in lower yield as 2-nitrobenzaldehyde and 4-nitrobenzaldehyde have not been adequately tested for toxicology and ecotoxicology. The educt benzaldehyde does not possess significant acute or chronic toxicity.
According to theoretical prediction methods both the product 3-nitrobenzaldehyde and all byproducts are suspected to have mutagenic, carcinogenic and sensitizing properties. Also - according to theoretical prediction methods - these substances are probably not easily degradable and may have a substantial toxicity for aquatic organisms.
The organic solvents used in this experiment show only low acute toxicity and no chronic effects. The inorganic educt and reagents fuming nitric acid and the concentrated sulfuric acid are very hazardous because of their very corrosive properties, but this danger can easily be averted by appropriate safety measures. During the nitration reaction very toxic nitrogen oxide gases may be produced. All other inorganic auxiliary substances do not pose any hazard to human health .

The product, the byproducts and the solvents petroleum ether (60-80) and tert-butyl methyl ether are biologically not easily degradable, and some are classified as dangerous to the environment because of their toxicity to aquatic organisms .

Summed up this experiment has a low economic efficiency (in the laboratory) and medium toxicological risks as well as a relatively high environmental persistence of the products. In comparison with other nitration reactions in the NOP experiments it still has the most favorable risk assessment, thus we evaluate it with the "yellow light".