US EPA

1763085 

Journal Article 

Biodegradability and microbial toxicity of aircraft fuel system icing inhibitors 

Meshako, CE; Bleckmann, CA; Goltz, MN 

1999 

Yes 

Environmental Toxicology
ISSN: 1520-4081
EISSN: 1522-7278 

14 

4 

383-390 

English 

10.1002/(SICI)1522-7278(1999)14:4<383::AID-TOX2>3.0.CO;2-M 

WOS:000082154600002 

In a pollution prevention and chemical substitution effort, the U.S. Air Force and Navy formed a joint initiative to find safer, more environmentally acceptable jet fuel system icing inhibitors (FSII) for military aircraft. Standard biochemical oxygen demand (BOD) analysis and variations of the BOD procedure were used as simple screening tools to evaluate the potential for aquatic biodegradation and microbial toxicity of proposed FSIIs. This laboratory evaluation of biological properties allows prediction of the biotreatability of the chemicals in wastewater treatment plants, and their potential application as biocides at higher concentrations. The current FSII, diethylene glycol monomethyl ether (DiEGME) was evaluated along with two new candidate compounds, dipropylene glycol and glycerol formal. At a low concentration (3.5 mg/L), DiEGME exerted a BOD5 of about 27% of theoretical oxygen demand. Test concentrations of ≥7 mg/L had decreasing oxygen consumption rate and extent, typical of a material with potential aquatic microbial toxicity. Dipropylene glycol began to moderately degrade only after more than 3 weeks exposure to microorganisms obtained from raw sewage. Glycerol formal showed no signs of biodegradation during a 5‐week test period. In a simple microbial toxicity test DiEGME was most toxic, dipropylene glycol was moderately toxic, and glycerol formal showed little toxicity. At low concentrations (7 mg/L), none of the chemicals significantly inhibited microbial activity (P=0.34).