2-nitrotoluene

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms, other

Type of information:

other: EU Risk Assessment

Adequacy of study:

other information

Reliability:

other: EU Risk Assessment

Rationale for reliability incl. deficiencies:

other: No reliability is given as this is a summary entry for the EU RAR.

Principles of method if other than guideline:

EU Risk Assessment

GLP compliance:

not specified

Specific details on test material used for the study:

- Analytical purity: not specified

Executive summary:

EU Risk Assessment (2008):

Yoshioka et al., (1986) carried out the "activated sludge, respiration inhibition test" proposed by the OECD providing an EC50 of 665 mg/l on inhibiting the respiration of activated sludge, after a three-hour exposure period. The activated sludge was obtained from a treatment plant, treating predominantly domestic sewage.

Deneer et al.(1989) indicated a log EC50 of 1.13 µmol/l (EC50 of 1.8 mg/l) for the bioluminescence of Photobacterium phosphoreum. Tests with P. phosphoreum, and calculations causing 50% reduction of bioluminiscence after 15 min of exposure were carried out as described in the Beckman Instruments Manual (1982). This test was considered not assignable for the assessment evaluation.

In the same way, Zhao and Wang (1995) provided information on P. phosphoreum. Ecotoxicological descriptors were the EC50 inhibition of bioluminiscence after 15 minutes exposure at 20 ºC, according to the procedures described in the Instrument Manual. It results in an EC50 of 16.9 mg/l. This assay is considered not assignable for the assessment purpose.

Bringmann and Kuehn (1977) tested 2-nitrotoluene on Pseudomonas putida. Exposure time was 16h at 25 ºC. Growth rate was determined measuring the final turbidity that was measured and compared to controls, using a Hg-lamp wavelength of 436 nm. Measure chamber 10 mm thickness. The toxicity threshold concentration (EC3) on P. putida was determined as 18 mg/l.

There are two data included in the IUCLID database by Hoechst (1984). The authors carried out a growth inhibition test on industrial activated sludge, using the ETAD fermentation tube method. For an exposure period of 24 hours it is indicated a NOEC of 60 mg/l and an EC50 of 80 mg/l. These values are included as additional information but it will not be accounted for the assessment estimations since no validation of the original report was possible.

There is also some information, which are presented below, regarding the effects on unicellular protozoa.

In another study, Yoshioka et al.(1985) measured an EC50 of 100 mg/l for the growth inhibiting effect of 2-nitrotoluene on the protozoa Tetrahymena pyriformis, after an exposure period of 24 hours.

Bringmann and Kuehn (1981) gave the following Toxic Threshold Concentrations (EC5) measuring the cell growth inhibition rate of various protozoa. Quantitative estimation of initial cell number and cell growth is achieved through a culture counter. The following EC5s are presented: 46 mg/l on Entosiphon sulcatum (bacteriovorous flagellate protozoa, consuming flagellate) after 72h exposure; 24 mg/l on Uronema parduczi holozoic (bacteriovorous ciliate protozoa, consuming ciliate) after 20h exposure and 27 mg/l on Chilomonas paramecium (saprozoic flagellate protozoa) after 48h exposure.

Reference 2

Endpoint:

toxicity to microorganisms, other

Type of information:

other: BUA report

Adequacy of study:

other information

Reliability:

other: BUA report

Rationale for reliability incl. deficiencies:

other: No reliability is given as this is a summary entry for the BUA report.

Principles of method if other than guideline:

BUA report

GLP compliance:

not specified

Specific details on test material used for the study:

unpublished internal study report

Executive summary:

BUA report (1989):

In a growth inhibition test with Pseudomonas putida, the following toxic threshold concentrations were found for o-nitrotoluene:

TTC (= EC3) = 18 mg/l after 16 hrs (Bringmann and Kuehn, 1977).

Other studies on the effect of o-nitrotoluene on Pseudomonas fluorescens and the intestinal bacterium Escherichia coli gave the following figures (18-h cell growth inhibition test), with damaging effects indicated only at higher concentrations. No damaging effect was found up to 500 mg/l for Pseudomonas fluorescens and Escherichia coli (Bayer AG, 1986).

Among the measurements made in a study on the effect of aromatic nitro compounds on the bioluminescence of Photobacterium phosphoreum was the mononitrotoluene concentration which causes a 50% reduction in the bacterium's glowing intensity, compared to that of the control, after exposure for 15 minutes. The EC50value for o-nitrotoluene was 1.85 mg/l (Deneer et al., 1988).

In an O2-consumption test according to the OECD for activated sludge an EC50 of 665 mg/l was obtained after a 3-h test period (Yoshioka et al., 1986).

A cell growth inhibition test with various protozoa gave the following results (Bringmann and Kuehn, 1981):

Entosiphon sulcatum - holoz. bact. consuming flagellate:

TTC (= EC5) = 46 mg/l after 72 h

Uronema pardiczi - holoz. bact. consuming ciliate:

TTC (= EC5) = 24 mg/l after 20 h

Chilomonas paramaecium - sapr. flagellate:

TCC (=EC5) = 27 mg/l after 48 h

An EC50of 100 mg/l was recorded for the cell growth inhibition effect of o-nitrotoluene on Tetrahymena pyriformis after a test duration of 24 h (Yoshioka et al., 1985).

Description of key information

For transported isolated intermediates according to REACh, Article 18, this endpoint is not a data requirement. However, data is available for this endpoint and is thus reported under the guidance of "all available data".

EU Risk Assessment (2008):

Yoshioka et al., (1986) carried out the "activated sludge, respiration inhibition test" proposed by the OECD providing an EC50 of 665 mg/l on inhibiting the respiration of activated sludge, after a three-hour exposure period. The activated sludge was obtained from a treatment plant, treating predominantly domestic sewage.

Deneer et al.(1989) indicated a log EC50 of 1.13 µmol/l (EC50 of 1.8 mg/l) for the bioluminescence of Photobacterium phosphoreum. Tests with P. phosphoreum, and calculations causing 50% reduction of bioluminiscence after 15 min of exposure were carried out as described in the Beckman Instruments Manual (1982). This test was considered not assignable for the assessment evaluation.

In the same way, Zhao and Wang (1995) provided information on P. phosphoreum. Ecotoxicological descriptors were the EC50 inhibition of bioluminiscence after 15 minutes exposure at 20 ºC, according to the procedures described in the Instrument Manual. It results in an EC50 of 16.9 mg/l. This assay is considered not assignable for the assessment purpose.

Bringmann and Kuehn (1977) tested 2-nitrotoluene on Pseudomonas putida. Exposure time was 16h at 25 ºC. Growth rate was determined measuring the final turbidity that was measured and compared to controls, using a Hg-lamp wavelength of 436 nm. Measure chamber 10 mm thickness. The toxicity threshold concentration (EC3) on P. putida was determined as 18 mg/l.

There are two data included in the IUCLID database by Hoechst (1984). The authors carried out a growth inhibition test on industrial activated sludge, using the ETAD fermentation tube method. For an exposure period of 24 hours it is indicated a NOEC of 60 mg/l and an EC50 of 80 mg/l. These values are included as additional information but it will not be accounted for the assessment estimations since no validation of the original report was possible.

There is also some information, which are presented below, regarding the effects on unicellular protozoa.

In another study, Yoshioka et al.(1985) measured an EC50 of 100 mg/l for the growth inhibiting effect of 2-nitrotoluene on the protozoa Tetrahymena pyriformis, after an exposure period of 24 hours.

Bringmann and Kuehn (1981) gave the following Toxic Threshold Concentrations (EC5) measuring the cell growth inhibition rate of various protozoa. Quantitative estimation of initial cell number and cell growth is achieved through a culture counter. The following EC5s are presented: 46 mg/l on Entosiphon sulcatum (bacteriovorous flagellate protozoa, consuming flagellate) after 72h exposure; 24 mg/l on Uronema parduczi holozoic (bacteriovorous ciliate protozoa, consuming ciliate) after 20h exposure and 27 mg/l on Chilomonas paramecium (saprozoic flagellate protozoa) after 48h exposure.

BUA report (1989):

In a growth inhibition test with Pseudomonas putida, the following toxic threshold concentrations were found for o-nitrotoluene:

TTC (= EC3) = 18 mg/l after 16 hrs (Bringmann and Kuehn, 1977).

Other studies on the effect of o-nitrotoluene on Pseudomonas fluorescens and the intestinal bacterium Escherichia coli gave the following figures (18-h cell growth inhibition test), with damaging effects indicated only at higher concentrations. No damaging effect was found up to 500 mg/l for Pseudomonas fluorescens and Escherichia coli (Bayer AG, 1986).

Among the measurements made in a study on the effect of aromatic nitro compounds on the bioluminescence of Photobacterium phosphoreum was the mononitrotoluene concentration which causes a 50% reduction in the bacterium's glowing intensity, compared to that of the control, after exposure for 15 minutes. The EC50value for o-nitrotoluene was 1.85 mg/l (Deneer et al., 1988).

In an O2-consumption test according to the OECD for activated sludge an EC50 of 665 mg/l was obtained after a 3-h test period (Yoshioka et al., 1986).

A cell growth inhibition test with various protozoa gave the following results (Bringmann and Kuehn, 1981):

Entosiphon sulcatum - holoz. bact. consuming flagellate:

TTC (= EC5) = 46 mg/l after 72 h

Uronema pardiczi - holoz. bact. consuming ciliate:

TTC (= EC5) = 24 mg/l after 20 h

Chilomonas paramaecium - sapr. flagellate:

TCC (=EC5) = 27 mg/l after 48 h

An EC50of 100 mg/l was recorded for the cell growth inhibition effect of o-nitrotoluene on Tetrahymena pyriformis after a test duration of 24 h (Yoshioka et al., 1985).