Formic acid, manufacture of, by-products from

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

It is considered appropriate to address the data requirements for reaction mass of 2,2-bis(formyloxymethyl)propane-1,3-diyl diformate and formic acid by read-across to the available studies on structurally similar substances.
Reaction mass of 2,2-bis(formyloxymethyl)propane-1,3-diyl diformate and formic acid is comprised of formic acid (free) up to 59%, propylidynetrimethanol (trimethylolpropane, TMP) up to 35%, and pentaerythritol up to 19.6%.
Aquatic microorganism toxicity studies are available on formic acid, propylidynetrimethanol (trimethylolpropane, TMP), and pentaerythritol. The data requirements for reaction mass of 2,2-bis(formyloxymethyl)propane-1,3-diyl diformate and formic acid are addressed by read-across to formic acid, propylidynetrimethanol (TMP) and pentaerythritol.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Specific details on test material used for the study:

Formic acid, propylidynetrimethanol (trimethylolpropane, TMP), and pentaerythritol are being used as a read across for 2,2-bis(formyloxymethyl)propane-1,3-diyl diformate and formic acid.

Key result

Duration:

13 d

Dose descriptor:

NOEC

Effect conc.:

72 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: Key data from formic acid study

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: Key data from TMP study

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: Key data from TMP study

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: Key data from pentaerythritol study

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: Key data from pentaerythritol study

Details on results:

The key data from aquatic microorganism toxicity studies on formic acid, propylidynetrimethanol (trimethylolpropane, TMP), and pentaerythritol are used for weight of evidence read across to reaction mass of 2,2-bis(formyloxymethyl)propane-1,3-diyl diformate and formic acid.

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of the target substance, reaction mass of 2,2-bis(formyloxymethyl)propane-1,3-diyl diformate and formic acid, to aquatic microorganisms was estimated to be 13 d NOEC = 72 mg/L and 3 h EC50 = >1000 mg/L, based on worst case read-across studies on activated sludge (from domestic and predominately domestic sewage, respectively).

Executive summary:

Studies on microorganism toxicity are available for the read-across substances formic acid, propylidynetrimethanol (trimethylolpropane, TMP) and pentaerythritol:

The inhibition control of a ready biodegradability study of formic acid was used for the assessment of toxicity to microorganisms. No inhibition of degradation activity was shown at a test substance concentration of 72 mg/L, and was therefore considered to be the NOEC.

The respiration inhibition of activated sludge from predominantly domestic sewage treatment plant by TMP was determined according to the EU Guideline C.11 with an incubation time of 3 hours. The EC50 and the EC10 for TMP were determined to be > 1000 mg/L.

The toxicity of pentaerythritol to activated sewage sludge was investigated in a respiration inhibition test according to OECD test guideline 209. Following 3 hours exposure to pentaerythritol the EC50 was observed to be > 1000 mg/L (based on nominal exposure concentrations), the corresponding NOEC was observed to 1000 mg/L.

Description of key information

The lowest available EC50 for the read-across substances was found to be 1000 mg/l.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

EC10 or NOEC for microorganisms:

72 mg/L

Additional information

Studies on microorganism toxicity are available for the read-across substances formic acid, propylidynetrimethanol (trimethylolpropane, TMP) and pentaerythritol:

For formic acid the inhibition control of a test on ready biodegradability was used for the assessment of toxicity to microorganisms. As at a test substance concentration of 72 mg/L no inhibition of degradation activity occured, so this is considered to be the NOEC.

The respiration inhibition of activated sludge from predominantly domestic sewage treatment plant by TMP was determined according to the EU Guideline C.11 with an incubation time of 3 hours. The concentrations tested were 10, 100 and 1000 mg/L. EC50 of the reference substance 3,5 - dichlorophenole was 9.2 mg/L ( 95% C.I. 3 - 24 mg/L). The respiration rates of the 2 controls differed less than 15% from each other.

The EC50 and the EC10 for TMP were determined to be > 1000 mg/L.

The toxicity of pentaerythritol to activated sewage sludge was investigated in a respiration inhibition test according to OECD test guideline 209. Following three hours exposure to pentaerythritol the EC50 was observed to be > 1000 mg/L (based on nominal exposure concentrations), the corresponding NOEC was observed to 1000 mg/L.