Formaldehyde, oligomeric reaction products with phenol

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

The objective of the study was to determine toxicity of test chemical to aquatic alge for 24 h.

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

no

Details on test solutions:

Details on test solutions
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: standard sock solution were prepared in distilled water according to the standard method. Appropriate dilutions of industrial wastewater were then prepared using water from the source of the receiving stream.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

- Common name: green algae
- Method of cultivation: Scenedesmus quadricauda was cultured in the nutrient solution prepared according to Holm Hansen
- Age of inoculum : ten days old

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test temperature:

20 ± 1 °C

pH:

7.8

Details on test conditions:

OTHER TEST CONDITIONS
- Photoperiod: continuous illumination
- Light intensity and quality: A fluorescent lamp (40 W, 4500 K) and Sylvania (40 W) lamp

Reference substance (positive control):

yes

Remarks:

Phenol and formaldehyde

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

27 other: v/v%

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: oxygen production and consumption rates

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

57.5 other: v/v%

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: oxygen production and consumption rates

Details on results:

Study was conducted to determine median effective concentration of test chemical. Based on the oxygen production and consumption rates of alage Scenedesmus quadricauda by the test chemical exposure for 24 hrs, the EC10 and EC50 was determine to be 27.0 and 57.5 v/v%, respectively.

Reported statistics and error estimates:

Effective concentrations (EC10, EC50) for algae were calculated using linear regression analysis (APHA-AWWA-WEF)

Table: Toxicity of phenol and formaldehyde to Scenedesmus quadricauda

Scenedesmus quadricauda	Phenol (mg/L)	Formaldehyde (mg/L)
24h EC10	184	3.6
24h EC50	403	14.7
24h EC90	882	60.3

Validity criteria fulfilled:

not specified

Conclusions:

Study was conducted to determine median effective concentration of test chemical. Based on the oxygen production and consumption rates of alage Scenedesmus quadricauda by the test chemical exposure for 24 hrs, the EC10 and EC50 was determine to be 27.0 and 57.5 v/v%, respectively.

Executive summary:

Short term toxicity of test chemical present in industrial wastewater was determine on the growth rate of aquatic algae. Toxicity to algae was evaluated by measuring the oxygen production and consumption rates following exposure to the test chemical. Standard sock solution were prepared in distilled water according to the standard method. Appropriate dilutions of industrial wastewater were then prepared using water from the source of the receiving stream. The pH and dissolved oxygen were measured daily. The oxygen production and consumption rates were measured on Warburg apparatus and the effective concentrations (EC10, EC50) for algae were calculated using linear regression analysis. Study also involves the finding out whether the effect of pure phenol and formaldehyde to aquatic organisms was similar to that produced by the mixture of both in the wastewater. Test was performed on ten days old Scenedesmus quadricauda for 24 hours of exposure period. The test organism was cultured in the nutrient solution prepared according to Holm Hansen under continuous illumination (3000 lx). Continuous illumination was provided by a fluorescent lamp (40 W, 4500 K) and Sylvania (40 W) lamp. Based on the oxygen production and consumption rates of algae Scenedesmus quadricauda by the test chemical exposure for 24 hrs, the EC10 and EC50  was determine to be 27.0 and 57.5 v/v%, respectively. On the basis of EC50 value and as chemical is readily biodegradable in water, we can concluded that test chemical was consider to be nontoxic and not classified as per the CLP classification criteria.

Description of key information

Study was conducted to determine median effective concentration of test chemical. Based on the oxygen production and consumption rates of alage Scenedesmus quadricauda by the test chemical exposure for 24 hrs, the EC10 and EC50  was determine to be 27.0 and 57.5 v/v%, respectively.

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

Additional information

Following different studies includes experimental study for the target chemical to observe the toxicity of test chemical to aquatic algae.

In first study, short term toxicity of test chemical present in industrial wastewater was determine on the growth rate of aquatic algae. Toxicity to algae was evaluated by measuring the oxygen production and consumption rates following exposure to the test chemical. Standard sock solution were prepared in distilled water according to the standard method. Appropriate dilutions of industrial wastewater were then prepared using water from the source of the receiving stream. The pH and dissolved oxygen were measured daily. The oxygen production and consumption rates were measured on Warburg apparatus and the effective concentrations (EC10, EC50) for algae were calculated using linear regression analysis. Study also involves the finding out whether the effect of pure phenol and formaldehyde to aquatic organisms was similar to that produced by the mixture of both in the wastewater. Chemical was analytically monitored. Test was performed on ten days old Scenedesmus quadricauda for 24 hours of exposure period. The test organism was cultured in the nutrient solution prepared according to Holm Hansen under continuous illumination (3000 lx). Continuous illumination was provided by a fluorescent lamp (40 W, 4500 K) and Sylvania (40 W) lamp. Based on the oxygen production and consumption rates of algae Scenedesmus quadricauda by the test chemical exposure for 24 hrs, the EC10 and EC50  was determine to be 27.0 and 57.5 v/v%, respectively. On the basis of EC50 value and as chemical is readily biodegradable in water, we can concluded that test chemical was consider to be nontoxic and not classified as per the CLP classification criteria.

The aim of the second study was to determine the effect of test chemical present in industrial wastewater on the aquatic green algae by providing the exposure period of 24 hrs. Toxicity to algae was evaluated by measuring the oxygen production and consumption rates following exposure to the test chemical. The untreated wastewater samples from a chemical industry producing test chemical were taken at the site of wastewater discharge into the river. The 24 h flow proportional wastewater samples were collected and transported to the laboratory in coolers with icepacks. The samples were stored in the dark at 4°C for analyses performed within three days, or frozen at –18°C until use. All wastewater samples were used for testing without any pre-treatment. The test organisms were exposed to different concentrations of test chemicals. Based on the oxygen production and consumption rates of algae Scenedesmus quadricauda by the test chemical exposure for 24 hrs, the median effect concentration (EC50) of test material was determined to be 57.7 v/v% . On the basis of EC50 value and as chemical is readily biodegradable in water, we can concluded that test chemical was consider to be nontoxic and not classified as per the CLP classification criteria.

On the basis of above determined EC50 values and as chemical is readily biodegradable in water, we can concluded that test chemical was consider to be nontoxic and not classified as per the CLP classification criteria.