Metam-sodium

Endpoint summary

Description of key information

Short term toxicity fish:

The aim of this study was to ascertain whetherMetam-sodium was developmentally toxic to embryos zebrafish during gastrulation and early segmentation periods and also detect the effects on the mortality, hatching pattern and notochord defect. A sodium metam stock solution of 0.29 M (37.46 mg/l) was prepared in water at pH 9 was stored at 4° C until further dilution. Adult AB strain zebrafish (Danio rerio) were raised and kept at standard laboratory conditions of 28° C on a 14 h light/10 h dark photoperiod. Fish water consisted of reverse osmosis water supplemented with a commercially available salt solution (0.6% Instant Ocean). 20 embryos were added in 20 ml of glass vials sealed with Teflon-lined lids to prevent loss by volatilization. After the exposure period, effect were observed and test performed in three replicates. Based on the effect on the mortality the LC50 was determine at 0.25 mg/l. But defect in Notochord and hatching pattern of embryos zebrafish, the EC50 was determine at 0.038 mg/l and 0.036 mg/l by the chemical exposureMetam-sodium for 48 hrs. As the effect were observed at the very low concentration thus chemical was consider as toxic and can be consider to be classified as aquatic acute category 1 as well as chronic 1 as per the CLP classification criteria.

Short term toxicity to aquatic invertebrates:

Aim of this study was to determine the effect of chemical Metam-sodium on the growth of aquatic cladoceran crustacean Daphnia magna by utilizing Toxkits (culture/maintenance-free microbiotests). Test conducted according to the OECD and ISO test protocols for the acute Daphnia magna toxicity tests for 24 hrs of total exposure period. Toxicant dilution series of the blind water samples was prepared with the test chemical. Neonate daphnids that were younger than 24 h were used. Hatching of the ephippia was initiated 3–4 days prior to the start of the toxicity tests by incubating the dormant eggs in petri dishes with ISO medium at 20 °C under a constant illumination of 6000 lux. Multiwell test plates were used in the study. In the plate rinsing wells present contain 5 daphnia per well with 5 ml of test solution. The wells of each row were checked and the number of dead or immobilized neonates was recorded versus that of the actively swimming test organisms in each well. Based on the immobility of daphnia magna due to the exposure of chemical Metam-sodium for 24 hrs of exposure, the EC50 was determine to be 0.61 mg/l. thus chemical was consider as toxic and can be consider to be classified as aquatic acute category 1 as well as chronic 1 as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria:

Study was conducted to assess the effect of chemical on growth and survival of Euglena gracilis Z in the absence of light (dark) as well as in presence of light. Test conducted at 0, 0.1, 1, 5 and 10 mg/l concentration. The organism was grown in the Euglena medium, pH 5.5 under constant illumination from fluorescent lamps with constant agitation at 22°C. The intensity of illumination was 200 ft-C at the surface of the flasks. Cells were harvested and washed with fresh medium by centrifugation and used as an inoculum for experiments. Celt numbers were determined after the indicated times with a Coulter Counter Model B. Based on the growth rate inhibition and effect on the survival of Euglena gracilis (Flagellate Euglenoid), the inhibitory concentration was determine to be 1 mg/l in the absence and presence of light. Based on the effect observed chemical was consider as toxic as the 88 % toxicity were observed at the 1 mg/l so on that basis chemical was consider as toxic and classified as aquatic acute 1 as well as chronic 1 category as per the CLP classification criteria.

Toxicity to microorganisms:

Pseudomonas cell proliferation inhibition test by the chemical metam-sodium for 18 hrs was carried out. After the 18 hrs exposure of chemical with the test organism, the EC10 was observed at 0.6 mg/l. Thus chemical was consider as toxic to the growth of microorganism Pseudomonas putida.

Additional information

Summarized result for the determination of nature of chemical Metam-sodium (137-42-8) on the growth and other biological and physical activity of fish, aquatic invertebrates, algae and cyanobacteria and microorganisms when chemical comes in contact with test organisms, by considering the data for target chemical from various sources which are as follows:  

 

Short term toxicity fish:

Based on the various experimental data for the target chemical Metam-sodium (137-42-8) study have been reviewed to determine toxic nature of on the growth and other activity of fish. The studies are as mentioned below: 

 

In the first key experimental study for the Metam-sodium (137-42-8) from peer reviewed journal (toxicological sciences 2004), study was to ascertain whether Metam-sodium was developmentally toxic to embryos zebrafish during gastrulation and early segmentation periods and also detect the effects on the mortality, hatching pattern and notochord defect. A sodium metam stock solution of 0.29 M (37.46 mg/l) was prepared in water at pH 9 was stored at 4° C until further dilution. Adult AB strain zebrafish (Danio rerio) were raised and kept at standard laboratory conditions of 28° C on a 14 h light/10 h dark photoperiod. Fish water consisted of reverse osmosis water supplemented with a commercially available salt solution (0.6% Instant Ocean). 20 embryos were added in 20 ml of glass vials sealed with Teflon-lined lids to prevent loss by volatilization. After the exposure period, effect were observed and test performed in three replicates. Based on the effect on the mortality the LC50 was determine at 0.25 mg/l. But defect in Notochord and hatching pattern of embryos zebrafish, the EC50 was determine at 0.038 mg/l and 0.036 mg/l by the chemical exposure Metam-sodium for 48 hrs. As the effect were observed at the very low concentration thus chemical was consider as toxic and can be consider to be classified as aquatic acute category 1 as well as chronic 1 as per the CLP classification criteria.

 

 

Similarly in the second experimental study from the same source for Metam-sodium (137-42-8), toxicity was measured. Study was to ascertain whether Metam-sodium was developmentally toxic to embryos zebrafish and show any effect on the hatching pattern and mortality. A sodium metam stock solution of 0.29 M (37.46 mg/l) was prepared in water at pH 9 was stored at 4° C until further dilution. Adult AB strain zebrafish (Danio rerio) were raised and kept at standard laboratory conditions of 28° C on a 14 h light /10 h dark photoperiod. Fish water consisted of reverse osmosis water supplemented with a commercially available salt solution (0.6% Instant Ocean). 20 embryos were added in 20 ml of glass vials sealed with Teflon-lined lids to prevent loss by volatilization. After the exposure period, effect were observed. Based on the effect on the hatching pattern and mortality of embryos zebrafish, the LOEL (Lowest-observable-effect-level) was determine at 0.02 mg/l by the chemical exposure Metam-sodium. As the effect were observed at the very low concentration thus chemical was consider as toxic and can be consider to be classified as aquatic acute category 1 as well as chronic 1 as per the CLP classification criteria.

 

Above studies was supported by another handbooks and authoritative database for the Metam-sodium (137-42-8) from (HSDB, IUCLID dataset, Pesticides properties and AGROTOX, 2018). Aim of this study was to determine the nature of chemical Metam-sodium on the growth of aquatic fishes Lepomis macrochirus. Study was conducted under the static system for 96 hrs of exposure. After exposure abnormal swimming behaviour, apathy was observed. Based on the mortality of test organisms by the chemical Metam-sodium for 96 hrs, the LC50 was observed at 0.175 mg/l and NOEC was determine at 0.215 mg/l. Thus based on the LC50, chemical was consider as toxic and classified as aquatic acute 1 as well as chronic 1 category as per the CLP classification criteria.

 

Similarly in the fourth supporting study for the chemical the Metam-sodium (137-42-8) from authoritative database 2018 supports the classification of chemical. Aim of this study was to determine the nature of chemical Metam-sodium on the growth of aquatic fishes. Study was conducted under the static system for 96 hrs of exposure. Based on the mortality of test organisms by the chemical Metam-sodium for 96 hrs, the LC50 was observed at 35 mg/l. Thus based on the LC50, chemical was consider as toxic and classified as aquatic chronic 3 category as per the CLP classification criteria.

 

As the above studies conducted on different fishes and condition and exposure time was also different, thus toxicity was observed in the range of 0.175 to 35 mg/l. But as the experimental full studies conducted according to the standard conditions thus on that basis, chemical was consider as toxic and can be consider to be classified as aquatic acute category 1 as well as chronic 1 as per the CLP classification criteria.

 

Short term toxicity to aquatic invertebrates:

Based on the various experimental data for the target chemical Metam-sodium (137-42-8) study have been reviewed to determine toxic nature of on the growth and other activity of invertebrates. The studies are as mentioned below: 

In the first key experimental study for the Metam-sodium (137-42-8) from peer reviewed journal (Journal of applied toxicology, 2004). Aim of this study was to determine the effect of chemical Metam-sodium on the growth of aquatic cladoceran crustacean Daphnia magna by utilizing Toxkits (culture/maintenance-free microbiotests). Test conducted according to the OECD and ISO test protocols for the acute Daphnia magna toxicity tests for 24 hrs of total exposure period. Toxicant dilution series of the blind water samples was prepared with the test chemical. Neonate daphnids that were younger than 24 h were used. Hatching of the ephippia was initiated 3–4 days prior to the start of the toxicity tests by incubating the dormant eggs in petri dishes with ISO medium at 20 °C under a constant illumination of 6000 lux. Multiwell test plates were used in the study. In the plate rinsing wells present contain 5 daphnia per well with 5 ml of test solution. The wells of each row were checked and the number of dead or immobilized neonates was recorded versus that of the actively swimming test organisms in each well. Based on the immobility of daphnia magna due to the exposure of chemical Metam-sodium for 24 hrs of exposure, the EC50 was determine to be 0.61 mg/l. thus chemical was consider as toxic and can be consider to be classified as aquatic acute category 1 as well as chronic 1 as per the CLP classification criteria.

 

Similarly in the second experimental study for Metam-sodium (137-42-8) from (Journal of Economic Entomology 1967), toxicity was measured. Aim of this study was to determine the nature of chemical Metam-sodium on the growth of aquatic invertebrate daphnia magna by providing the total exposure of 26 hrs. Standard solution was prepared in acetone and exactly I ml of each of these standard solutions was placed in 1 liter of Standard Test Medium in a 2-liter Erlenmeyer flask and mixed thoroughly. 100 ml of this mixture were placed in each of the ten 4-oz bottles. Thus each rack contained 10 bottles of the chemical to be tested at a concentration of 1.0, 0.1, 0.01 or 0.001/ppm. A rack containing 10 bottles of water to which 1 ml of acetone was added was always included in every test run, to serve as a control. 10 daphnia <24 h Larvae (1ST INSTAR) were added in 4-oz round glass bottles. Test repeated 10 times for exact effect determination. After the exposure of chemical, lethal dose at which 50 % mortality observed were recorded. Based on the mortality of test organism daphnia magna by the chemical Metam-sodium for the period of 26 hrs, the LD50 was observed at 0.33 mg/l. Thus based on the effect chemical was consider as toxic and can be consider to be classified as aquatic acute 1 as well as chronic 1 category as per the CLP classification criteria.

 

Above studies was supported by another handbooks and authoritative database for the Metam-sodium (137-42-8). Aim of this study was to determine the toxic effect of chemical Metam-sodium on the growth of Cypridopsis vidua (Ostracod, Seed Shrimp). Test were conducted in the static system for total exposure period of 48 hrs. Mature Cypridopsis vidua used in the study. After the incubation period of 48 hrs lethal concentration at which 50 % mortality was observed were recorded. Based on the mortality of Cypridopsis vidua (Ostracod, Seed Shrimp) by the chemical Metam-sodium for 48 hrs, the LC50 was determine at 0.035 mg/l. thus based on the LC50, chemical was consider as toxic and can be consider to be classified as aquatic acute 1 as well as chronic 1 category as per the CLP classification criteria.

 

Similarly the fourth study from secondary source ECOTOX 2018, was conducted to determine the effect of chemical Metam sodium (137-42-8) on the growth of aquatic invertebrate daphnia magna for 48 hrs. Test conducted under the static system in which > 24 hrs old daphnia magna exposed with the chemical and effect were determine by observing the immobility. Based on the immobility of daphnia magna because of the chemical Metam sodium exposure for 48 hrs, the EC50 was determine to be 2.36 mg/l. Thus chemical was consider as toxic and can be consider to be classified as aquatic chronic category 2 as per the CLP classification criteria.

 

In the fifth supporting study for the target chemical Metam sodium (137-42-8) from secondary source ECOTOX 2018 observed that the chemical was toxic to the invertebrates. Aim of this study was to determine the toxic effect of chemical Metam-sodium on the growth of Penaeus aztecus. Test conducted under the flow-through system for 48 hrs of duration. Salter water 35-75 MM Juvenile Penaeus aztecus was used as a test organism. During the time of exposure effect on the mobility (on 50 % test organisms) were observed. Based on the immobility of Penaeus aztecus due to the chemical Metam-sodium for 48 hrs of exposure the EC50 was determine at 10 mg/l. Thus chemical was consider as toxic and classified as aquatic chronic 3 as per the CLP classification criteria.

 

Similarly sixth study from Pesticide Properties Database (PPDB) 2017 for target chemical also supports the classification of target chemical. Aim of this study was to determine the effect of chemical Metam-sodium on the growth of aquatic invertebrate daphnia magna. Test conducted for 48 hrs and the effect were measured at which chemical effect on 50 % daphnia magna. Based on the immobility of daphnia magna by the chemical Metam-sodium for 48 hrs of exposure, the EC50 was determine at 0.99 mg/l. Thus chemical was consider as toxic and classified as aquatic acute 1 as well as chronic 1 as per the CLP classification criteria.

 

According to another supporting study for Metam-sodium (137-42-8) from Plant Protection Phentopharmaceuticals Database, 2012 chemical was toxic. Aim of this study was to determine the effect of chemical Metam-sodium on the growth of aquatic invertebrate daphnia magna. Test conducted for 48 hrs for observing the toxic effect of chemical. Based on the immobility of daphnia magna by the chemical metam-sodium, the EC50 was determine at 2.34 mg/l. Based on the EC50. Chemical was consider as toxic and classified as aquatic chronic 2 as per the CLP classification criteria.

 

 

As the above studies conducted on different invertebrates, environmental conditions and exposure time was also different, thus toxicity was observed in the range of 0.035 to 10 mg/l. But as the experimental full studies conducted according to the standard conditions and maximum studies supports the toxicity nature of chemical thus on that basis, chemical was consider as toxic to aquatic invertebrates and can be consider to be classified as aquatic acute category 1 as well as chronic 1 as per the CLP classification criteria.

 

Toxicity to aquatic algae and cyanobacteria:

Based on the various experimental data and predicted data for the target chemical Metam-sodium (137-42-8) study have been reviewed to determine toxic nature of on the growth and other activity of invertebrates. The studies are as mentioned below: 

 

In the first key experimental study for the Metam-sodium (137-42-8) from peer reviewed journal (Bulletin of Environmental Contamination & Toxicology 1970), study was conducted to assess the effect of chemical on growth and survival of Euglena gracilis Z in the absence of light (dark) as well as in presence of light. Test conducted at 0, 0.1, 1, 5 and 10 mg/l concentration. The organism was grown in the Euglena medium, pH 5.5 under constant illumination from fluorescent lamps with constant agitation at 22°C. The intensity of illumination was 200 ft-C at the surface of the flasks. Cells were harvested and washed with fresh medium by centrifugation and used as an inoculum for experiments. Celt numbers were determined after the indicated times with a Coulter Counter Model B. Based on the growth rate inhibition and effect on the survival of Euglena gracilis (Flagellate Euglenoid), the inhibitory concentration was determine to be 1 mg/l in the absence and presence of light. Based on the effect observed chemical was consider as toxic as the 88 % toxicity were observed at the 1 mg/l so on that basis chemical was consider as toxic and classified as aquatic acute 1 as well as chronic 1 category as per the CLP classification criteria.

 

Similarly in the second experimental study for Metam-sodium (137-42-8) from secondary source Draft Assessment Report 2007 toxicity was measured on the growth of algae. Determination of the level of concentration at which it affects the growth of algae Pseudokirchneriella subcapitata (green alga). Test conducted according to the OECD Guideline 201: Alga, Growth Inhibition Test. Chemical was an analytically monetarized by HPLC with spectrophotometric detector. 96 hours study was performed under the static system on 1 x 104 cells/mL. 3 replicates for per concentration and 6 replicates for per control was used. Effect were measured after 72 hrs and 96 hrs. Based on the biomass rate inhibition of Pseudokirchneriella subcapitata by the chemical the EC50 was determine in range of 0.704 mg/l to 0.715 mg/l. On the basis of growth rate inhibition after 72 hrs EC50 was determined at 1.30 mg/l and after 96 hrs inhibition observed at 1.36 mg/l. Based on the EC50 (0.704 mg/l to 0.715 mg/l) test chemical was consider as toxic and concluded to be classified in aquatic acute 1 as well as chronic 1 category as per the CLP classification criteria.

 

Above studies was supported by another handbooks and authoritative database (Pesticide Properties Database) for the Metam-sodium (137-42-8). Study was conducted to assess the effect of chemical Metam-sodium on growth and survival of Pseudokirchneriella Subcapitata. After the chemical exposure for 72 hrs effect were observed on the growth of algae. Based on the growth rate inhibition of Pseudokirchneriella subcapitata due to the chemical Metam-sodium, the EC50 was determine to be 1.08 mg/l. based on the EC50 chemical was consider as toxic and can be consider to be classified as aquatic acute 1 as well as chronic 1 as per the CLP classification criteria.

 

Similarly in the fourth supporting data prediction done using the EPI Suite ECOSAR version 1.10, the short term toxicity on green algae was predicted for test substance Metam-sodium. On the basis of effects observed in a static freshwater system, the effect concentration EC50 value for the substance is estimated to be 0.55 mg/l for green algae for 96 hrs duration. Based on this value, it can be concluded that the test chemical Metam-sodium can be considered as toxic to green algae at environmentally relevant concentrations and can be considered to be classified in aquatic acute 1 / chronic category 1 as per the CLP classification criteria.

 

Based on the effect observed on the growth of aquatic algae and cyanobacteria, by the chemical Metam-sodium (137-42-8) from various experimental reports, it was conclude that the chemical was toxic and consider to be classified as aquatic acute 1 as well as chronic 1 category as per the CLP classification criteria.

 

Toxicity to microorganisms:

 

Based on the various experimental data for the target chemical Metam-sodium (137-42-8) study have been reviewed to determine toxic nature of on the growth and other activity of invertebrates. The studies are as mentioned below: 

 

In the first study for the target chemical Metam-sodium (137-42-8) from (IUCLID dataset 2000) toxicity was measure on the growth of microorganisms. Pseudomonas cell proliferation inhibition test by the chemical metam-sodium for 18 hrs was carried out. After the 18 hrs exposure of chemical with the test organism, the EC10 was observed at 0.6 mg/l. Thus chemical was consider as toxic to the growth of microorganism Pseudomonas putida.

 

Similarly in the second study for the target chemical Metam-sodium (137-42-8) from (IUCLID dataset 2000) determine the nature of chemical on the microorganisms. Aim of this study was to determine the toxic effect of chemical on the Short-term breathing of activated sludge (aquatic bacteria). After the exposure of chemical metam-sodium with the test organism activated sludge, the EC20 was observed at > 1995 mg/l. Thus chemical was consider as nontoxic to the growth of microorganism Pseudomonas putida. 

Thus based on the overall studies on the growth of fish, aquatic invertebrates and algae, it can be concluded that the chemical was toxic and can be consider to be classified as aquatic acute 1 as well as chronic 1 category as per the CLP classification criteria.