Reaction mass of sodium chloride and sodium iodide and sodium sulphate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

publication

Title:

Chemical Substance Search (Sodium iodide)

Author:

Registered substances-ECHA

Bibliographic source:

http://echa.europa.eu/web/guest/information-on-chemicals/registered-substances?p_p_id=48_INSTANCE_Rfk8&_48_INSTANCE_Rfk8_iframe_q=Hydroquinone&_48_INSTANCE_Rfk8_iframe_legal=true

Materials and methods

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium iodide

EC Number:

231-679-3

EC Name:

Sodium iodide

Cas Number:

7681-82-5

Molecular formula:

INa

IUPAC Name:

Sodium iodide

Details on test material:

As sodium iodide is with 56% the main compound of this reaction mass a read-across of data from this salt to cover this endpoint for the reaction mass is assumed to be acceptable.

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Test organisms

Test organisms (species):

Daphnia magna

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Details on test conditions:

Stocks of Daphnia were raised in the laboratory following a minor modification to the Ontario Ministry of the Environment protocol (Poirier et al. 1988). The Daphnia were fed a mixture of two algal species: Selenastrum capricornutum (UTCC #37) and Chlorella emersonii (UTCC #86), both of which were obtained as pure cultures from the University of Toronto Algal Culture Collection of Algae and Cyanobacteria. The algal cultures were grown in a nutrient medium under artificial lighting. Rather than using Bristol's solution as suggested by Poirier et al. (1988), we used a commercially available two-part hydroponic plant food ("Bumper crop," Rambridge Structure and Design Limited, Calgary, AB). In addition, to prevent Se-deficiency, the culture water for Daphnia was supplemented with Se to a final concentration of approximately 1.0 I~g Se/L. The culture water supply was local spring water collected from an artesian aquifer in a glacial moraine, and filtered through activated charcoal, crushed limestone, and polyester floss prior to use.
Daphnia in various stages of growth were maintained to provide healthy populations and a steady supply of neonates. One day prior to testing, all neonates were removed from the tanks to ensure that only animals that were ~<24-h old were used for testing. The 48-h static, non-aerated toxicity tests were conducted at 20°C (+2°C) in a temperature-controlled water bath and a light-controlled (16-h light, 8-h dark) environment.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.17 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

dissolved

Basis for effect:

mortality

Effect concentrations 2

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.43 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

dissolved

Basis for effect:

mortality

Effect concentrations 3

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.83 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

dissolved

Basis for effect:

mortality

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

The acute toxicity of the substance to Daphnia magna was investigated in a static test. After 48 hours of exposure a LC50 value of 0.17 mg/L was obtained.

Executive summary:

The acute toxicity (96-h LC 50 ) of aqueous stable iodine species (I – , IO  3  –  , I 2 ) to rainbow trout and  Daphnia magna  were measured at three individual concentrations of hardness, total organic carbon, and chloride. Rainbow trout were most sensitive to I 2  (LC 50 0.53 mg/L), and much less sensitive to IO  3  –  (LC 50 220 mg/L) or I –  (LC 50 860 mg/L).  Daphnia magna  were equally sensitive to I 2  (LC 50 0.16 mg/L) and I –  (LC 50 0.17 mg/L), but were less sensitive to IO  3  –  (LC 50 10.3 mg/L). The external and internal radiological dose imparted by equivalent molar quantities of radioactive  125 I,  129 I, and  131 I were calculated for both the Daphnia  and trout using the LC 50  values obtained from a standard water treatment. As expected, the dose from  125 I and  131 I would exceed the expected lethal dose rate long before a chemically toxic level is reached. In contrast, a molar concentration of  129 I likely to cause death by chemical toxicity would impart a radiological dose less than that expected to be lethal. Thus, for short-lived aquatic organisms, risks due to chemical toxicity of  129 I may exceed risks due to its radioactive emissions.