Lysine hydrochloride

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 20/02/2008 - 27/03/2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was performed according to the OECD guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

not specified

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: "IV Growth Inhibition test with Algae" (modified Nov 20,2006) in the Annex to "On Test Methods of New Chemical Substances" (Nov 21,2003, Yakushoku No.1121002, Heisei 15-11-13, Seikyoku No.2, Kanhoki No. 031121002)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Lysine hydrochloride

EC Number:

211-519-9

EC Name:

Lysine hydrochloride

Cas Number:

657-27-2

Molecular formula:

C6H14N2O2.ClH

IUPAC Name:

lysine hydrochloride

Constituent 2

Reference substance name:

L-lysine hydrochloride

EC Number:

233-234-9

EC Name:

L-lysine hydrochloride

Cas Number:

10098-89-2

IUPAC Name:

L-lysine hydrochloride

Details on test material:

- Name of test material (as cited in study report): L-lysine hydrochloride
- Analytical purity: 100.1%
- Lot/batch No.: 070039
- Expiration date of the lot/batch: April 25, 2008
- Stability under test conditions: Stability was confirmed by comparing the IR spectrum at the begining and end of the test
- Storage condition of test material: Dark and cool place

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 100 mg/L
- Sampling method: For the determination of the test substance concentration in the test solution, samples were taken at 0; 24; 48 and 72 h from the mid layer of each vessel. The algal bodies were removed by centrifugation (1750xg, 10 min) and the aqueos phase analysed by HPLC. For counting of algal cells, 2 mL of the test solutions from each test vessel was mixed with 18 mL (or 19 mL) of electrolyte solution (ISOTON II) followed by determination using a particle counter.
- Sample storage conditions before analysis: not mentioned

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 100 mg/L was prepared by weighing 0.0799 g of the test substance (0.0800 g as active ingredient) with an electronic balance, washing it with medium into a vessel which had been partially filled with medium, and further diluting it with remaining amount of the medium to make a final volume of 800 mL.
- Eluate: OECD recommended medium
- Controls: included; non-treated controls

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Monocellular green algae
- Source (laboratory, culture collection): ATCC2262

Study design

Test type:

other: open system (with a breathable silicone stopper) and shake cultures (100 rpm)

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

not mentioned

Test conditions

Hardness:

not mentioned

Test temperature:

20.7-21.2C

pH:

pH at test initiation= 7.6-7.9
pH at test completion=8.3

Dissolved oxygen:

not mentioned

Salinity:

not mentioned

Nominal and measured concentrations:

Nominal concentration: 100 mg/L
Measured concentrations:
101 mg/L at t=0h
99.4 mg/L at t=24h
102 mg/L at t=48h
99.6 mg/L at t=72h

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass Erlenmeyer falsk of 300 mL
- Type (delete if not applicable): open system (with a breathable silicone stopper) and shake culture (100 rpm)
- Initial cells density: 10000 cells/mL
- Control end cells density: 1324000 cell/mL
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6


GROWTH MEDIUM
- Standard medium used: yes


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: not mentioned
- Photoperiod: continuous
- Light intensity and quality: fluorescent lamp of 400-700 nm; photon flux density 60-120 µE/m2/s ± 15% (near surface of the solution)


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
EC50 (0-72h) and NOEC (0-72h)

TEST CONCENTRATIONS
- Results used to determine the conditions for the definitive study: In the limit test, no significant differences were detected in the growth rates (0-72 h) of either 10 mg/L or 100 mg/L when compared to that on the non-treated control. Therefore, the definitive test was conducted at 100 mg/L.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

other: NOECr

Effect conc.:

100 mg/L

Basis for effect:

growth rate

Results with reference substance (positive control):

- Results with reference substance valid?
- ErC50 (0-72h): 0.92 mg/L. Sensitivity confirmation tests had been conducted every 6 month
- Other: Background data (February 2007 - October 2007) were 1.2 - 1.5 mg/L (n = 2 ).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The ErC50 of L-lysine hydrochloride to Pseudokirchneriella subcapitata was > 100 mg/L and NOECr was 100 mg/L, based on mean measured concentrations.

Executive summary:

The acute toxicity of L-lysine hydrochloride to Pseudokirchneriella subcapitata (6 replicates/concentration, intial biomass 1 x 10⁴cells/mL) was assessed according to OECD 201. The nominal test concentration was 100 mg/L. Measured concentrations of the test substance in the test solutions during the exposure period were well maintained, i.e. within range of 99 - 102 % of the nominal value. Average measured concentration during the exposure period was 100 mg /L. The ErC50 (0 -72h) was >100 mg/L and NOECr (0 -72h) was 100 mg/L.