Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 626-470-2
CAS number: 5405-40-3
- Table 1: Concentrations of DL-LACTONE in test medium (final
Relative tonominal [%]
(1) Mean of duplicate analysis. The maximum deviation between the
responses was calculated for each sample and was < 10%.
(2) Without algea.
n.d.: not detected.
n.a.: not applicable.
In the chromatograms recorded for the nominal 100 mg/L samples
taken at t=24 hours and t=72 hours, an extra peak was observed at a
retention time smaller than the retention time of RS-Pantolactone. The
extra peak increased in time. The presence of an extra peak in the
chromatograms indicated that the decrease of the test item was probably
related to degradation. Based on the measured concentrations the algal
suspensions had been exposed to an average measured concentration of 78
- Table 2: Extinction values measured during the range-finding
Hours of exposure
24 48 72
Based on these results the EC50 was expected to be above 100 mg/I and
the project was continued with a final limit study.
- Table 3: Mean cell densities during the limit test
Concentration(mg/L)DL-LACTONENominal / Actual *
Exposure time (hours)
100 / 78
* Average measured concentration.
- Table 4: Percentage inhibition of cell growth and reduction of
growth rate during the limit test.
Concentration (mg/L)DL-LACTONENominal / Actual *
Cell growth (0-72 hrs)
Mean growth rate p: (cells/mL/h)
Mean area (A)
µ (0-72 hrs)
- Table 5: pH levels recorded during the limit study.
Nominal / Actual *
Total cell growth:
Mean Area for 0-72h
Inhibition in %
Reduction in %
RS-Pantolactone (named DL-LACTONE in the report) was tested for it's
toxicity to aquatic algae and cyanobacteria with Selenastrum
capricormutum in the Fresh Water Algal Growth Inhibition Test. The study
procedures described in this report were based on the EEC Directive
92/69, Publication No. L383 Part C-3 adopted December, 1992; OECD
guideline No. 201, Adopted June 7, 1984; and ISO Standard 8692, First
edition, 15 November 1989.
The test item was completely soluble at the concentrations tested. After
a range-finding test, a limit test was performed exposing exponentially
growing algal cultures to a RS-Pantolactone concentration of 100 mg/L
and to a blank-control. The initial cell density was 10^4 cells/mL. The
total test period was 72 hours. Samples for analysis of actual exposure
concentrations were taken at the start, after 24 hours of exposure and
at the end of the test period. Sampling included a test solution
prepared at 100 mg/L incubated without algal cells present.
Analysis of the samples showed that the concentrations measured at the
start of the test were in agreement with nominal. Further, the measured
concentration remained above 80 % relative to the initial concentration
during the first 24-hour exposure period. At the end of the 72-hour
exposure period, the concentration measured in the sample taken from the
solution with algae had decreased to 45 mg/L, whereas the concentration
measured in the solution without algae remained at 76 mg/L. The presence
of an extra peak in the chromatograms indicated that this decrease was
probably related to degradation.
RS-Pantolactone induced no effect on algal growth at a concentration of
100 mg/L during 72 hours of incubation. The exposure included
degradation of the test item, which was at least partly related with
The EC50 for both algal growth and growth rate exceeded a concentration
of 100 mg/L (NOEC), corresponding with an average measured concentration
of 78 mg/L.
By expert judgement it is concluded that L-Pantolactone will get the
L-Pantolactone: Algea, 72h EC50: 100 mg/L
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again