Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Toxicological information

Genetic toxicity: in vivo

Currently viewing:

Administrative data

Endpoint:
in vivo mammalian cell study: DNA damage and/or repair
Type of information:
experimental study
Adequacy of study:
key study
Study period:
08 February 2022 - ongoing
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2022

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 489 (In vivo Mammalian Alkaline Comet Assay)
Version / remarks:
2016
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of assay:
unscheduled DNA synthesis

Test material

Constituent 1
Chemical structure
Reference substance name:
Zinc bis(benzenesulphinate)
EC Number:
246-148-1
EC Name:
Zinc bis(benzenesulphinate)
Cas Number:
24308-84-7
Molecular formula:
C12H10O4S2Zn
IUPAC Name:
zinc bis(benzenesulphinate)
Specific details on test material used for the study:
Test Article: ZBS
Alternate Identification: Benzenesulfinic acid zinc salt
CAS Number: 24308-84-7
Lot/Batch Number: 20211015
Description: White powder
Expiration Date: 14 October 2022

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male
Details on test animals or test system and environmental conditions:
Species: Rat, Rattus norvegicus
Strain: Sprague Dawley® (Harlan;SD)
Source: Envigo Laboratories (Frederick, MD, USA)
Number/Sex: 30 males
Acclimation: At least 7 days
Age at Administration: 7 – 8 weeks of age
Weight at Administration: 251.0 – 279.5 grams

Housing: 2–3 per cage
Cage Changes: Twice per week
Diet: ad libitum
Water: ad libitum
Temperature: 20 – 25°C
Humidity: 30 – 70%
Lighting: 12-/12-hour light/dark cycle

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
Deionized Water
Details on exposure:
For 2 consecutive days, the animals were administered 1 of 4 dose levels of ZBS, the vehicle, or the positive control EMS via oral gavage.
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day
Remarks:
Vehicle control
Dose / conc.:
250 mg/kg bw/day
Remarks:
zinc bis(benzenesulphinate)
Dose / conc.:
500 mg/kg bw/day
Remarks:
zinc bis(benzenesulphinate)
Dose / conc.:
1 000 mg/kg bw/day
Remarks:
zinc bis(benzenesulphinate)
Dose / conc.:
2 000 mg/kg bw/day
Remarks:
zinc bis(benzenesulphinate)
Dose / conc.:
150 mg/kg bw/day
Remarks:
EMS
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Positive control(s):
Ethyl Methanesulfonate (EMS)
CAS: 62-50-0

Examinations

Tissues and cell types examined:
Liver, blood, and kidney tissues
Details of tissue and slide preparation:
Blood was collected for analysis of peripheral lymphocytes. A blood volume of 50 μl was transferred to a microcentrifuge tube containing 1 ml of mincing solution (Mg++ and Ca++ free Hanks Balanced Salt Solution, 10% v/v DMSO, and 20 mM EDTA, pH 7.4–7.7) and mixed. Duplicate samples were prepared.
Following exsanguination, portions of the liver and kidneys were collected for analysis. The left lobe of the liver was cut longitudinally into 2 sections. Two small sections were further cut from 1 section and kept cold and moist with mincing solution for comet analysis. Each small section of liver tissue was placed in a separate microcentrifuge tube containing 1 mL of mincing solution and rapidly minced to generate duplicate samples. The second section of the left lobe will be fixed in 10% NBF, trimmed, and paraffin-embedded for potential histopathology evaluation. The remaining portions of liver tissue were discarded.
A transverse section of the right kidney was collected, from which 2 small sections were cut, and kept cold and moist with mincing solution for comet analysis. Each small section of kidney tissue was placed in a separate microcentrifuge tube containing 1 mL of mincing solution and rapidly minced to generate duplicate samples. Both kidneys were fixed in 10% NBF, trimmed, and paraffin-embedded for possible histopathology evaluation. The carcass and remaining tissues were discarded.
All tubes containing tissue samples for the comet assay were flash frozen in liquid nitrogen and stored in a -80℃ freezer until processed.

Frozen tissue samples (1 of the duplicate tubes per animal) were removed from the freezer, thawed appropriately, and kept cold during processing. A portion of the cell suspension of each tissue sample was empirically diluted with 0.5% NuSieve™ GTG™ low melting point agarose (Lonza, Durham, NC, USA) dissolved in phosphate buffer (Ca2+, Mg2+ and phenol red-free) at 37 ± 2℃ and layered onto at least 2 commercially available CometSlides™ or Flare™ slides (Trevigen, Gaithersburg, MD, USA). The cell suspension volume did not decrease the percentage of low melting point agarose by more than 10% (i.e., not below 0.45%). The slides were immersed overnight in chilled lysing solution (2.5 M NaCl, 100 mM Na2EDTA, 10 mM Tris, pH 10, with 10% dimethyl sulfoxide, and 1% Triton X-100 added fresh) in a refrigerator under light-proof conditions.
After this incubation period, the slides were rinsed in purified water or neutralization solution (0.4 M Trizma base at pH 7.5) to remove residual detergent and salts prior to the alkali unwinding step. Slides were randomly placed onto the platform of a submarine-type electrophoresis unit and cold electrophoresis solution (300 mM NaOH, 1 mM Na2EDTA; pH > 13) added. The slides were left to unwind at ≤ 10℃ for 20–25 minutes, then electrophoresed at ≤10℃ for 20 minutes at 25 V (0.7–1.0 V/cm), with a current of approximately 300 mA. After electrophoresis, slides were neutralized with 0.4 M Trizma base (pH 7.5) for ≥ 5 minutes and then dehydrated by immersion in absolute ethanol (≥ 99.6%) for ≥ 5 minutes and allowed to air dry. Air-dried slides were stored in a desiccator at room temperature with ≤ 60% relative humidity until stained and scored. Stained slides were stored desiccated.

Results and discussion

Test results
Sex:
male
Remarks on result:
other: Study ongoing

Any other information on results incl. tables

























































Dose Level (mg/kg/day)



Number of Animals


(N)



% Tail DNA



Blood



Kidney



Liver ˄



0



4



0.50 ± 0.23



2.55 ± 0.36



1.36 ± 0.96



250



5



1.09 ± 0.24



1.86 ± 0.71



1.79 ± 0.46



500



5



0.92 ± 0.76



3.14 ± 1.59



2.60 ± 0.72*



1000



5



0.71 ± 0.20



2.06 ± 1.11



1.89 ± 0.53



2000



5



0.83 ± 0.78



2.60 ± 0.85



2.55 ± 1.15*



EMS 150a



5



11.37 ± 1.75*



12.53 ± 2.06*



12.32 ± 2.50*



Abbreviations: EMS = ethyl methanesulfonate


Values are group means ± standard deviation


* p ≤ 0.05. Dunnett’s test and linear trend test, except where indicated


˄ Increasing linear trend


a t-test

Applicant's summary and conclusion