Sodium acrylate

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian germ cell study: cytogenicity / chromosome aberration

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Genetic Toxicology of Acrylic Acid.

Author:

McCarthy K. L.et al.

Year:

1992

Bibliographic source:

Food Chem. Toxic. 30: 505-515

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The study was conducted according to the method described by McCarthy K. L.et al., Food Chem. Toxic. 30: 505-515 (1992).

GLP compliance:

yes

Type of assay:

rodent dominant lethal assay

Test material

Test material information

Constituent 1

Reference substance name:

Acrylic acid

EC Number:

201-177-9

EC Name:

Acrylic acid

Cas Number:

79-10-7

Molecular formula:

C3H4O2

IUPAC Name:

acrylic acid

Specific details on test material used for the study:

- Name of test material (as cited in study report): Acrylic acid
- Physical state: clear liquid
- Analytical purity: > 99.8 % (as given in McCarthy et al.)

Test animals

Species:

mouse

Strain:

CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratory, Raleigh, NC or Portage, MI.
- Age at study initiation: 8-10 weeks old
- Weight at study initiation: Males, 27-38 g
- Housing: The animals were housed in an AAALAC-accredited facility. Male mice were housed up to five per cage in plastic autoclavable cages with filter tops. Female mice were housed up to 25 per cage in large plastic autoclavable cages with metal lids.
- Diet (ad libitum): Certified laboratory rodent chow
- Water (ad libitum): Tap water

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 ± 1
- Humidity (%): 50 ± 2
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: distilled water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
For dose level selection, male animals were randomly assigned to three groups of ten males each for each of three toxicity tests (16, 54, 162 mg/kg bw) and were dosed by oral gavage with 5 daily administrations at a rate of 10 ml/kg bw. Animals were observed after each dose administration for clinical signs of chemical effect.

Duration of treatment / exposure:

Five days

Frequency of treatment:

once per day

Post exposure period:

Immediately after the last dose administration, each male mouse was mated with 2 virgin female mice. Females were checked for vaginal plugs each morning. Each mated female was replaced with a virgin female. The mating process was repeated until the males had mated for a total of 6 days in order to evaluate the effect of treatment on fertility. The subchronic mating period was reduced to 6 days due to depletion of available virgin female mice for mating.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

16 mg/kg bw/day (actual dose received)

Doses / concentrations 2

Dose / conc.:

54 mg/kg bw/day (actual dose received)

Doses / concentrations 3

Dose / conc.:

162 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

20 males / 40 females

Control animals:

yes, concurrent vehicle

Positive control(s):

cyclophosphamide
- Route of administration: gavage
- Doses / concentrations: 20 mg/kg bw

Examinations

Tissues and cell types examined:

Uterine contents (number of live and dead implants were recorded)

Evaluation criteria:

Dominant lethality (DL) was calculated according to the following formula:

DL = 1 – [Live embryos / pregnant female treated : live embryos / pregnant female control]

Parameters which also were evaluated statistically on the basis of four day mating intervals include:

- The fertility index. This paramter measures the number of fertile matings.

- The total implantations per pregnant female. A reduction in litter size is not critical evidence of mutation; however, the parameter may provide useful information regarding the effect of the test article.

- Dead implants per pregnant female (early deaths). A statistically significant increase in this parameter is reported to be the most reliable indicator of a dominant lethal effect.

- The proportion of pregnant females with one or more dead implants and with two or more dead implants. These parameters give an indication of the severity of fetal damage.

- Dead implants total implants (early deaths). This index adjusts the dead implants per pregnant female by the total implants for that female because of the positive correlation between the two. The index is a reliable indicator of dominant lethality.

- Live implants pregnant female. This parameter reflects the combined effects of preimplantation losses and dead implants.

Statistics:

The statistical assessment of the different data obtained within the present study was based on following methods, depending on the parameters considered: t-test, Chi-square analysis, the Freeman-Tukey arcsine transformation.

Results and discussion

Test results

Key result

Sex:

male/female

Genotoxicity:

negative

Toxicity:

yes

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Any other information on results incl. tables

During or shortly after dose administration, several mice were found to exhibit swelling in the shoulder region. Upon observation, it was determined that the swellings were abscesses most likely caused by bite wounds from fighting during the time that the males were group housed. Mice were found dead during the first mating week and included 4 mice receiving water, 3 mice receiving 162 mg/kg bw, 1 mouse receiving 54 mg/kg bw, 2 mice receiving 16 mg/kg bw and 4 mice receiving 20 mg CP/kg/bw/d. These deaths did not appear to be test substance related. Many of the males that died were those with the shoulder swellings observed earlier. It ispossible that the wounds from fighting were irritated by holding the mice for the gavage procedure and the animals succumbed to infection. Necropsies were not performed. Other than the swollen shoulders, all test substance-treated mice appeared normal at about 1.5 to 2 hours after each daily administration.

 

- LD: The dominant lethal indices were calculated for the test substance treated groups. No statistical evaluation was made on this index.

Dominant Lethal Index
Interval (days)	Test substance
	16 mg/kg bw	54 mg/kg bw	162 mg/kg bw
1 – 4	0.04	0.04	0.06
5 - 8	0.06	0.09	0.07
9 – 12	0.11	0.01	0.04
13 – 16	0.04	0.04	0.05
17 – 20	0	0.11	0.05
21 – 24	0.02	0.05	0.03
25 – 28	0.03	0.11	0.03
29 – 32	0.06	0.07	0.07
33 – 36	0.23	0.02	0.06
37 – 40	0.06	0.01	0.05
41 - 46	0.07	0.07	0

- The fertility index was calculated by dividing the number of pregnant mice by the number of animals mated. No difference was found between the test substance-treated and vehicle control animals.

Fertility Index
Interval (days)	Water 10 ml/kg bw	Test substance			CP 20 mg/kg bw
		16 mg/kg bw	54 mg/kg bw	162 mg/kg bw
1 – 4	0.93 (25/27)	0.86 (25/29)	0.74 (20/27)	0.88 (30/34)	0.70 (14/20)
5 - 8	0.96 (23/24)	1.00 (29/29)	0.93 (26/28)	0.94 (30/32)	0.95 (19/20)
9 – 12	0.90 (9/10)	0.89 (16/18)	0.95 (20/21)	0.90 (28/31)	1.00 (8/8)
13 – 16	1.00 (9/9)	1.00 (18/18)	0.93 (14/15)	0.94 (15/16)	0.90 (9/10)
17 – 20	0.90 (19/21)	1.00 (19/19)	0.96 (24/25)	1.00 (18/18)	0.88 (14/16)
21 – 24	0.97 (32/33)	0.94 (31/33)	0.89 (33/37)	0.90 (28/31)	0.90 (26/29)
25 – 28	0.94 (30/32)	0.97 (30/31)	0.94 (29/31)	1.00 (29/29)	0.96 (25/26)
29 – 32	0.81 (26/32)	0.82 (32/39)	0.72 (23/32)	0.90 (28/31)	0.89 (25/28)
33 – 36	0.90 (18/20)	1.00 (26/26)	1.00 (17/17)	0.92 (22/24)	0.86 (19/22)
37 – 40	0.91 (20/22)	0.90 (19/21)	0.89 (25/28)	0.91 (20/22)	0.96 (23/24)
41 - 46	0.96 (46/48)	0.95 (40/42)	0.96 (48/50)	1.00 (55/55)	0.96 (47/49)

- Total implantations (live and dead) per pregnant female: A reduction in total implantations was observed at 54 mg/kg/bw/d at mating intervals 17-20, 25-28 and 41-46 and at 16 mg/kg/day at 9-12 days. CP significantly reduced the total implantations at days 1-4, 5-8, 9-12, 17-20 and 21-24.

Mean implantations (live and dead) per pregnant female
Interval (days)	Water 10 ml/kg bw	Test substance			CP 20 mg/kg bw
		16 mg/kg bw	54 mg/kg bw	162 mg/kg bw
1 – 4	11.64	11.72	11.90	12.07	9.79^*
5 - 8	12.78	12.00	12.81	12.27	11.26^*
9 – 12	13.11	12.06^*	13.10	12.61	11.50^*
13 – 16	12.00	12.33	12.36	12.73	11.78
17 – 20	12.74	12.26	10.96^*	12.72	10.57^*
21 – 24	12.09	11.74	12.58	11.71	11.12^*
25 – 28	12.53	12.00	11.03^*	11.72	11.92
29 – 32	12.27	12.09	11.52	11.61	11.60
33 – 36	11.72	13.85	12.12	12.36	12.26
37 – 40	12.05	11.21	11.96	11.50	11.70
41 - 46	12.00	11.28	10.96^*	11.95	11.87

CP: Cyclophosphamide

^*Significantly increased relative to vehicle control (p≤0.05)

 

 

- Mean dead implants per pregnant female: A statistically significant increase in the mean number of dead implants per pregnant female was observed at 54 mg/kg/day in the 5-8 day mating interval and at 16 mg/kg at 29-32 days. A number of female mice removed from males during the 5-8 day mating interval appeared dehydrated at the time of sacrifice. The cause of the dehydration is not known but the animals did have free access to water at all times. These mice had an increased number of dead implants which were probably due to the dehydration and not to test substance effect. The increase seen days 33-36 was probably due to the low concurrent control at this time point since the test article-substance value was not unlike those at other weeks. CP significantly increased the number of dead implants at intervals 1-4, 5-8, 9-12, 13-16, and 21-24.

Mean dead implants per pregnant female
Interval (days)	Water 10 mL/kg bw	Test substance			CP 20 mg/kg bw
		16 mg/kg bw	54 mg/kg bw	162 mg/kg bw
1 – 4	0.72	0.32	1.40	0.53	2.71^*
5 - 8	0.61	0.62	1.77^*a	0.97^a	3.58^*
9 – 12	0.44	0.75	0.50	0.50	4.25^*
13 – 16	0.44	0.28	0.36	0.60	2.11^*
17 – 20	0.79	0.26	0.33	0.17	0.86
21 – 24	0.59	0.42	0.42	0.57	1.38^*
25 – 28	0.70	0.50	0.55	0.28	0.84
29 – 32	0.27	0.78^*	0.39	0.43	0.56
33 – 36	0.78	0.35	0.94	0.73	1.42
37 – 40	0.70	0.53	0.52	0.70	0.48
41 - 46	0.52	0.60	0.31	0.49	0.38

CP: Cyclophosphamide

^*Significantly increased relative to vehicle control (p≤0.05)

^aSome pregnant females were dehydrated at sacrifice

 

- Mean live implants per pregnant female: The live implants were significantlyreduced at 16 mg/kg/bw/day during mating interval 9-12 and at 54 mg/kg/bw/day during mating interval 25-28. CP markedly reduced the number of live implants at mating intervals 1-4, 5-8, 17-20 and 21-24.

 

- The proportion of pregnant females with one or more dead implants was increased at 16 mg/kg/day at days 29-32. The proportion of pregnant females with two or more dead implants was not increased in the test substance-treated groups. CP significantly increased the proportion of pregnant females with one or more dead implants at days 1-4, 5-8, 9-12, and 21-24 and with two or more dead implants at days 1-4, 5-8, and 9-12.

 

- The mean number of dead implants per total implants was observed to be significantly increased at days 5-8 at 54 mg/kg/bw/day and at days 29-32 at 16 mg/kg/bw/day. The increase observed at days 5-8 is probably due to dehydration described above. The increase seen days 33-36 was probably do to the low concurrent control at this time point since the test substance-treated value was not unlike those at other weeks. CP significantly increased the dead implants per total implants at mating intervals 1-4, 5-8, 9-12, 13-16, and 21-24.