Xylose

Endpoint summary

Description of key information

oral: Japan MHLW Guideline; LD50 > 2200 mg/kg bw (male rat) ; LD50 > 2500 mg/kg (female rat); reliability = 2

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: MHLW (Ministry of Health, Labor and Welfare of Japan), 1996: Guidelines for Designation of Food Additives, and for Revision of Standard for Use of Food Additives, Article No. 29 of the Life and Sanitation Bureau.

Deviations:

no

GLP compliance:

not specified

Test type:

other: oral feeding

Limit test:

no

Species:

rat

Strain:

Fischer 344/DuCrj

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Japan Inc.
- Age at study initiation: 6-week-old
- Fasting period before study: no
- Housing: plastic cages with woodchip bedding (three or four male rats/cage, five female rats/cage)
- Diet (e.g. ad libitum): basal diet (CRF-1) ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 ± 1°C
- Humidity (%): 55 ± 5%
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12-h light/dark cycle

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

DIET PREPARATION: Diets were prepared once every three months by the forage supplier and preserved in the dark at 4°C prior to use.

Doses:

Nominal: 2.5% and 5% in diet
Actual Ingested (Male): 1033 mg/kg/day and 2214 mg/kg/day
Actual Ingested (Female) 1203 mg/kg/day and 2513 mg/kg/day

No. of animals per sex per dose:

50/sex/dose

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 104 weeks
- Frequency of observations and weighing: All rats were observed daily for clinical signs and deaths. Body weights were measured once a week for the first five weeks of the study and then once every five weeks.
- Necropsy of survivors performed: yes
- Other examinations performed: organ weights, histopathology, haematology

Statistics:

Data for body weights were analyzed by the Students t-test. Haematology, organ weight and final body weight data were analyzed for homogeneity of variance using the Bartletts test. Where the samples proved to be homogeneous, one-way analysis of variance was employed. If significant heterogeneity of variance (P < 0.01) was apparent, the equivalent non-parametric statistical method of Kruskal–Wallis was used. Where significant differences between the groups were detected, a multiple comparison test (Dunnetts test or Scheffes method) was applied. Final survival rates and the incidences of tumours were compared with the Fishers exact probability test.

Sex:

male

Dose descriptor:

LD50

Effect level:

> 2 200 mg/kg bw

Based on:

test mat.

Remarks on result:

other: calculated from test material in diet fed over 104 weeks

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 500 mg/kg bw

Based on:

test mat.

Remarks on result:

other: calculated from test material in diet fed over 104 weeks

Mortality:

No significant differences in final survival rate and mean survival time were observed among the groups.

Clinical signs:

other: No treatment-related clinical signs were noted during the treatment period, except that growth supression and soft faeces in the 5% males and females were found throughout the experimental period.

Gross pathology:

For details on gross pathology refer to Sec 7.5.1: DL.K2.104Wk.Feed.RD/CARC.Pub.KD

Other findings:

For additional details refer to Sec 7.5.1: DL.K2.104Wk.Feed.RD/CARC.Pub.KD

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 > 2200 mg/kg in males; LD50 > 2500 mg/kg in females

Executive summary:

The two year carcinogenicity of the test substance was examined in groups of 50 male and 50 female F344 rats at dietary doses of 0% (control), 2.5% and 5%. Growth suppression and soft faeces were observed in male and female rats of the 5% group. However, no significant differences from the controls were noted with regard to clinical signs, mortality and haematological findings. None of the treated groups showed significant increase in the incidence of any specific tumour over the control group level. In conclusion, the present results demonstrate that the test substance dose not exert any carcinogenic potential in male and female F344 rats fed for two years. The LD₅₀ was calculated from the 104-week study to be >2200 mg/kg in males and >2500 mg/kg in female rats.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 500 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The test substance has low oral toxicity in the rat. The oral LD₅₀ was > 2200 mg/kg in male rats and >2500 mg/kg in female rats.

Physicochemical and toxicological properties of D-xylose do not suggest a potential for a significant rate of absorption. Further, xylose has been extensively reviewed and approved for human consumption. In addition, within all the years of xylose being used in foodstuffs and being supplied to numerous sectors, whereby it is handled, there has never been a report regarding toxicological concerns upon dermal exposure. The toxicity of xylose has been studied extensively, including an oral two-year study, and no systemic toxicity has been demonstrated. 

Justification for classification or non-classification

Based on the acute male rat oral LD50 of > 2200 mg/kg and acute female rat oral LD50 of >2500 mg/kg, no classification is required for acute oral toxicity according to EU Classification and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.

Physicochemical and toxicological properties of D-xylose do not suggest a potential for a significant rate of absorption. Further, xylose has been extensively reviewed and approved for human consumption. In addition, within all the years of xylose being used in foodstuffs and being supplied to numerous sectors, whereby it is handled, there has never been a report regarding toxicological concerns upon dermal exposure. The toxicity of xylose has been studied extensively, including an oral two-year study, and no systemic toxicity has been demonstrated. Therefore, no classification is required for acute dermal toxicity according to EU Classification and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.

Data lacking due to waiving arguments, so substance cannot be classified for acute inhalation toxicity according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.