2,4,8,10-tetra(tert-butyl)-6-hydroxy-12H-dibenzo[d,g][1,3,2]dioxaphosphocin 6-oxide, sodium salt

Endpoint summary

Description of key information

Acute Toxicity:

Oral: LD50> 2000 mg/kg b.w. for rat (OECD 423)

Dermal: LD50> 2000 mg/kg b.w. for rat (OECD 402, 24h exposure)

Inhalation:  LC50= 3110 mg/m³ for rat, with the analogous read-across substance NA-70 (OECD 403, 4 h exposure)

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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented and reported study fully adequate for assessment. The study was conducted according to internationally accepted technical guidelines and in compliance with GLP in a recognized contract research organization.

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

of 1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Rats, Sprague Dawley origin (Hsd: Sprague-Dawley (CD))
- Source: Harlan U.K. Ltd., Bicester, Oxon, England
- Age at study start (day of dosing): 5 to 7 weeks.
- Weight at start (day of dosing): minimum 118 g, maximum 141 g.
- Fasting period: Overnight prior to dosing, until ca. 4 hours post administration.
- Housing: In groups of 3 by sex in metal cages with wire mesh floors.
- Diet: standard rodent diet (Special Diet Services RM1(E) SQC expanded pellet), ad libitum
- Drinking water : drinking water ad libitum
- Acclimation period: min. 5 days before dosing.

Routine analysis of the batch of diet used, water and chew blocks did not provide evidence of contamination that might have prejudiced the study.

ENVIRONMENTAL CONDITIONS

- Temperature (°C): 22 ± 3°C
- Relative Humidity (%): 40 to 70%
- Photoperiod (artificial lighting): 12 hrs day / 12 hrs night

There were no deviations from these ranges, which compromised the quality, integrity or outcome of the study.

Route of administration:

oral: gavage

Vehicle:

methylcellulose

Remarks:

1% w/v acqueous preparation

Details on oral exposure:

DOSE FORMULATION AND DOSE VOLUME:

- Concentration of test material in vehicle: 200 mg/mL
- Amount (dose volume by gavage): 10 mL/kg bw

Preparation of the test material on the day of dosing.

ACUTE TOXIC CLASS METHOD - Rationale for the selection of the starting dose:
The starting dose was 2000 mg/kg bw., conduction not reported.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3 females
3 males

Control animals:

no

Details on study design:

- Duration of observation period: 14 days after dosing (day 1)
- Frequency of observations and weighing: observation of clinical signs after dosing, at frequent intervals of this day 1, day 2-14 twice daily,
day 15 in the morning;
weighing day 1 (prior to dosing), 8 and 15
- Necropsy performed: yes
- other examinations performed: macroscopic pathology

Statistics:

Not applicable, as there were no deaths and only one dose group.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No deaths at 2000 mg/kg bw

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no deaths at 2000 mg/kg bw

Mortality:

Dose level Mortality
2000 mg/kg 0/3 (f)
2000 mg/kg 0/3 (m)

Clinical signs:

other: Piloerection and loose faeces were seen in all animals from Day 1; females approximately 1-2 hours post dose, males approximately 3 hours post dose. Hunched posture in all females from Day 1(from approximately 3 hours post dose). Recovery of rats, as judg

Gross pathology:

No abnormalities were revealed at the macroscopic examination at study termination on Day 15.

Interpretation of results:

other: LD50 > 2000 mg/kg

Conclusions:

No labelling regarding acute oral toxicity according to Regulation (EC) No 1272/2008 is required.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

(1981) Method B2, Commission Directive 92/69/EEC

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS: Sprague-Dawley Crl:CD® (SD) IGS BR
- Source:Charles River (UK) Ltd, Margate, Kent
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 200g - 350g
- Fasting period before study: none
- Housing:in groups of five by sex in solid-floor polypropylene cages with stainless steel lids, furnished with softwood flakes and provided with environmental enrichment items: wooden chew blocks
- Diet (e.g. ad libitum): ad libidtum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: min. 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25°C
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

clean air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: SAG 410 Solid Aerosol Generator (TOPAS GmbH, Dresden, Germany)
- Exposure chamber volume: 30 l
- Method of holding animals in test chamber: tapered, polycarbonate restraining tube fitted onto a single tier of the exposure chamber
- Source of air: Compressed air, passed through a water trap and respiratory quality filters
- Method of particle size determination: Marple Personal Cascade Impactor, (Westech IS Ltd, Beds., UK); six impactor stages (9.6, 6.6, 3.5, 1.8, 0.87
and 0.33 μm cut points
- Treatment of exhaust air: passed through a scrubber trap, connected with a filter

- Samples taken from breathing zone: yes

TEST ATMOSPHERE (see Any other information on materials and methods incl. tables, table 1)

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetric method

Duration of exposure:

4 h

Concentrations:

see Any other information on materials and methods incl. tables, table 1

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: hourly during exposure, at the end of exposure and 1h later. Once daily up to 14 days.
and weighing: prior to exposure on the day of treatment, days 7 and 14.
- Necropsy performed: yes (all animal, surviving, died, killed)
- Other examinations performed: clinical signs, body weight, macroscopic examination, esp. of the respiratory tract, behavioural observations

Statistics:

LC50’s estimated by Linear Interpolation (US EPA, 1989)

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

3.11 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

see Any other information on results incl. tables, table 2

Clinical signs:

other: Common abnormalities:increased respiratory rate, hunched posture, pilo-erection and wet fur. Frequent instances of decreased respiratory rate, laboured respiration, noisy respiration, ataxia and red/brown staining around the head. Occasional instances of

Body weight:

Normal bodyweight development for all surviving animals during the study with the following exeptions:
Group 1: 1 male and 1 female showed reduced bodyweight gain or slight bodyweight loss during Week 1 but recovered to show normal development during Week 2. A further female from Group 1 showed slight bodyweight loss during Week 2.
Group 2: 5 females exhibited a reduced bodyweight gain or slight bodyweight loss during Week 1 but recovered to show normal development during Week 2.

Gross pathology:

Macroscopic abnormalities detected amongst
- animals that survived until Day 14 at necropsy:
Lungs – enlarged, fluid filled, abnormally dark, pale patches, dark patches (in all animals of the low and mid dose groups);
- animals that died or were humanely killed during the course of the study at necropsy:
Lungs – haemorrhagic, fluid filled, abnormally dark, pale patches;
Liver – dark;
Kidneys – dark or pale;
Stomach – gaseous distension; Small Intestine – gaseous distension; Large Intestine – gaseous distension.

Table 2: Mortality data

Group Number	Mean Achieved Atmosphere Concentration (mg/L)		Deaths
		Male	Female	Total
1	1.00	0/5	0/5	0/10
2	1.96	2/5	0/5	2/10
3	5.03	5/5	5/5	10/10

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Acute Toxicity Inhalation Category 4, H332: [Regulation (EC) No 1272/2008]

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

3 110 mg/m³ air

Quality of whole database:

The acute inhalation study with the read across substance (lithium salt instead of sodium salt within the reviewed substance), conducted with rats in 2006, is reliable and of adequate quality.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented and reported study fully adequate for assessment. The study was conducted according to internationally accepted technical guidelines and in compliance with GLP in a recognized contract research organization.

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

GLP compliance:

yes (incl. QA statement)

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Sprague-Dawley origin (Hsd:Sprague-Dawley (CD))
- Source: Harlan U.K. Ltd., Bicester, Oxon, England.
- Age at study initiation: 8 - 11 weeks
- Weight at study initiation: 221 - 260 g
- Housing: individually in metal cages (RS Biotech Sub-Dividable Rodent Cages - polished stainless steel) until Day 4 when they were returned to group housing. Cages fitted with grid floors.
- Diet (e.g. ad libitum): standard laboratory rodent diet (Special Diet Services RM1(E) SQC expanded pellet)
- Water (e.g. ad libitum): drinking water
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3°C
- Humidity (%): 40 - 70%
- Photoperiod (hrs dark / hrs light): 12h/12h

Type of coverage:

occlusive

Vehicle:

other: 48% aqueous methycellulose

Details on dermal exposure:

dorso-lumbar region
- Area of exposure: approximately 50 mm x 50 mm
- % coverage: 10
- Type of wrap if used: waterproof dressing (encircled firmly around the trunk of the animal)

REMOVAL OF TEST SUBSTANCE
- Washing (if done): with warm water (30-40°C), blotted dry with absorbent paper
- Time after start of exposure: 24h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw
- Concentration (if solution):48% w/v
- Constant volume or concentration used: yes
- For solids, paste formed: yes

VEHICLE
- Amount(s) applied (volume or weight with unit): 4,17 ml

Duration of exposure:

24 h

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

10 rats (5 of each sex)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observation of clinical signs after dosing, at frequent intervals of this day 1, day 2-14 twice daily,
day 15 in the morning, local dermal irritation daily observed
weighing day 1 (prior to dosing), 8 and 15
- Necropsy of survivors performed: yes
- Other examinations performed: local dermal irritation (erythema, eschar formation, oedema formation), any other lesion or reaction (spots, scabbing)

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

none

Clinical signs:

other: none

Gross pathology:

no abnormalities

Other findings:

dermal reactions: very slight dermal irritation (erythema and/or oedema), resolving completely on day 4. Scabbing and/or spots in 3 females on day 6, resolving completely by day 7, 9, 11.

Interpretation of results:

other: LD50 > 2000 mg/kg

Conclusions:

No labelling regarding acute dermal toxicity according to Regulation (EC) No 1272/2008 is required.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The acute dermal toxicity study with the testing substance, conducted with rats in 2001, is reliable and of adequate quality.

Justification for classification or non-classification

In both, the acute oral and the acute dermal toxicity studies with NA-11, all animals survived the limit dose of 2000 mg/kg b.w. Therefore, classification for acute oral or dermal toxicity is not required [REGULATION (EC) 1272/2008].

 

According to the result of the acute inhalation toxicity study NA - 11 has to be classified as acute toxic category 4 (Regulation (EC) 1272/2008).