Registration Dossier

Administrative data

Description of key information

The acute oral LD50 of AC-6000 is >2500 mg/kg bw. The acute inhalation LC50 of AC-6000 is >139.7 mg/L (analytical concentration) / >153.7 mg/l (nominal concentration). The acute dermal LD50 of AC-6000 is >2000 mg/kg bw.

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other: GLP compliant guideline study, available as unpublished report, no restrictions, fully adequate for assessment.
Qualifier:
according to guideline
Guideline:
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
Qualifier:
according to guideline
Guideline:
EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)
GLP compliance:
yes (incl. QA statement)
Test type:
acute toxic class method
Limit test:
yes
Species:
rat
Strain:
Sprague-Dawley
Sex:
female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River (UK) Ltd, Margate, Kent, UK
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 201-218 g
- Fasting period before study: overnight fast and three to four hours after dosing
- Housing: groups of three in suspended solid-floor polypropylene cages furnished with woodflakes
- Diet: Certified Rat and Mouse Diet (Code 5LF2) supplied by BCM IPS Limited, London, UK (ad libitum)
- Water: mains drinking water (ad libitum)
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25
- Humidity (%): 30-70
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12 / 12
Route of administration:
oral: gavage
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
MAXIMUM DOSE VOLUME APPLIED: 1.29 mL/kg
Doses:
2000 mg/kg bw
No. of animals per sex per dose:
6
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations 0.5, 1, 2 and 4 hours after dosing and subsequently once daily up to 14 days; weighing prior to dosing and 7 and 14 days after treatment
- Necropsy of survivors performed: yes
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
> 2 500 mg/kg bw
Based on:
test mat.
Mortality:
There were no deaths.
Clinical signs:
There were no signs of systemic toxicity.
Body weight:
All animals showed expected gains in bodyweight over the study period.
Gross pathology:
No abnormalities were noted at necropsy.
Interpretation of results:
GHS criteria not met
Conclusions:
The acute median lethal dose (LD50) of the test material in the female Sprague-Dawley CD strain rat was estimated to be > 2500 mg/kg bodyweight.
Executive summary:

The study was performed to assess the acute oral toxicity of the test material following a single oral administration in the Sprague-Dawley CD strain rat in accordance with OECD Guideline 423 (Acute Oral toxicity – Acute Toxic Class Method). Six fasted females (3 females/group) were administered the undiluted test material orally at a dose level of 2000 mg/kg bodyweight. All animals showed expected bodyweight gains, and no signs of systemic toxicity, deaths, or abnormalities at necropsy were observed. The acute median lethal dose (LD50) of the test material in the female Sprague-Dawley CD strain rat was estimated to be > 2500 mg/kg bodyweight.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
2 500 mg/kg bw

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:
other: GLP compliant guideline study, available as unpublished report, no restrictions, fully adequate for assessment.
Qualifier:
according to guideline
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Qualifier:
according to guideline
Guideline:
EU Method B.2 (Acute Toxicity (Inhalation))
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.1300 (Acute inhalation toxicity)
GLP compliance:
yes
Test type:
standard acute method
Limit test:
no
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Harlan UK Limited, Bicester, Oxon, OX25 1TP, UK
- Age at study initiation: 8-12 weeks
- Weight at study initiation: Males 243–297 g, Females 172–193 g
- Fasting period before study: during exposure
- Housing: 5 per cage, sexes separately, in multiple rat racks suitable for animals of this strain and the weight range expected during the course of the study. Additional animals for trial exposures were housed 2 per cage, sexes separately.
- Diet: Diet (RM1) supplied by Special Diets Services Limited, Witham, Essex, UK (ad libitum)
- Water: mains water, supplied by an automatic system (ad libitum)
- Acclimation period: at least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±3
- Humidity (%): 30-70
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12 / 12
Route of administration:
inhalation: vapour
Type of inhalation exposure:
nose only
Vehicle:
clean air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The test atmosphere was generated using a large glass condenser column and large round bottomed flask. The test substance was delivered to the heated glass column using a Watson Marlow pump (pump speed 4%). The pump tubing size was 817743. The glass condenser column was heated to approximately 50°C using a Techne water bath.
- Exposure chamber volume: Approximately 9.2 L. The chamber located on to a base-plate, fitted with castors for maneuverability. A conical aluminium lid ensured good distribution of the atmosphere across the chamber, the atmosphere having being generated from above. The conical lid and the base together had a volume of approximately 9.2 L. In this study two sections were connected, giving a total chamber volume of approximately 27.6 L.
- Method of holding animals in test chamber: Animals were restrained in polycarbonate tubes supplied by Battelle, Geneva, Switzerland
- Source and rate of air: Clean, dry air (dried and filtered using equipment supplied by Atlas-Copco, Sweden), at a flow rate of 20 L/min
- Temperature, humidity, pressure in air chamber: 21.2-21.5ºC and 15-30%. Pressure has not been measured.

TEST ATMOSPHERE
- Brief description of analytical method used: The test atmospheres were sampled manually using gas tight syringes and analysed using gas chromatography. Each test atmosphere was analysed regularly during each exposure period. The analysis system was calibrated using an appropriate range of freshly prepared standards prior to the study and at intervals thereafter. The peaks obtained were used to calculate the atmosphere concentrations. Control atmospheres and room air were also sampled and analysed.
- Samples taken from breathing zone: yes

SELECTION OF TEST CONCENTRATIONS
- Rationale for the selection of the starting concentration: An atmospheric concentration of 1400 ppm (20 mg/L), a limit test concentration as recommended by a number of national and international guidelines on toxicity testing was selected as the initial target exposure level. A higher dose level was requested by the sponsor to generate safety data relevant to human exposure.
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
Target concentration: 1400 and 10000 ppm
Analytical concentration: 1443 and 9631 ppm (20.9 and 139.7 mg/L)
Nominal concentration: 1576 and 10594 ppm (22.85 and 153.7 mg/L)
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 and weighing: observations during exposure, immediately after exposure and at the end of the observation period; weighing on day -1, 1, 8 and 15
- Necropsy of survivors performed: yes
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 10 000 other: ppm (target)
Based on:
test mat.
Exp. duration:
4 h
Key result
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 139.7 mg/L air (analytical)
Based on:
test mat.
Exp. duration:
4 h
Key result
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 153.7 mg/L air (nominal)
Based on:
test mat.
Exp. duration:
4 h
Mortality:
There were no deaths during the exposure or observation periods.
Clinical signs:
other: see "other findings"
Body weight:
All animals had gained weight by day 15 of the study. The majority of animals had gained weight by day 8 and continued to gain weight to the end of the study, except for 2 females that did not increase in weight between day 1 - 8 and also 1 male that lost weight between day 1 – 8.
Gross pathology:
There were no treatment related macroscopic abnormalities.
Only one finding was noted at necropsy – one male animal had 50% reduced left testis and epididymis.
Other findings:
Observations during exposure Abnormalities generally associated with restraint (wet fur) were observed in all animals during exposure. Most animals had stains around the snout. Changes indicative of mild irritation of the upper respiratory tract (irregular breathing) were observed in all animals dosed at 10000 ppm.
Interpretation of results:
GHS criteria not met
Conclusions:
No deaths or adverse effects were observed with nose-only exposure to the test material at target concentrations of 19.93 mg/L (1400 ppm) or 142.37 mg/L (10000 ppm). Nominal/analytical concentrations were 22.85 mg/L (1576 ppm) / 20.90 mg/L (1443 ppm) and 153.7 mg/L (10594 ppm) / 139.7 mg/L (9631 ppm). Therefore, the median lethal concentration of AC-6000 is > 153.7 mg/L (nominal) / 139.7 mg/L (analytical).
Executive summary:

The 4-hour acute inhalation toxicity study was conducted according to OECD 403: Acute Inhalation Toxicity guidelines. Male and female Wistar rats were exposed to vaporised AC-6000 for 4 hrs at nominal/analytical concentrations of 22.85 mg/L (1576 ppm) / 20.90 mg/L (1443 ppm) and 153.7 mg/L (10594 ppm) / 139.7 mg/L (9631 ppm). No deaths or severe toxicity was observed. Non-specific findings associated with restraint (wet fur) were detected at both target concentrations, and breathing irregularities were noted during exposure to the target 10000 ppm concentration. All animals had gained weight by day 15 of the study. No macroscopic findings related to the lung were observed at necropsy, and findings in the testes and epididymis of the same animal were not considered to be treatment related.  Therefore, the median lethal concentration of AC-6000 is > 153.7 mg/L (nominal) / 139.7 mg/L (analytical).

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LC50
Value:
139 700 mg/m³

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: GLP compliant guideline study, available as unpublished report, no restrictions, fully adequate for assessment.
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Qualifier:
according to guideline
Guideline:
EU Method B.3 (Acute Toxicity (Dermal))
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.1200 (Acute Dermal Toxicity)
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: 8 weeks
- Weight at study initiation: 244-259 g (males); 166-188 g (females)
- Fasting period before study: no
- Housing: individually housed in labeled Macrolon cages (Mill type, height 18 cm) containing sterilized sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France) and paper as cage-enrichment (Enviro-dri, Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom)
- Diet: pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten, GbmH, Soest, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.5-21.6
- Humidity (%): 31-58
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12
Type of coverage:
occlusive
Vehicle:
unchanged (no vehicle)
Details on dermal exposure:
TEST SITE
- Area of exposure: 25 cm2 (males); 18 cm2 (females)
- % coverage: 10
- Type of wrap if used: Surgical gauze patch (Surgy 1D), covered with aluminum foil and Coban elastic bandange. Micropore tape was additionally used for fixation of the bandages in females only.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes, using tap water
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied: 1.287 mL/kg bw
- Constant volume or concentration used: yes
Duration of exposure:
24 hours
Doses:
2000 mg/kg bw
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 and weighing: observations at periodic intervals on the day of dosing (day 1), and once daily thereafter until day 15; weighing on day 1, 8, 15 and at death
- Necropsy of survivors performed: yes
Key result
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
One male was found dead on day 2. No further mortality occurred.
Clinical signs:
The males showed hunched posture, ptosis, chromodacryorrhea and/or flat posture on days 1 and 2. Two females showed chromodacryorrhea on days 1 and/or 2.
Body weight:
The changes noted in body weight gain in males and females were within the range expected for rats used in this type of study and were therefore considered not indicative of toxicity.
Gross pathology:
No abnormalities were found at macroscopic post mortem examination of the animals.
Other findings:
Scabs were seen in the treated skin-area of one male during the study period.
Interpretation of results:
GHS criteria not met
Conclusions:
The dermal LD50 of AC-6000 in Wistar rats is >2000 mg/kg body weight.
Executive summary:

The acute dermal toxicity study was conducted in accordance with OECD 402 (Acute Dermal Toxicity), EU Method B.3 (Acute Toxicity (Dermal)), and EPA OPPTS 870.1200 (Acute Dermal Toxicity) guidelines. AC-6000 was applied dermally to male and female Wistar rats. The test substance was held in place for 24 hrs to an area approximately 10% of the total body surface, after which dressings were removed and residual test substance washed off with tap water. One male was found dead on Day 2. No further mortality occurred. On Days 1 and/or 2 males showed hunched posture, ptosis, chromodacyorrhea and/or flat posture, and two females showed chromodacryorrhea. One male had scabs on the treated skin-area. Changes in body weight were within the range expected for rats used in this type of study, and were not considered indicative of toxicity. There were no macroscopic abnormalities found at necropsy. Therefore, the dermal LD50 of AC-6000 in Wistar rats is >2000 mg/kg body weight.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
2 000 mg/kg bw

Additional information

Acute oral toxicity


 


In a GLP compliant study according to OECD guideline 423 and EU method B.1 the acute oral toxicity of AC-6000 following a single oral administration in the Sprague-Dawley CD strain rat was investigated (SafePharm Laboratories, 2006).


A group of three fasted females was treated with AC-6000 at a dose level of 2000 mg/kg bw by gavage. This was followed by a further group of three fasted females at the same dose level. The test material was administered orally undiluted. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy.


There were no deaths or signs of systemic toxicity. All animals showed expected gains in bodyweight over the study period. No abnormalities were noted at necropsy.


The acute oral median lethal dose (LD50) of the test material in the female Sprague-Dawley CD strain rat was estimated to be greater than 2500 mg/kg bw.


 


Acute inhalation toxicity


 


In a GLP compliant study according to OECD guideline 403 and EU method B.2 the acute inhalation toxicity of AC-6000 following a single four-hour inhalation period in the Wistar strain rat was investigated (Syngenta Central Toxicology Laboratory, 2007). Two groups, each containing five male and five female animals, were exposed nose-only to AC-6000 at a target concentration of either 1400 ppm (analytical concentration of 1443 ppm / 20.9 mg/L) or 10000 ppm (analytical concentration of 9631 ppm / 139.7 mg/L). Following exposure, the animals were retained without treatment for 14 days. Clinical observations and bodyweights were recorded throughout the study and at the end of the scheduled period, the animals were killed and subjected to a gross examination.


No animals died during the study. Clinical findings were mainly confined to observations associated with restraint (wet fur) with only transient irregular breathing noted in animals during exposure to the highest concentration. All animals gained weight during the study. At necropsy, no treatment related macroscopic findings were noted.


Nose-only exposure for 4 hours to target concentrations of 1400 ppm (analytical concentration of 1443 ppm / 20.9 mg/L) or 10000 ppm (analytical concentration of 9631 ppm / 139.7 mg/L) resulted in no deaths and no adverse effects. It is concluded that the median lethal concentration of AC-6000 exceeds 10000 ppm (analytical concentration of 9631 ppm / 139.7 mg/L).


 


Acute dermal toxicity


 


In a GLP compliant study according to OECD guideline 402 and EU method B.3, the acute dermal toxicity of AC-6000 following a single dermal application for 24 hours in the Wistar strain rat was investigated (NOTOX B.V., 2008). A group of five male and five female animals were exposed to AC-6000 at a dose level of 2000 mg/kg bw. Animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed on the day of death or after terminal sacrifice (day 15).


On male was found dead on day 2. No further mortality occurred. The males showed hunched posture, ptosis, chromodacryorrhea and/or flat posture on days 1 and 2. Two females showed chromodacryorrhea on days 1 and/or 2. Scabs were seen in the treated skin-area of one male during the study period. The changes noted in body weight gain in males and females were within the range expected for rats used in this type of study. No abnormalities were found at macroscopic post mortem examination of the animals.


The dermal LD50 value of AC-6000 in Wistar rats was established to exceed 2000 mg/kg bw.

Justification for classification or non-classification

Based on the results of the acute oral, inhalation and dermal toxicity studies, classification according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 is not needed.