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Description of key information

Read-across from data on acute oral and acute dermal toxicity on cetrimonium chloride  indicates that cetrimonium bromide should be classified as Acute tox 4 for acute oral toxicity based on LD50 values for cetrimonium chloride in the range of 465 - 891 mg/kg bw.  A dermal LD50 value of 4.3 ml/kg bw was found  (corresponding to 2150 mg/kg bw ) which is above the CLP classification criteria.

A 30 minutes inhalation study with mice indicates pulmonary irritation as dose-related reduced tidal volume and increase in respiratory frequency was found with a LOEC of 1.8 mg cetrimonium bromide/m3 and a NOEC of 0.57 mg cetrimonium bromide/m3 .  Initial signs of pulmonary inflammation were found at 19 mg cetrimonium bromide/m3 based on an increase in macrophages in BAL. Thus it is considered relevant to apply classification with STOT SE3; H335.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records
Reference
Endpoint:
acute toxicity: oral
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Read-across to cetrimonium bromide from data on cetrimonium chloride (with data reliability value of 1). Read-across justifications are provided in the endpoint summary.
Qualifier:
according to
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
no
Species:
rat
Strain:
Wistar
Sex:
male/female
Route of administration:
oral: gavage
Vehicle:
water
Doses:
630 (only females), 1000, 1600, 2500, 3150 (only males) and 4000 (only males)
No. of animals per sex per dose:
5
Control animals:
not specified
Details on study design:
The test substance was applied by oral gavage at dosages of 630, 1000, 1600, 2500, 3150,
and 4000 mg/kg bw to groups of 5 male and/or 5 female rats. The lowest dose was
administered to 5 females only. The two highest doses were administered to male rats only.
The animals were checked daily for mortality and clinical signs. Body weights were recorded
at start and on days 7 and 14. Animals were observed for 14 days. Animals that died during
the test and all surviving animals at the end of the observation period were submitted to
gross necropsy.
Statistics:
The LD50 values were for the test substance calculated to be 2970 and 1550 mg/kg bw for male and female rats, respectively (test substance: 28-30% cetrimonium chloride) . I.e LD50 values calculated as 100% cetrimonium chloride: 891 mg/kg bw and 465 mg/kg.
Sex:
male
Dose descriptor:
LD50
Effect level:
ca. 2 970 mg/kg bw
Based on:
dissolved
Remarks:
28-30% cetrimonium chloride in water
Sex:
female
Dose descriptor:
LD50
Effect level:
ca. 1 550 mg/kg bw
Based on:
dissolved
Remarks:
28-30% cetrimonium chloride in water
Mortality:

Dosage mortality male rats mortality female rats

630 not tested 1/5
1000 1/5 1/5
1600 0/5 2/5
2500 0/5 4/5
3150 3/5 not tested
4000 5/5 not tested
Clinical signs:
During the first days after administration, animals of all treated groups showed decreased
motor activity, squatting posture, sunken flanks, half-closed eyes, piloerection, pale skin,
laboured irregular respiration, miosis and diarrhoea. All clinical signs had completely ceased
by day 10.
Animals that had died during the study showed bleeding of the stomach mucosa, inflated
stomach, white and/or partially detached stomach mucosa, hyaline aspect of the small
intestine, reddened small intestinal mucosa, dark stained adrenals and lung haemorrhage.
Gross pathology:
No macroscopic alterations were observed in rats that had survived until the end of the
observation period.
Interpretation of results:
Toxicity Category IV
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The LD50 values were calculated to be 2970 and 1550 mg/kg bw (test substance 28-30% cetrimonium chloride in water) for male and female rats, respectively.
Read across from these data on cetrimonium chloride to cetrimonium bromide indicates according to the CLP criteria that cetrimonium bromide should be classified as Acute tox. 4; H302.
Executive summary:

The test substance (test substance 28-30% cetrimonium chloride in water) was administered by oral gavage at dosages of 630, 1000, 1600, 2500, 3150, and 4000 mg/kg bw to groups of 5 male and/or 5 female rats. The lowest dose was administered to 5 females only. The two highest doses were administered to male rats only. The animals were checked daily for mortality and clinical signs. Body weights were recorded at start and on days 7 and 14. Animals were observed for 14 days. Animals that died during

the test and all surviving animals at the end of the observation period were submitted to gross necropsy.

During the first days after administration, animals of all treated groups showed decreased motor activity, squatting posture, sunken flanks, half-closed eyes, piloerection, pale skin, laboured irregular respiration, miosis and diarrhoea. All clinical signs had completely ceased by day 10. Except for one male of the 1000-mg/kg bw group that was found dead on day 13, all deaths

occurred within the first 5 days. The LD50 values (test substance 28-30% cetrimonium chloride in water) were calculated to be 2970 and 1550 mg/kg bw for male and female rats, respectively. I.e. LD50 values calculated as 100% cetrimonium chloride: 891 mg/kg bw and 465 mg/kg bw.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
Value:
465 mg/kg bw
Quality of whole database:
Klimisch Score 1 on the read across substance

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: Well described study published in a peer reviewed scientific journal.
Qualifier:
no guideline followed
Principles of method if other than guideline:
30 minutes inhalation head only exposure of aerosols
GLP compliance:
not specified
Test type:
other: 30 min inhalation exposure
Species:
mouse
Strain:
Balb/c
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Taconic, Silkeborg Denmark
- Weight at study initiation: Mean weight 19.4g; SD 1.7g
- Housing: Polypropylene cages with pinewood sawdust bedding
- Diet: ad libitum
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±2 °C
- Humidity (%): 50±5%
- Photoperiod (hrs dark / hrs light): From 6 am to 6 pm
Route of administration:
inhalation: aerosol
Type of inhalation exposure:
head only
Vehicle:
other: saline water
Details on inhalation exposure:
Mice were placed in separate body plethysmographs and exposed to a saline aerosol for 15 min followed by an exposure period of 30 min. Hereafter exposed to clean air for 45 min for recovery.
Analytical verification of test atmosphere concentrations:
yes
Remarks:
gravimetric measurement of aerosols
Duration of exposure:
30 min
Concentrations:
control: 0 mg/m3
exposure level 1: 0.33% cetrimonium bromide solution generating exposure level of 0.57 mg cetrimonium bromide /m3
exposure level 2: 1% cetrimonium bromide solution generating exposure level of 1.8 mg cetrimonium bromide /m3
exposure level 3: 3.3% cetrimonium bromide solution generating exposure level of 5.3 mg cetrimonium bromide /m3
exposure level 4: 10% cetrimonium bromide solution generating exposure level of 19 mg cetrimonium bromide /m3
No. of animals per sex per dose:
7-8 animals per dose level
Control animals:
yes
Details on study design:
Observation of respiratory parameters was done during exposure (respiratory rate; tidal volume).
Airway inflammation was examined 16 hours after end of exposure by examination of BAL (Bronchoalveolar lavage fluid).

Observation of respiratory parameters
Sex:
female
Dose descriptor:
other: LOEC
Effect level:
1.8 mg/m³ air
Based on:
test mat.
Exp. duration:
30 min
Remarks on result:
other: Based on reduced tidal volume
Sex:
female
Dose descriptor:
other: NOEC
Effect level:
0.57 mg/m³ air
Based on:
test mat.
Exp. duration:
30 min
Remarks on result:
other: Based on tidal volume
Other findings:
Dose dependent decrease in tidal volume. Fully reversible for lower concentrations and only slightly reversible at the highest exposure level during the 45-min recovery period. The tidal volume reduction was time-dependent and concentration-dependent.
Also dose dependent increase in respiratory frequency.
As for other quaternary ammonium compounds tested in the study an increase in macrophages was observed in BAL (only at highest dose-level aand less pronounced as for benzalkoniium chloride)
Interpretation of results:
other: STOT SE 3 - H335
Remarks:
Criteria used for interpretation of results: EU
Conclusions:
Inhalation of cetrimonium bromide induced deep lung effects with decrease in tidal volume and increase in repsiratory frequency corresponidng effects known to occurrr from deep lung effects/ irritation (contrary to sensory irritation in the upper respiratory tract)) . As for other quaternary ammonium compounds tested in the study an increase in macrophages was observed in BAL (only at highest dose-level and less pronounced as for benzalkonium chloride) . The NOEL value based on reduction in tidal volume at 0.57 mg/m3 for inhalation of aerosols of cetrimonium bromide.
Executive summary:

The reported study examined the pulmonary effects ( irritation and inflammation) in connection with 30 minutes of inhalation of aerosols of quaternary ammonium compounds in mice. Inhalation of cetrimonium bromide induced dose related effects on tidal volume and respiratory frequency at a LOEC of 1.8 mg cetrimonium bromide /m3 as a response from deep lung effects and also induced initial signs in relation to lung inflammation (increased level of macrophages in BAL) at the highest test concentration (19 mg/m3). The NOEC value based on reduction in tidal volume was 0.57 mg/m3 for inhalation of aerosols of cetrimonium bromide.

These data indicate that classification as a respiratory irritant (STOT SE 3, H335) would be appropriate.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
discriminating conc.
Value:
1.8 mg/m³
Quality of whole database:
Klimisch score 2

Acute toxicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
Value:
4.3
Quality of whole database:
Klimisch score 2

Additional information

Justification for selection of acute toxicity – oral endpoint

Read across from two oral acute toxicity studies with rats (OECD 401 and OECD 420) on cetrimonium chloride.

Justification for selection of acute toxicity – inhalation endpoint

Only available study concerning inhalation of cetrimonium bromide. Non-guideline study determining pulmonary irritation and inflammation in mice  after  30 minutes of exposure.  The observed effects considered relevant for classification for respiratory (pulmonary) irritation, STOT SE3; H335.

Justification for selection of acute toxicity – dermal endpoint

Only available dermal acute toxicity study

Justification for classification or non-classification

Read-across from data on acute oral and acute dermal toxicity on cetrimonium chloride indicates that cetrimonium bromide should be classified as Acute tox 4 for actute oral toxicity based on LD50 values for cetrimonium chloride in the range of 465 - 891 mg/kg bw. A dermal LD50 value of 4.3 ml/kg bw was found which is above the CLP classification criteria.

A 30 minutes inhalation study with mice indicates pulmonary irritation as dose-related reduced tidal volume and increase in respiratory frequency was found with a LOEC of 1.8 mg cetrimonium bromide/m3 and a NOEC of 0.57 mg cetrimonium bromide/m3 . Initial signs of pulmonary inflammation were found at 19 mg cetrimonium bromide/m3 based on an increase in macrophages in BAL. Thus it is considered relevant to apply classification with STOT SE3; H335.