Quaternary ammonium compounds, dicoco alkyldimethyl, nitrites

Endpoint summary

Description of key information

Read across data is presented on the "fragments" from which this substance is manufactured :-

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides, CAS Number 68391-05-9, EC Number 269-924-1 and from sodium nitrite, CAS Number 7632-00-0, EC Number 231-555-9.

The justification in taking this approach is as follows :-

In the stomach the gastic juice is acidic, made up of acids and enzymes. In such an evironment it is highly unlikely that the quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites substance (s) will remain ionically bound to each other and thus are prone to dissociation in which case the released cation(s) will associate with other anions and the released anion will associate with cations. Thererfore, it is suggested read-across data from the corresponding quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides is considered approriate in that such substances are likely to dissociate in a similar manner.

Furthermore, in 1988, the US EPA, Office of Pesticides and Toxic Substances issued a Notice to producers, Formulators, Distributors and Registrants regarding quaternary ammonium compounds with regard to "Clustering" of such quaternary ammonium compounds.

Prior to this, EPA had required each quat compound to be individually coded and registered as a new chemical, even when the chemical structure of individual compounds differed only slightly in alkyl distribution and chain lengths. This procedure was continued with the new generations of quats having two, three, and four chains. As a result, EPA records showed that some 211 registered technical grade active ingredient products containing varying concentrations of Quats, each coded separately on the basis of alkyl chain length and percentage carbon distribution within the chain. At this time, there are approximately eight to ten thousands (8-10,000) registered end-use formulations.

However, questions were raised regarding whether the EPA could cluster or group the quats and pick one or more representative members of each cluster to be used in toxicity studies, instead of requiring separate studies on each quat. These same questions were raised when the EPA issued its March 4, 1987 Data Call-In Notice requiring all registrants of antimicrobial active ingredients to submit subchronic and chronic toxicological data to support the continued registration of their products.

In response to these questions, EPA solicited information from industry, the public, academia, industry cooperative work groups, the state of California, and Canada. EPA then reviewed all of the assembled information along with the chemical structure of most of the quats. Based on the results of this review, EPA developed the following four groupings of currently registered quat compounds:

Group I. The alkyl or hydroxyalkyl (straight chain) substituted Quats

Group II. The non-halogenated benzyl substituted Quats (includes hydroxybenzyl, ethylbenzyl, hydroxyethybenzyl, napthylmethyl, dodecylbenzyl, and alkyl benzyl)

Group III. The di-and tri-chlorobenzyl substituted

Group IV. Quats with unusual substituents (charged heterocyclic ammonium compounds).

Fundamental to this discussion EPA determined that "X-" in all of these structures would be attributed to "any anionic species". Therefore, this would mean in terms of toxicological evaluation the coutner anion in such quaternary ammonium compounds could be regarded as; e.g  halogen (Cl-, Br-, I-,), saccharinate or cyclohexylsulphamate. It is therefore suggested here that nitrite (NO2-) could also be regarded as a pertinent anion.

Since the US EPA deem that such a clustering of structures for toxicological evaluation is well founded then it would seem that to consider read-across data from quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides to the closely structurally analogous quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites to be equally justifiable.

Similarly since the US EPA deem that the counter anion could be regarded as "any anionic species" then it would seem that to consider available toxicological data on sodium nitrite, in order to evaluate any health effects that may be incurred from exposure to the nitrite anion (NO2-), is equally justifiable.

Furthermore, in certain organic solvents it has been reported that the exchange constants between nitrite and chloride in quaternary ammonium salts (QAS) are approximately equal. [Zhurnal Analiticheskoi Khimii, 2010, Vol. 65, No. 6, pp. 579–584. (E.M. Rakhman’ko, M.S. Markovskaya, L.S. Stanishevskii, Yu.S. Zubenko, A.R. Tsyganov)]

To that end one study is reported for Quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides, CAS Number 68391-05-9, EC Number 269-924 -, where the LD50 (oral) was determined to be 960 (630 to 1470) mg/kg bw and two studies are reported for sodium nitrite where the respective LD50s (oral) were deternined to be 214 mg/kg (males) and 216 mg/kg (females) in the first study and 180 mg/kg bw (males) in the second study.

Sodium nitrite has a lower LD50 in both studies, resulting in an acute oral toxicity, category 3, whereas that for quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides is an acute oral toxicity, Category 4.

However, the "nitrite" functionality present in quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites accounts for only approximately 7% of the substance and the "quaternary ammonium compounds, di-C12 -18 -alkyldimethyl fragment" accounts for approximately 93% of the substance. It is therefore envisaged that the contribution to the acute oral toxicity outcome will come overwhelmingly from the "quaternary ammonium compounds, di-C12 -18 -alkyldimethyl fragment".

The LD50 (oral) for quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites is estimated to be ca. 699 mg/kg bw resulting in an acute oral toxicity Category 4.

(In addition, NICNAS have also conducted a Human Health Tier II Assessment for sodium nitrite

In this assessment the LD50 (oral) is stated to be : -

85 mg/kg bw in rats, 175–216 mg/kg bw in mice, and 186 mg/kg bw in rabbits)

In addition, the acute inhalation toxicity of the test substance (containing cocobenzyldimethylammoniumchloride - 40% w/v, dicocodimethylammoniumchloride - 37.5 % w/v and water - 7.7 %) was investigated in a study conducted according to OECD guideline 403 and EPA-Guideline 81 -3 in compliance with GLP.

Four groups of ten rats each (five males and five females) were given a single, 4 h whole body exposure at concentration levels of 0, 0.17, 0.24 and 0.34 mg/L. The animals were observed for 21 d after the day of exposure and were then killed for gross and histopathological examination of the lungs. Body weight, food and water intake and lung weight were also determined.

There were no deaths in the control group; one animal (male) died at 0.17 mg/L, four animals died at 0.24 mg/L (3 males, 1 female), and nine animals died at 0.34 mg/L (5 males, 4 females). Clinical signs of toxicity noted were (partial) closing of the eyes and exaggerated respiratory movement during exposure in all test groups and gasping and wetness around the mouth during exposure at 0.34 mg/L. Clinical signs were noted in survivors throughout the 21 d observation period. Decrease of body weight, reduced body weight gain and reduced food and water intake was generally seen up to 14 d.

Abnormalities noted at necropsy in survivors were increased relative lung weight, swollen appearance of the lungs and gas-filled stomach and intestines. Animals that died showed congestion of the lungs, fluid in the trachea and gas-filled stomachs. Histopathological lung changes in survivors generally consisted of focal alveolitis and bronchiolitis; changes in deceased animals generally consisted of focal alveolar wall necrosis, diffuse congestion, focal alveolar wall oedema and focal alveolar wall haemorrhage.

Under the test conditions, the acute 4 h LC50 of the test material (containing cocobenzyldimethylammoniumchloride- 40% w/v, dicocodimethylammoniumchloride-37.5 % w/v and water 7.7 %) was found to be 0.25 mg/L (0.22 -0.28 mg/L) and it is classified as Category 2 according to CLP Regulation (EC 1272/2008).

Furthermore, a

study performed was performed according to GLP and OECD 402 and EU B.3 “Acute Dermal Toxicity” to investigate the dermal toxicity of didecyldimethylammonium chloride, CAS Number 7173 -51 -5, EC Number 230 -525 -2.

Five male and five female rats received a dermal dose of 2000 mg/kg bw for 24 h (dose volume: 10 ml/kg in distilled water) under occlusive dressing for 24 h. One day before exposure (day -1) an area of approximately 5x7 cm on the back of the animal was clipped.
24 h, after which dressings were removed and residual test substance removed using a tissue moistened with tap water.

Animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed after terminal sacrifice on day 15.

No mortality occurred. Effects noted were lethargy in all animals between day 2 and 4 and skin effects which consisted of swelling, redness, erythema and necrosis of the skin. The majority of the skin effects persisted until the end of the observation time. No abnormalities were found at macroscopic post mortem examination. Effects are limited to local irritation/corrosion of the skin, without involvement of systemic toxicity.

The acute dermal LD50 of the test substance in rats were determined to be >2000 mg/kg bw (i.e. >1000 mg a.i./kg bw).

As quaternary ammonium compounds do not easily pass biological membranes, dermal absorption of these compounds is very limited. The dermal toxicity of aqueous DDAC solutions is related to its corrosivety and therefore more related to the concentration of the administered solution than of the actual amount in mg/kg. Due to the direct corrosive effect, there is danger of irreversible damage to the skin upon exposure to the undiluted solution. Further toxicity is secondary to the local tissue damage, rather than the result of percutaneously absorbed material. Some reviews mention comparable dermal LD₅₀data in rat from literature which is in the range 2000 – 3000 mg/kg bw.

Toxicity is related to concentration dependent cytotoxicity, with a lack of specific systemic toxicity. The toxicity (and efficacy as based on same mechanism of action) show a dependence on chain length, with an optimum at C₁₀-C₁₂. Therefore this test using C₁₀-chainlength can be seen as worst case representative for the whole group of DDAC compounds between C₈and C₁₈.

Furthermore, additional tests for acute dermal toxicity are not ethical due to its corrosive effects and can thus not be performed.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

Read across justification is presented from the structurally analogous quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides to the quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites.

In the stomach the gastic juice is acidic, made up of acids and enzymes. In such an evironment it is highly unlikely that the quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites substance (s) will remain ionically bound to each other and thus are prone to dissociation in which case the released cation(s) will associate with other anions and the released anion will associate with cations. Thererfore, it is suggested read-across that data from the corresponding quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides is considered approriate in that such substances are likely to dissociate in a similar manner.

Furthermore, in 1988, the US EPA, Office of Pesticides and Toxic Substances issued a Notice to producers, Formulators, Distributors and Registrants regarding quaternary ammonium compounds with regard to "Clustering" of such quaternary ammonium compounds.

Prior to this, EPA had required each quat compound to be individually coded and registered as a new chemical, even when the chemical structure of individual compounds differed only slightly in alkyl distribution and chain lengths. This procedure was continued with the new generations of quats having two, three, and four chains. As a result, EPA records showed that some 211 registered technical grade active ingredient products containing varying concentrations of Quats, each coded separately on the basis of alkyl chain length and percentage carbon distribution within the chain. At this time, there are approximately eight to ten thousands (8-10,000) registered end-use formulations.

However, questions were raised regarding whether the EPA could cluster or group the quats and pick one or more representative members of each cluster to be used in toxicity studies, instead of requiring separate studies on each quat. These same questions were raised when the EPA issued its March 4, 1987 Data Call-In Notice requiring all registrants of antimicrobial active ingredients to submit subchronic and chronic toxicological data to support the continued registration of their products.

In response to these questions, EPA·solicited information from industry, the public, academia, industry cooperative work groups, the state of California, and Canada. EPA then reviewed all of the assembled information along with the chemical structure of most of the quats. Based on the results of this review, EPA developed the following four groupings of currently registered quat compounds:

Group I. The alkyl or hydroxyalkyl (straight chain) substituted Quats
Group II. The non-halogenated benzyl substituted Quats (includes hydroxybenzyl, ethylbenzyl, hydroxyethybenzyl, napthylmethyl, dodecylbenzyl, and alkyl benzyl)
Group III. The di-and tri-chlorobenzyl substituted
Group IV. Quats with unusual substituents (charged heterocyclic ammonium compounds).

Fundamental to this discussion EPA determined that "X-" in all of these structures would be attributed to "any anionic species". Therefore, this would mean in terms of toxicological evaluation the coutner anion in such quaternary ammonium compounds could be regarded as; e.g halogen (Cl-, Br-, I-,), saccharinate or cyclohexylsulphamate. It is therefore suggested here that nitrite (NO2-) could also be regarded as a pertinent anion.

Since the US EPA deem that such a clustering of structures for toxicological evaluation is well founded then it would seem that to consider read-across data from quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides to the closely structurally analogous quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites to be equally justifiable.

Furthermore, in certain organic solvents it has been reported that the exchange constants between nitrite and chloride in quaternary ammonium salts (QAS) are approximately equal. [Zhurnal Analiticheskoi Khimii, 2010, Vol. 65, No. 6, pp. 579–584. (E.M. Rakhman’ko, M.S. Markovskaya, L.S. Stanishevskii, Yu.S. Zubenko, A.R. Tsyganov)]

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

Standard acute method

GLP compliance:

no

Remarks:

Pre-GLP

Test type:

standard acute method

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): Arquad 2C
- Composition of test material, percentage of components: 75% dicocodimethylammonium chloride (CAS no. 68391-05-9), 15% isopropanol and 10% water
- Lot/batch No.: 1001702

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Sprague-Dawley, Madison, USA
- Age at study initiation: approximately 7 wk
- Weight at study initiation: 202-300 g
- Fasting period before study: Overnight
- Housing: 5 animals/sex/cage
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 7 d


ENVIRONMENTAL CONDITIONS
The animals were kept in temperature and humidity controlled quarters


IN-LIFE DATES: From: June 11, 1980 To: August 13, 1980

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED:
The average specific gravity of test material was 890 mg/mL and the highest dose level was 3200 mg/kg bw. The maximum volume given to the animals was, therefore, 2.85 mL/kg bw.

Doses:

270, 430, 670, 1050, 1310, 2050 and 3200 mg/kg bw

No. of animals per sex per dose:

8

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 d
- Frequency of observations and weighing: animals were observed 1, 2.5, and 4 h after dosing. After that the animals were observed daily for clinical signs and twice daily for mortality. The bodyweight of the animals were determined at Day 0, 7 and 14.
- Necropsy of survivors performed: yes
- Other examinations performed: no

Statistics:

No

Preliminary study:

Not applicable

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

930 mg/kg bw

Based on:

not specified

95% CL:

> 750 - < 1 140

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

1 000 mg/kg bw

Based on:

not specified

95% CL:

> 250 - < 4 090

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

960 mg/kg bw

Based on:

not specified

95% CL:

> 630 - < 1 470

Mortality:

No rats died in the 270 and 430 mg/kg bw groups. All rats died in the 2050 and 3200 mg/kg bw groups. There was a decreased level of mortality in the females at 1310 mg/kg bw compared to the two lower doses and to males at the same dose - see table below entitled ".Mortality rates in male and female rats administered the test substance by gavage".

Clinical signs:

other: Clinical signs such as diarrhoea, red stained around nose and mouth, hair loss, ataxia, decreased limb tone and hypoactivity were reported during the course of the study in most animals in the 670 mg/kg bw, 1050 mg/kg bw, 1310 mg/kg bw, 2050 mg/kg be and

Gross pathology:

- The major signs reported at necropsy in animals that died during the study were external signs of diarrhoea and bloody discharge from the nose, eyes and mouth.
- Adhesions involving the stomach and surrounding structures were seen at 1310 mg/kg bw, and were thought to suggest the presence of an inflammatory lesion involving the entire wall of the stomach with extension from the gastric serosa to adjacent tissues and healing fibrosis.
- Animals which received the higher dosage levels and died on test sooner possibly did not have adequate time for the lesion to develop. All other observations were considered incidental and not test related. A number of females that died during the study were partially cannibalised.

Mortality rates in male and female rats administered the test substance by gavage

Dose (mg/kg bw)	Male Mortality	Female Mortality
270	0/8	0/8
430	0/8	0/8
670	3/8	5/8
1050	6/8	5/8
1310	6/8	4/8
2050	8/8	8/8
3200	8/8	8/8

 

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Under the test conditions, the acute oral LD50 of test material (containing 75% dicocodimethyl ammonium chloride) in rats was determined to be 960 (630 to 1470) mg/kg bw and is classified as Category 4 for acute oral toxicity with the signal word "Warning" and is assigned the hazard statement H302 "Harmful if swallowed" according to CLP Regulation (EC 1272/2008).

Executive summary:

A study was performed with Sprague-Dawley rats to determine the acute oral toxicity of the test material (containing 75% dicocodimethyl ammonium chloride, 15% isopropanol and 10% water). The study was performed equivalent or similar to the OECD guideline 401. The study was not conducted according to GLP.

Consequently, this study is assigned a reliability score of 2 in accordance with the criteria for assessing data quality set forth by Klimisch et al (1997).

The test substance was administered undiluted by gavage to groups of 8 male and 8 female rats at dose levels of 270, 430, 670, 1050, 1310, 2050 and 3200 mg/kg bw. The animals were observed 1, 2.5, and 4 h after dosing. After that the animals were observed daily for clinical signs and twice daily for mortality. The bodyweight of the animals were determined at Day 0, 7 and 14. Necropsy was performed on all animals.

A decrease in bodyweight was observed for animals at higher dose levels.None of the animals of both sexes died at 270 and 430 mg/kg bw; all animals died at 2050 and 3200 mg/kg bw.In the surviving animals no specific lesions were detected. Some animals had discoloration of the lungs others showed mild hydrometra of the uterus, ulcer on the tail or adhesion of the non glandular region of the stomach to liver, spleen, cecum and abdominal wall. The signs observed in the animals that died during the study were: diarrhea, bloody nasal discharge or blood around the nose and mouth, bloody ocular discharge.

Under the test conditions, the acute oral LD50 of test material (containing 75% dicocodimethyl ammonium chloride) in rats was determined to be 960 (630 to 1470) mg/kg bw and is classified as Category 4 for acute oral toxicity with the signal word "Warning" and is assigned the hazard statement

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1950

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: See "Remarks"

Remarks:

This study is reported in a publication : Reimann, H., (1950). On the Toxicity of Hydroxylamine. Acta. Pharmacol. 6, 285-292. as the primary source. This is also referenced in the Screening Information Dataset Initiatl Assessment report for Sodium Nitrite (2005) as a secondary source, where it is reported as being reliable.

Justification for type of information:

Since in the stomach the gastic juice is acidic, made up of acids and enzymes, it is suggested that in this environment it is highly unlikely that the quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites substance (s) will remain ionically bound to each other and thus are prone to dissociation in which case the released cation(s) will associate with other anions and the released anion will associate with cations. Thererfore, it is suggested that read-across data from sodium nitrite is considered appropriate in order to arrive at a conclusion in terms of any health effects that may be incurred from exposure to "nitrite" whichever cation it may be associated with.

In addition, in 1988, the US EPA, Office of Pesticides and Toxic Substances issued a Notice to producers, Formulators, Distributors and Registrants regarding quaternary ammonium compounds with regard to "Clustering" of such quaternary ammonium compounds.

Prior to this, EPA had required each quat compound to be individually coded and registered as a new chemical, even when the chemical structure of individual compounds differed only slightly in alkyl distribution and chain lengths. This procedure was continued with the new generations of quats having two, three, and four chains. As a result, EPA records showed that some 211 registered technical grade active ingredient products containing varying concentrations of quats, each coded separately on the basis of alkyl chain length and percentage carbon distribution within the chain. At this time, there are approximately eight to ten thousands (8-10,000) registered end-use formulations.

However, questions were raised regarding whether the EPA could cluster or group the quats and pick one or more representative members of each cluster to be used in toxicity studies, instead of requiring separate studies on each quat. These same questions were raised when the EPA issued its March 4, 1987 Data Call-In Notice requiring all registrants of antimicrobial active ingredients to submit subchronic and chronic toxicological data to support the continued registration of their products.

In response to these questions, EPA solicited information from industry, the public, academia, industry cooperative work groups, the state of California, and Canada. EPA then reviewed all of the assembled information along with the chemical structure of most of the quats. Based on the results of this review, EPA developed the following four groupings of currently registered quat compounds:

Group I. The alkyl or hydroxyalkyl (straight chain) substituted Quats
Group II. The non-halogenated benzyl substituted Quats (includes hydroxybenzyl, ethylbenzyl, hydroxyethybenzyl, napthylmethyl, dodecylbenzyl, and alkyl benzyl)
Group III. The di-and tri-chlorobenzyl substituted
Group IV. Quats with unusual substituents (charged heterocyclic ammonium compounds).

Fundamental to this discussion EPA determined that "X-" in all of these structures would be attributed to "any anionic species". Therefore, this would mean in terms of toxicological evaluation the coutner anion in such quaternary ammonium compounds could be regarded as; e.g halogen (Cl-, Br-, I-,), saccharinate or cyclohexylsulphamate. It is therefore suggested here that nitrite (NO2-) could also be regarded as a pertinent anion.

Since the US EPA deem that such a clustering of structures for toxicological evaluation is well founded and that the counter anion could be regarded as "any anionic species" then it would seem that to consider available toxicological data on sodium nitrite, in order to evaluate any health effects that may be incurred from exposure to the nitrite anion (NO2-), is justifiable.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: Guideline not given

Deviations:

not specified

GLP compliance:

not specified

Species:

mouse

Strain:

not specified

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

Male and female mice (10 animals/sex/dose) were dosed by gavage with 100, 150, 200, 250 and 300 mg/kg of a 0.5 – 2% aqueous solution of sodium nitrite.

Doses:

100, 150, 200, 250 and 300 mg/kg of a 0.5 – 2% aqueous solution of sodium nitrite.

No. of animals per sex per dose:

10 animals/sex/dose

Control animals:

not specified

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

214 mg/kg bw

Based on:

test mat.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

216 mg/kg bw

Based on:

test mat.

Mortality:

All animals that died were found to have methaemoglobin in their blood, although the levels are not reported. Mice receiving the larger doses died within a few minutes and all other mice (except one) that died did so within 24 hours

Clinical signs:

other: All animals that died were found to have methaemoglobin in their blood, although the levels are not reported.

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

Sodium nitrite was tested for acute oral toxicity and reported in a publication entitled : "On the Toxicity of Hydroxylamine"; (H. Riemann, Acta. Pharmacol. 6, 285-292, 1950). The LD50 value was 214 mg/kg for males and 216 mg/kg for females.

Executive summary:

The acute oral toxicity of sodium nitrite was investigated and reported in a publication entitled "On the Toxicity of Hydroxylamine", (H. Riemann, Acta. Pharmacol. 6, 285-292, 1950), as a primary source. This publication is also referenced in the Screening Information Dataset (SIDS) Initial Assessment Report (2005) for sodium nitrite as a secondary source.

The study was assigned a reliability score of 2 in accordance with the criteria for assessing data quality set forth by Klimisch et al. (1997). The SIDS report regards this publication as a reliable source.

In this study male and female mice (10 animals/sex/dose) were dosed by gavage with 100, 150, 200, 250 and 300 mg/kg of a 0.5 – 2% aqueous solution of sodium nitrite. All animals that died were found to have methaemoglobin in their blood, although the levels are not reported. Mice receiving the larger doses died within a few minutes and all other mice (except one) that died did so within 24 hours. The LD50 value was 214 mg/kg for males and 216 mg/kg for females.

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1969

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: basic information given

Justification for type of information:

Since in the stomach the gastic juice is acidic, made up of acids and enzymes, it is suggested that in this evironment it is highly unlikely that the quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites substance (s) will remain ionically bound to each other and thus are prone to dissociation in which case the released cation(s) will associate with other anions and the released anion will associate with cations. Thererfore, it is suggested that read-across data from sodium nitrite is considered appropriate in order to arrive at a conclusion in terms of any health effects that may be incurred from exposure to "nitrite" whichever cation it may be associated with.

In addition, in 1988, the US EPA, Office of Pesticides and Toxic Substances issued a Notice to producers, Formulators, Distributors and Registrants regarding quaternary ammonium compounds with regard to "Clustering" of such quaternary ammonium compounds.

Prior to this, EPA had required each quat compound to be individually coded and registered as a new chemical, even when the chemical structure of individual compounds differed only slightly in alkyl distribution and chain lengths. This procedure was continued with the new generations of quats having two, three, and four chains. As a result, EPA records showed that some 211 registered technical grade active ingredient products containing varying concentrations of quats, each coded separately on the basis of alkyl chain length and percentage carbon distribution within the chain. At this time, there are approximately eight to ten thousands (8-10,000) registered end-use formulations.

However, questions were raised regarding whether the EPA could cluster or group the quats and pick one or more representative members of each cluster to be used in toxicity studies, instead of requiring separate studies on each quat. These same questions were raised when the EPA issued its March 4, 1987 Data Call-In Notice requiring all registrants of antimicrobial active ingredients to submit subchronic and chronic toxicological data to support the continued registration of their products.

In response to these questions, EPA solicited information from industry, the public, academia, industry cooperative work groups, the state of California, and Canada. EPA then reviewed all of the assembled information along with the chemical structure of most of the quats. Based on the results of this review, EPA developed the following four groupings of currently registered quat compounds:

Group I. The alkyl or hydroxyalkyl (straight chain) substituted Quats
Group II. The non-halogenated benzyl substituted Quats (includes hydroxybenzyl, ethylbenzyl, hydroxyethybenzyl, napthylmethyl, dodecylbenzyl, and alkyl benzyl)
Group III. The di-and tri-chlorobenzyl substituted
Group IV. Quats with unusual substituents (charged heterocyclic ammonium compounds).

Fundamental to this discussion EPA determined that "X-" in all of these structures would be attributed to "any anionic species". Therefore, this would mean in terms of toxicological evaluation the coutner anion in such quaternary ammonium compounds could be regarded as; e.g halogen (Cl-, Br-, I-,), saccharinate or cyclohexylsulphamate. It is therefore suggested here that nitrite (NO2-) could also be regarded as a pertinent anion.

Since the US EPA deem that such a clustering of structures for toxicological evaluation is well founded and that the counter anion could be regarded as "any anionic species" then it would seem that to consider available toxicological data on sodium nitrite, in order to evaluate any health effects that may be incurred from exposure to the nitrite anion (NO2-), is justifiable.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

no guideline available

Principles of method if other than guideline:

According to Thompson W.R., Bacteriol. Rev. 11:115 using the Tables of Weil C.S. Biometrics 8:249, 1952

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

Constituent

Species:

rat

Strain:

Wistar

Sex:

male

Details on test animals or test system and environmental conditions:

Four to five weeks of age and 90 to 120 grams in weight which have been reared in the colony and maintained from time of weaning on Rockland rat diet, complete.

Route of administration:

other: gastric intubation

Vehicle:

not specified

Details on oral exposure:

Whenever possible, the chemical is administered undiluted. When a lesser concentration is necessary, solution in water or corn oil or suspension in semi-solid agar are the preferred expedients. Occasionally, a 1% solution of TERGITOL Penetrant 7 (essentially an aqueous solution of 25% sodium 3,9 diethyl-6-tridecanol sulfate) has been used as a dispersing agent.

Doses:

180 mg/kg; intubated as 0.010 gm/ml concentration

Control animals:

not specified

Details on study design:

The dosages are arranged in a logarithmic series differing by a factor of two.Occasionally, a 1% solution of TERGITOL Penetrant 7 (essentially an aqueous solution of 25% sodium 3,9 diethyl-6-tridecanol sulfate) has been used as a dispersing agent. Based upon mortalities during a 14-day observation period, the most probable LD50 value and its fiducial range are estimated by the method of Thompson using the Tables of Weil. The figures in parentheses show limits of + 1.96 standard deviations while the absence of parentheses indicates that no range is calculable because no dosage resulted in fractional mortality.

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

180 mg/kg bw

Mortality:

No data

Clinical signs:

other: No data

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

Sodium nitrite was tested for acute oral toxicity and reported in a publication entitled : "Range-Finding Toxicity Data: List VII", (Smyth, H.F., Carpenter, C.P., Weil, C.S., Pozzani, U., Striegel, J.A., Nycum, J.S., Am. Ind. Hyg. Assoc. J. 30, 470-476, 1969). The LD50 was determined to be 180 mg/kg bw.

Executive summary:

The acute oral toxicity of sodium nitrite was investigated and reported in a publication entitled " "Range-Finding Toxicity Data: List VII" (Smyth, H.F., Carpenter, C.P., Weil, C.S., Pozzani, U., Striegel, J.A., Nycum, J.S., Am. Ind. Hyg. Assoc. J. 30, 470-476, 1969), as the primary source. This publication is also referenced in disseminated REACH registration dossier for sodium nitrite as a secondary source.

The study was assigned a reliability score of 2 in accordance with the criteria for assessing data quality set forth by Klimisch et al. (1997).

Under the conditions of the study the LD50 was determined to be 180 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

699 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:

supporting study

Study period:

1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Read across justification is presented from the structurally analogous quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides to the quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites.

In the stomach the gastic juice is acidic, made up of acids and enzymes. In such an evironment it is highly unlikely that the quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites substance (s) will remain ionically bound to each other and thus are prone to dissociation in which case the released cation(s) will associate with other anions and the released anion will associate with cations. Thererfore, it is suggested read-across that data from the corresponding quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides is considered approriate in that such substances are likely to dissociate in a similar manner.

Furthermore, in 1988, the US EPA, Office of Pesticides and Toxic Substances issued a Notice to producers, Formulators, Distributors and Registrants regarding quaternary ammonium compounds with regard to "Clustering" of such quaternary ammonium compounds.

Prior to this, EPA had required each quat compound to be individually coded and registered as a new chemical, even when the chemical structure of individual compounds differed only slightly in alkyl distribution and chain lengths. This procedure was continued with the new generations of quats having two, three, and four chains. As a result, EPA records showed that some 211 registered technical grade active ingredient products containing varying concentrations of Quats, each coded separately on the basis of alkyl chain length and percentage carbon distribution within the chain. At this time, there are approximately eight to ten thousands (8-10,000) registered end-use formulations.

However, questions were raised regarding whether the EPA could cluster or group the quats and pick one or more representative members of each cluster to be used in toxicity studies, instead of requiring separate studies on each quat. These same questions were raised when the EPA issued its March 4, 1987 Data Call-In Notice requiring all registrants of antimicrobial active ingredients to submit subchronic and chronic toxicological data to support the continued registration of their products.

In response to these questions, EPA·solicited information from industry, the public, academia, industry cooperative work groups, the state of California, and Canada. EPA then reviewed all of the assembled information along with the chemical structure of most of the quats. Based on the results of this review, EPA developed the following four groupings of currently registered quat compounds:

Group I. The alkyl or hydroxyalkyl (straight chain) substituted Quats
Group II. The non-halogenated benzyl substituted Quats (includes hydroxybenzyl, ethylbenzyl, hydroxyethybenzyl, napthylmethyl, dodecylbenzyl, and alkyl benzyl)
Group III. The di-and tri-chlorobenzyl substituted
Group IV. Quats with unusual substituents (charged heterocyclic ammonium compounds).

Fundamental to this discussion EPA determined that "X-" in all of these structures would be attributed to "any anionic species". Therefore, this would mean in terms of toxicological evaluation the coutner anion in such quaternary ammonium compounds could be regarded as; e.g halogen (Cl-, Br-, I-,), saccharinate or cyclohexylsulphamate. It is therefore suggested here that nitrite (NO2-) could also be regarded as a pertinent anion.

Since the US EPA deem that such a clustering of structures for toxicological evaluation is well founded then it would seem that to consider read-across data from quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides to the closely structurally analogous quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites to be equally justifiable.

Furthermore, in certain organic solvents it has been reported that the exchange constants between nitrite and chloride in quaternary ammonium salts (QAS) are approximately equal. [Zhurnal Analiticheskoi Khimii, 2010, Vol. 65, No. 6, pp. 579–584. (E.M. Rakhman’ko, M.S. Markovskaya, L.S. Stanishevskii, Yu.S. Zubenko, A.R. Tsyganov)]

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

EPA OPP 81-3 (Acute inhalation toxicity)

Deviations:

not specified

GLP compliance:

yes

Test type:

other: Standard acute method

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): Armoblen 400
- Composition of test material, percentage of components:- cocobenzyldimethylammoniumchloride: 40% w/v, dicocodimethylammoniumchloride: 37.5% w/v, total amount of quarternary ammonium compounds:77.3% w/v, water: 7.7%
- Purity test date: 21 December 1989
- Batch No.: RCD/VRE-55
- Expiration date of the lot/batch: December 1990
- Storage condition of test material: In dark at room temperature

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK Ltd., Margate, UK
- Weight at study initiation: ca. 200 g on the day of exposure
- Housing: 5/sex in polypropylene cages with detachable wire mesh tops and floors
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 d


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-24
- Humidity (%): 35-65


IN-LIFE DATES: From: 21 February 1990 To: 30 April 1990

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

other: Unchanged (no vehicle)

Remark on MMAD/GSD:

- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):
0.34 mg/L : MMAD 1.9 µm, gsd 3.5
0.17 mg/L : MMAD 1.1 µm, gsd 2.7
0.24 mg/L : MMAD 0.8 µm, gsd 0.8

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Perspex whole body chamber (square section with pyramidal top)
- Exposure chamber volume: ca. 120 L
- Method of holding animals in test chamber: Wire mesh partitions to provide 10 separate animal compartments
- Source of air: Filtered and oil-free compressed air
- Method of conditioning air: Dried
- System of generating particulates/aerosols: Atomiser
- Method of particle size determination: Cascade impaction (Andersen mini-sampler & Marple cascade impactor (model 296))
- Treatment of exhaust air: Passage through a collection filter
- Temperature, humidity, pressure in air chamber: Temperature measured at 30-min intervals (22-23 ºC ), relative humidity not measured (reason: aqueous solution). However, as dried air was used and the test material contained only 7.7 % water, relative humidity could have been measured. Pressure in air chamber: not indicated. However, as the whole body chamber was placed in a hood, this is not as important.

TEST ATMOSPHERE
- Brief description of analytical method used:
Five air samples (5 L for Groups 2 and 4 (0.34 and 0.24 mg/L), 10 L for Group 3 (0.17 mg/L)) were taken from the chamber during each exposure and the collected material was analysed to determine the concentration of Armoblen 400 in the chamber air. Each air sample was withdrawn, at 4 L/min, through a weighed glass fibre filter (Whatman GF/A) mounted in an open face filter holder. The volume of the air sample was measured with a wet-type gas meter. Two further air samples were taken using an Andersen mini-sampler or a series 290 Marple cascade impactor (Model 296), and the collected material was weighed to determine the particle size distribution of Armoblen 400. The samples were taken at approximately 1.5 and 3.5 h from the start of exposure. The filters from the open face sampler were transferred to extraction columns and compacted with a glass rod. The Armoblen 400 was eluted with five 2 mL portions of methanol into a 20 mL volumetric flask and diluted to volume with methanol.
The filters from the Andersen and Marple samplers were similarly treated to give a final volume of 5 mL. The stages of the Andersen and Marple samplers were washed off with small amounts of methanol into 5 mL volumetric flasks. The extracts were diluted with mobile phase to obtain solutions for HPLC-analysis with expected maximum concentrations of Armoblen 400 of 150 pg/mL.

- Samples taken from breathing zone: Taken from the whole body chamber.

TEST ATMOSPHERE (if not tabulated)
-Concentrations:
0.34 mg/L (± 6%); nominal: 2.21 mg/L
0.17 mg/L (± 13%); nominal: 0.52 mg/L
0.24 mg/L (± 17%); nominal: 0.88 mg/L

- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):
0.34 mg/L : MMAD 1.9 µm, gsd 3.5
0.17 mg/L : MMAD 1.1 µm, gsd 2.7
0.24 mg/L : MMAD 0.8 µm, gsd 0.8

Analytical verification of test atmosphere concentrations:

yes

Remarks:

HPLC

Duration of exposure:

ca. 4 h

Concentrations:

0, 0.17, 0.24 and 0.34 mg/L

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 21 d
- Frequency of observations and weighing: Observations continuously during exposure and at least twice daily thereafter; body weight daily
- Food and water intake: Daily
- Necropsy of survivors performed: Yes
- Other examinations performed: Lung weight, histopathology of lungs, liver and kidneys

Statistics:

LC50 determination by log probit method of Miller LC and Tainter ML, Proc Soc Exp Bio Med 57 (2), 1944: 261-264

Preliminary study:

Not applicable

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

0.22 mg/L air (analytical)

Based on:

test mat.

95% CL:

> 0.17 - < 0.27

Exp. duration:

4 h

Key result

Sex:

female

Dose descriptor:

LC50

Effect level:

0.28 mg/L air (analytical)

Based on:

test mat.

95% CL:

> 0.21 - < 0.35

Exp. duration:

4 h

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

0.25 mg/L air (analytical)

Based on:

test mat.

95% CL:

> 0.22 - < 0.28

Exp. duration:

4 h

Mortality:

Control group: 0/10
0.17 mg/L: 1 male (1/10)
0.24 mg/L: 3 males and 1 female (4/10)
0.34 mg/L: 5 males and 4 females (9/10)

Clinical signs:

other: The signs seen during exposure were considered to be consistent with inhalation of an irritant aerosol. Closing or partial closing of the eyes and exaggerated respiratory movement were seen in all rats exposed to test material. Additional signs observed i

Body weight:

There were moderate to marked decreases of bodyweight or reductions in the rate of bodyweight gain for up to 8 d in male rats and for up to 14 d in female rats following exposure at 0.17 mg/L or 0.24 mg/L. Subsequently weight gain for rats that survived exposure to test material was similar to that of the control rats.

Gross pathology:

The findings for rats that died as a result of exposure to test material were typified by congestion of the lungs, fluid in the tracheae and gas-filled stomachs. Macroscopic abnormalities in a proportion of rats that survived exposure to test material were a swollen appearance of the lungs and gas-filled stomachs and intestines.

Other findings:

The food and water consumption for the rat that survived exposure at 0.34 mg/L was variable and reduced. Food consumption was reduced for up to 12 d following exposure to Armoblen 400 at concentrations of 0.24 or 0.17 mg/L. The water consumption for these groups was reduced for up to 14 d following exposure. The lung weight to bodyweight ratio was increased, due to a high lung weight, for most rats that died as a result of exposure to test material.

Histopathology
Group 2 (0.34 mg/L)
Decedents
Treatment-related changes were seen in the 5 male and 4 female decedents. The distribution of these lesions was as follows: focal alveolar wall necrosis in 3 males; diffuse congestion in 3 males and 4 females; eosinophilic material in alveoli in 5 males and 4 females; alveolitis in 2 males and 4 females; focal alveolar oedema in 1 male; perivascular oedema in 4 males.
Survivors
Treatment-related changes were seen in the single female rat surviving to the end of the observation period. These were as follows: focal alveolitis; focal bronchiolitis; prominent bronchiolar goblet cells.

Group 3 (0.17 mg/L)
Decedents
Treatment-related changes were seen in the single decedent male. These were as follows: diffuse congestion; eosinophilic material in alveoli; alveolitis; focal alveolar oedema.
Survivors
Treatment-related changes were seen in one of the 4 males and in one of the 5 females surviving to the end of the observation period. The distribution of these lesions was as follows: focal bronchiolitis in 1 male; prominent bronchiolar goblet cells in 1 male; foreign body giant cells in 1 male; focal alveolar haemorrhage in 1 female. A focus of emphysema was also seen in one surviving female. The significance of this finding in a single animal is unclear, but possibility that it is related to treatment cannot be excluded. No abnormalities were detected in 3 males and 3 females surviving to the end of the observation period.

Group 4 (0.24 mg/L)
Decedents
Treatment-related changes were seen in the 3 male decedents and 1 female decedent. The distribution of these lesions was as follows: diffuse or focalcongestion in 2 males and 1 female; eosinophilic material in alveoli in 2 males and 1 female; alveolitis in 1 male and 1 female; focal alveolar oedema in 1 male; focal alveolar haemorrhage in 1 female; perivascular oedema in 1 female.
Survivors
Treatment-related change was seen in one of the two males and one of the 4 females surviving to the end of the observation period. This lesion was: foreign body giant cells. No abnormalities were detected in 1 male and 3 females surviving to the end of the observation period.

Interpretation of results:

Category 2 based on GHS criteria

Conclusions:

Under the test conditions, the acute 4 h LC50 of the test material (containing cocobenzyldimethylammoniumchloride - 40% w/v, dicocodimethylammoniumchloride - 37.5 % w/v and water - 7.7 %) was found to be 0.25 mg/L (0.22 -0.28 mg/L) and it is classified as Category 2 according to CLP Regulation (EC 1272/2008).

Executive summary:

The acute inhalation toxicity of the test substance (containing cocobenzyldimethylammoniumchloride - 40% w/v, dicocodimethylammoniumchloride - 37.5 % w/v and water - 7.7 %) was investigated in a syudy conducted according to OECD guideline 403 and EPA-Guideline 81 -3 in compliance with GLP.

The study was assigned a reliability score of 1 in accordance with the criteria for assessing data quality set forth by Klimisch et al. (1997).

Four groups of ten rats each (five males and five females) were given a single, 4 h whole body exposure at concentration levels of 0, 0.17, 0.24 and 0.34 mg/L. The animals were observed for 21 d after the day of exposure and were then killed for gross and histopathological examination of the lungs. Body weight, food and water intake and lung weight were also determined.

There were no deaths in the control group; one animal (male) died at 0.17 mg/L, four animals died at 0.24 mg/L (3 males, 1 female), and nine animals died at 0.34 mg/L (5 males, 4 females). Clinical signs of toxicity noted were (partial) closing of the eyes and exaggerated respiratory movement during exposure in all test groups and gasping and wetness around the mouth during exposure at 0.34 mg/L. Clinical signs were noted in survivors throughout the 21 d observation period. Decrease of body weight, reduced body weight gain and reduced food and water intake was generally seen up to 14 d.

Abnormalities noted at necropsy in survivors were increased relative lung weight, swollen appearance of the lungs and gas-filled stomach and intestines. Animals that died showed congestion of the lungs, fluid in the trachea and gas-filled stomachs. Histopathological lung changes in survivors generally consisted of focal alveolitis and bronchiolitis; changes in deceased animals generally consisted of focal alveolar wall necrosis, diffuse congestion, focal alveolar wall oedema and focal alveolar wall haemorrhage.

Under the test conditions, the acute 4 h LC50 of the test material (containing cocobenzyldimethylammoniumchloride- 40% w/v, dicocodimethylammoniumchloride-37.5 % w/v and water 7.7 %) was found to be 0.25 mg/L (0.22 -0.28 mg/L) and it is classified as Category 2 according to CLP Regulation (EC 1272/2008).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

0 mg/m³ air

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

29 May, 1996 - 12 June, 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Read across justification is presented from the structurally analogous substance, didecyldimethylammonium chloride to quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites.

In 1988, the US EPA, Office of Pesticides and Toxic Substances issued a Notice to producers, Formulators, Distributors and Registrants regarding quaternary ammonium compounds with regard to "Clustering" of such quaternary ammonium compounds.

Prior to this, EPA had required each quat compound to be individually coded and registered as a new chemical, even when the chemical structure of individual compounds differed only slightly in alkyl distribution and chain lengths. This procedure was continued with the new generations of quats having two, three, and four chains. As a result, EPA records showed that some 211 registered technical grade active ingredient products containing varying concentrations of Quats, each coded separately on the basis of alkyl chain length and percentage carbon distribution within the chain. At this time, there are approximately eight to ten thousands (8-10,000) registered end-use formulations.

However, questions were raised regarding whether the EPA could cluster or group the quats and pick one or more representative members of each cluster to be used in toxicity studies, instead of requiring separate studies on each quat. These same questions were raised when the EPA issued its March 4, 1987 Data Call-In Notice requiring all registrants of antimicrobial active ingredients to submit subchronic and chronic toxicological data to support the continued registration of their products.

In response to these questions, EPA·solicited information from industry, the public, academia, industry cooperative work groups, the state of California, and Canada. EPA then reviewed all of the assembled information along with the chemical structure of most of the quats. Based on the results of this review, EPA developed the following four groupings of currently registered quat compounds:

Group I. The alkyl or hydroxyalkyl (straight chain) substituted Quats
Group II. The non-halogenated benzyl substituted Quats (includes hydroxybenzyl, ethylbenzyl, hydroxyethybenzyl, napthylmethyl, dodecylbenzyl, and alkyl benzyl)
Group III. The di-and tri-chlorobenzyl substituted
Group IV. Quats with unusual substituents (charged heterocyclic ammonium compounds).

Fundamental to this discussion EPA determined that "X-" in all of these structures would be attributed to "any anionic species". Therefore, this would mean in terms of toxicological evaluation the coutner anion in such quaternary ammonium compounds could be regarded as; e.g halogen (Cl-, Br-, I-,), saccharinate or cyclohexylsulphamate. It is therefore suggested here that nitrite (NO2-) could also be regarded as a pertinent anion.

Since the US EPA deem that such a clustering of structures for toxicological evaluation is well founded then it would seem that to consider read-across data from quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides to the closely structurally analogous quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites to be equally justifiable.

Furthermore, in certain organic solvents it has been reported that the exchange constants between nitrite and chloride in quaternary ammonium salts (QAS) are approximately equal. [Zhurnal Analiticheskoi Khimii, 2010, Vol. 65, No. 6, pp. 579–584. (E.M. Rakhman’ko, M.S. Markovskaya, L.S. Stanishevskii, Yu.S. Zubenko, A.R. Tsyganov)]

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

The test substance contains ca. 50% didecyldimethylammonium chloride (CAS no.: 7173-51-5) and 20% isopropanol (CAS no.: 67-63-0) in water.

Species:

rat

Strain:

Wistar

Remarks:

Wistar strain Crl:(WI) BR (outbred, SPF-quality)

Sex:

male/female

Details on test animals or test system and environmental conditions:

Species: Rat
Strain: Wistar strain Crl:(WI) BR (outbred, SPF-quality)
Source: Charles River, Sulzfeld, Germany.
Sex: Males and females
Age/weight at study initiation: Approx. 9 weeks, 373 g (mean males) and 240 g (mean females)
Number of animals per group: 5 males and 5 females
Control animals: No

Vehicle:

water

Details on dermal exposure:

Postexposure period: 15 days
Type: Dermal
Concentration: 2000 mg/kg bw for 24 hours (dose volume: 10 ml/kg in distilled water)
Vehicle: Distilled water
Concentration in vehicle: 200 mg/ml (20%)
Total volume applied: 10 ml/kg
Controls: No

Doses:

Limit test at 2000 mg/kg bw.

No. of animals per sex per dose:

10

Control animals:

no

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 1 000 mg/kg bw

Based on:

act. ingr.

Clinical signs:

other: Lethargy was noted in all animals, between days 2 and 4. Hunched posture was observed in four females between days 2 and 6. Skin effects in the treated area: Swelling, necrosis and hardening of the back, scabs and brown skin on the back were noted in all

Gross pathology:

No abnormalities were found at macroscopic post mortem examination Of the animals.

Other findings:

At removal of the bandages (day 2) it was noticed that the bandages of two Females (number 9 and 10) had shifted caudally.
The clinical signs shown by these animals were not significantly different compared to the other females. The exposure to the test
substance was therefore considered sufficient.

No mortality occurred. Effects noted were lethargy in all animals between day 2 and 4 and skin effects which consisted of swelling, redness, erythema and necrosis of the skin. The majority of the skin effects persisted until the end of the observation time. No abnormalities were found at macroscopic post mortem examination.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The acute dermal LD50 of the test substance in rats was determined to be >2000 mg/kg bw (i.e. >1000 mg a.i./kg bw).

Executive summary:

A study performed was performed according to GLP and OECD 402 and EU B.3 “Acute Dermal Toxicity” to investigate the dermal toxicity of the test item.

This study is assigned a reliability score of 1 in accordance with the criteria for assessing data quality set forth by Klimisch et al (1997).

Five male and five female rats received a dermal dose of 2000 mg/kg bw for 24 h (dose volume: 10 ml/kg in distilled water) under occlusive dressing for 24 h. One day before exposure (day -1) an area of approximately 5x7 cm on the back of the animal was clipped.
24 h, after which dressings were removed and residual test substance removed using a tissue moistened with tap water.

Animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed after terminal sacrifice on day 15.

No mortality occurred. Effects noted were lethargy in all animals between day 2 and 4 and skin effects which consisted of swelling, redness, erythema and necrosis of the skin. The majority of the skin effects persisted until the end of the observation time. No abnormalities were found at macroscopic post mortem examination. Effects are limited to local irritation/corrosion of the skin, without involvement of systemic toxicity.

The acute dermal LD50 of the test substance in rats were determined to be >2000 mg/kg bw (i.e. >1000 mg a.i./kg bw).

As quaternary ammonium compounds do not easily pass biological membranes, dermal absorption of these compounds is very limited. The dermal toxicity of aqueous DDAC solutions is related to its corrosivety and therefore more related to the concentration of the administered solution than of the actual amount in mg/kg. Due to the direct corrosive effect, there is danger of irreversible damage to the skin upon exposure to the undiluted solution. Further toxicity is secondary to the local tissue damage, rather than the result of percutaneously absorbed material. Some reviews mention comparable dermal LD₅₀data in rat from literature which is in the range 2000 – 3000 mg/kg bw.

Toxicity is related to concentration dependent cytotoxicity, with a lack of specific systemic toxicity. The toxicity (and efficacy as based on same mechanism of action) show a dependence on chain length, with an optimum at C₁₀-C₁₂. Therefore this test using C₁₀-chainlength can be seen as worst case representative for the whole group of DDAC compounds between C₈and C₁₈.

Furthermore, additional tests for acute dermal toxicity are not ethical due to its corrosive effects and can thus not be performed.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 000 mg/kg bw