Phenol, dodecyl-, branched

Endpoint summary

Description of key information

Oral:
The test material was administered by gavage to 6 groups of 5 (mix of M & F) Sprague-Dawley albino rats at doses of 1260, 1580, 2000, 2510, 3160 and 3980 mg/kg. A 14-d observation period followed administration. Calculation of an LD50 was done according to the method of E.J. de Beer.
The calculated oral LD50 for dodecylphenol was 2100 mg/kg (95% confidence limits 1620-2730 mg/kg; slope 3.5). For the doses of 1260, 1580, 2000, 2510, 3160 and 3980 mg/kg, the number of deaths were 1, 2, 2, 4, 4 and 4, respectively, out of 5 animals per group. Clinical signs included weight loss (1 to 6 days in survivors), increasing weakness, diarrhea, collapse and death. Autopsy of decedents showed hemorrhagic lungs, areas of liver discoloration and gastrointestinal inflammation. Viscera of surviving animals appeared normal at sacrifice.
Dermal:
Three of six rabbits dosed at 15 grams per kilogram died within seven days. None of six animals dosed at 5 grams per kilogram died within a 14-day observation period. There was no incidence of gross pathology in survivors sacrificed 14 days after dosing.
The test material, when administered to rabbits, had an acute dermal LD50 of approximately 15,000 mg/kg. Dermal irritation was evident in all animals.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

2 100 mg/kg bw

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

15 000 mg/kg bw

Additional information

Oral:

In the key study for oral exposure (Randall & Robinson, 1978), no guideline was specified and limited information was available as the paper was a summary report, however the basic principles look similar to OECD Guideline 401. The study pre-dates GLP. A reliability rating of 2 according to the criteria of Klimisch, 1997. This was considered to be the key study as it provided the lowest LD50 and therefore would be the worst case scenario for classification purposes.

There are also 3 supporting studies for this endpoint:

- The Mürmann, 1984 study was not considered the key study as the LD50 was a higher value than the key study. Both studies indicate that the test material is not orally toxic. This study was not conducted to a recognised guideline, only limited information was presented and the information was obtained from the peer reviewed, 2006 OECD SIDS dossier due to the original report being unavailable. The study was considered to have a reliability rating of 2, according to the criteria of Klimisch, 1997.

The test material, when administered to male and female rats, had an acute oral LD50 of 2200 mg/kg.

- The Cavalli et al, 1968 study was not considered the key study as the LD50 value was not determined, therefore classification according to EU regulations could not be determined based on the results of this study.

This study was not conducted to a recognised guideline, only limited information was presented and only 2 dose groups were used. The study was considered to have a reliability rating of 2, according to the criteria of Klimisch, 1997.

Ten rats dosed at 5 grams per kilogram with the test material died within three days. None of the ten rats dosed at 0.5 grams per kilogram died within a 14-day observation period. There was no incidence of gross pathology in animals dying or in animals sacrificed at 14 days after dosing.

- The Costello & Gilman, 1982 study was not considered the key study as the LD50 value was not determined, therefore classification according to EU regulations could not be determined based on the results of this study.

The study was considered to have a reliability rating of 2, according to the criteria of Klimisch, 1997.

All of the animals appeared ruffled with oily coats and mild diarrhea after 3 hours. Within 24 hours the diarrhea was severe and persisted until death. Gross pathologic examination revealed nothing remarkable.

The LD50 is less than 5.0 gm/kg.

Dermal:

In the key study for dermal exposure (Cavalli et al, 1968) no guideline was specified and limited information was available as the paper was a summary report, however the basic principles look similar to OECD Guideline 402 (Acute Dermal Toxicity), however the study pre-dates both the OECD guideline and GLP. A reliability rating of 2 according to the criteria of Klimisch, 1997. This was considered to be the most reliable study as it provided an actual LD50 value.

There is also a supporting study for this endpoint:

- The Randall & Robinson study, 1978 was not considered the key study as the LD50 was a greater than value whereas the key study gave a more precise value. Both studies indicate that the test material is not dermally toxic. This study was not conducted to a recognised guideline and only limited information was presented. The study was considered to have a reliability rating of 2, according to the criteria of Klimisch, 1997.

The dermal LD50 was estimated to be greater than 2000 mg/kg.

Inhalation:

In accordance with column 2 of REACH annex VIII, it is considered justifiable to omit the acute toxicity: inhalation study. The substance only exists in liquid form and it will not be aerosolised in its normal use pattern. Futhermore, information on the substance's vapour pressure suggests that the substance is unlikely to be inhaled thus exposure to humans via the inhalation route is not considered likely.

Justification for classification or non-classification

Oral:

The key parameter chosen for acute toxicity for the oral route was greater than the criteria set out in Directive 67/548/EEC and also Regulation (EC) no 1272/2008, therefore classification for acute toxicity was not considered to be necessary.

Dermal:

The key parameter chosen for acute toxicity for the dermal route was greater than the criteria set out in Directive 67/548/EEC and also Regulation (EC) no 1272/2008, therefore classification for acute toxicity was not considered to be necessary.