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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
repeated dose toxicity: oral
Remarks:
other: read-across from several repeated dose toxicity studies, including chronic data
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The analogue CAS No. 128-37-0 (BHT) which shares the same functional group (alkylphenol) with the two main constituents of the substance Reaction mass of 2,6-di-tert-butylphenol and 2,4,6-tri-tert-butylphenol, also has comparable values for the relevant molecular properties. Therefore, the results obtained with the substance CAS No. 128 -37-0 can be used for the read-across approach.

Data source

Reference
Reference Type:
other: read-across
Title:
Unnamed
Year:
2010

Materials and methods

Principles of method if other than guideline:
Read-across approach from data on an analogue.
GLP compliance:
no

Test material

Constituent 1
Reference substance name:
2,6-di-tert-butyl-p-cresol
EC Number:
204-881-4
EC Name:
2,6-di-tert-butyl-p-cresol
Cas Number:
128-37-0
IUPAC Name:
2,6-di-tert-butyl-4-methylphenol
Details on test material:
- Molecular formula (if other than submission substance): C15H24O
- Molecular weight (if other than submission substance): 220.35
- Smiles notation (if other than submission substance): Cc1cc(c(O)c(c1)C(C)(C)C)C(C)(C)C
- InChl (if other than submission substance): InChI=1/C15H24O/c1-10-8-11(14(2,3)4)13(16)12(9-10)15(5,6)7/h8-9,16H,1-7H3
- Structural formula attached as image file (if other than submission substance): see Fig.

Results and discussion

Effect levels

Dose descriptor:
NOAEL
Effect level:
25 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

The analogue CAS No. 128-37-0 (BHT) which shares the same functional group (alkylphenol) with the two main constituents of the substance Reaction mass of 2,6-di-tert-butylphenol and 2,4,6-tri-tert-butylphenol, also has comparable values for the relevant molecular properties. Therefore, the results obtained with the substance CAS No. 128 -37-0 can be used for the read-across approach.

  

- a log Pow value which is 4.9 for the Reaction mass of 2,6-di-tert-butylphenol and 2,4,6-tri-tert-butylphenol and 5.2 for 2,6-di-tert-butyl-4-methylphenol (BHT) and

 

- a low water solubility which is 0.4 ± 0.3 mg/L at 20 ºC for the Reaction mass of 2,6-di-tert-butylphenol and 2,4,6-tri-tert-butylphenol and 0.4-0.6 mg/L at 20-25 ºC for 2,6-di-tert-butyl-4-methylphenol (BHT)

DATA MATRIX read- across (any other information on results, including tables)

CAS Number

 

Source chemical

128-37-0

Target chemical

 

CHEMICAL NAME

 

2,6-di-tert-butyl-4-methylphenol

Reaction mass of 2,6-di-tert-butylphenol and 2,4,6-tri-tert-butylphenol

PHYSICO-CHEMICAL DATA

 

Melting Point

Experimental results:

69.8 - 71 ºC

Experimental results:

-36.3 ºC to -28.2 ºC

 

Boiling Point

Experimental results:

265 ºC

Experimental results:

253.9 ºC

 

pKa

Experimental results:

pKa = 12.2

Experimental results:

Read-across from

2,6-di-tert-butylphenol:

pKa = 11.7 at 25 ºC

 

Read-across from

2,4,6-tri-tert-butylphenol:

pKa = 12.2 at 25 ºC

 

Partition Coefficient

(log Kow)

Experimental results:

Log Pow = 5.2

Experimental results:

log Pow = 4.9

 

Water solubility

 

Experimental results:

0.4 -0.6 mg/l at 20-25 ºC

 

Experimental results:

0.4 ± 0.3 mg/l at 20 ºC

Vapour pressure

Experimental data:

3.82 Pa at 24.85 ºC

Experimental results:

310 Pa at 20 ºC (2.33 mm Hg)

 

ENVIRONMENTAL FATE and PATHWAY

 

Aerobic Biodegradation

 

Estimated data:

Not readily biodegradable 

 

Experimental results:

Not readily biodegradable 

 

ENVIRONMENTAL TOXICITY

 

Acute Toxicity to Fish

Estimated data: ECOSAR

LC50 (96 h) = 0.2 mg/l

Experimental data: Key study:

LC50 (96 h)=0.31mg/L

Acute Toxicity to Aquatic Invertebrates

Experimental data:

EC50 (48 h) =0.48mg/L

Experimental data:

Key study in Daphnia magna:

48h-EC50= 0.4 mg/L

 

Toxicity to Aquatic algae and cyanobacteria

 

Estimated data: ECOSAR

EC50 (96 h) = 0.76 mg/L

Experimental data: 

Key study:

EC50 (72 H) = 3 mg/L

NOEC = 1.6 mg/L

 

 

MAMMALIAN TOXICITY

 

Acute Toxicity: Oral

Experimental data:

Key study: LD50 >6000 mg/kg bw (rats)

 

Experimental data:

Key study: LD50 = 2976 mg/kg bw (rats)

 

 

 

Acute Toxicity: Dermal

Experimental data:

Key study:

LD50 > 2000 mg/kg bw (rats)

 

Experimental data:

Key study:

LD50 > 2000 mg/kg bw (rats)

 

Skin and eye irritation.

Skin sensitisation.

Experimental data:

Key study:

Not a skin irritant.

 

Not an eye irritant.

 

Not a skin sensitizer.

 

Experimental data:

Key studies:

Not a skin irritant.

 

Eye damage Category 1

 

Not a skin sensitizer.

Repeated Dose Toxicity

Experimental results: Weight of evidence:

NOAEL from chronic study: 25 mg/kg bw/day

 

Experimental results: Weight of evidence: Read-across from 2,6-di-tert-butyl-4-methylphenol (BHT)

NOAEL from chronic study: 25 mg/kg bw/day

 

Genetic Toxicity in vitro

 

Gene mutation in bacteria

Experimental results: Weight of evidence:

Negative

Experimental results: Weight of evidence: Read-across from 2,6-di-tert-butyl-4-methylphenol (BHT)

Negative

 

Chromosomal aberrations

Experimental results: Weight of evidence:

Negative

Experimental results: Weight of evidence: Read-across from 2,6-di-tert-butyl-4-methylphenol (BHT)

Negative

 

Gene mutation in mammalian cells

Experimental results: Weight of evidence:

Negative

Experimental results: Weight of evidence: Read-across from 2,6-di-tert-butyl-4-methylphenol (BHT)

Negative

 

Genetic Toxicity in vivo

 

Experimental results: Weight of evidence:

Negative

Experimental results: Weight of evidence: Read-across from 2,6-di-tert-butyl-4-methylphenol (BHT)

Negative

 

Carcinogenicity

Experimental results: Weight of evidence:

Not classified as carcinogenic.

Experimental results: Weight of evidence: Read-across from 2,6-di-tert-butyl-4-methylphenol (BHT)

Not classified as carcinogenic.

 

Toxicity to reproduction

 

Experimental results: Weight of evidence:

 

Effects on fertility: 

The NOAEL was 25 mg/kg bw/day in the rat.

 

Developmental toxicity:

No data

 

Experimental results: Weight of evidence: Read-across from 2,6-di-tert-butyl-4-methylphenol (BHT)

Effects on fertility:

The NOAEL was 25 mg/kg bw/day in the rat.

 

Developmental toxicity: 

No data

 

Applicant's summary and conclusion

Conclusions:
Based on experimental data, the read-across approach is applied and the NOAEL is considered to be 25 mg/kg bw/day.
Executive summary:

The analogue CAS No. 128-37-0 (BHT) which shares the same functional group (alkylphenol) with the two main constituents of the substance Reaction mass of 2,6-di-tert-butylphenol and 2,4,6-tri-tert-butylphenol, also has comparable values for the relevant molecular properties. Therefore, the results obtained with the substance CAS No. 128 -37-0 can be used for the read-across approach.

Based on experimental data, the read-across approach is applied and the NOAEL is considered to be 25 mg/kg bw/day.