Caffeine

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1985-05-31 (day of dosing)

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: comparable to guideline study

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Reference 2

Reference Type:

other: addendum to study report

Title:

Unnamed

Report date:

2006

Reference 3

Reference Type:

other: addendum to study report

Title:

Unnamed

Report date:

2006

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Principles of method if other than guideline:

BASF test. In principle, the methods described in OECD guideline 401 were used.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Caffeine

EC Number:

200-362-1

EC Name:

Caffeine

Cas Number:

58-08-2

Molecular formula:

C8H10N4O2

IUPAC Name:

1,3,7-trimethyl-3,7-dihydro-1H-purine-2,6-dione

Details on test material:

- Name of test material (as cited in study report): Coffein (caffeine)
No further data.

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr. K. Thomae GmbH, D-7950 Biberach, Germany
- Weight at study initiation: mean weights: 179 - 199 g (males); 180 - 189 g (females)
- Fasting period before study: yes. The animals were given no food 16 hours before administration, but water was available ad libitum.
- Housing: 5 per cage, in stainless steel wire mesh cages
- Diet (ad libitum): Kliba Labordiät, Klingentalmühle, CH-4303 Kaiseraugst, Switzerland
- Water (ad libitum): tap water
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24 °C
- Humidity (%): 30 - 70 %
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: no data

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on oral exposure:

VEHICLE
0.5% aqueous carboxymethylcellulose
- Concentration in vehicle: 1.78 - 3.83 % (w/v), see table 1 below
- Amount of vehicle (if gavage): 10 ml/kg bw
- Justification for choice of vehicle: aqueous formulation corresponds to the physiological medium

MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg bw

Doses:

178, 261, 383 mg/kg bw

No. of animals per sex per dose:

5 males and 5 females per dose group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology
Group-wise documentation of clinical signs was performed over the 14-day observation period. The clinical signs and findings are reported in summary form.
Body weight was determined before the start of the study as it was needed for determination of the dose.

Statistics:

On the basis of the observed lethality, the LD50 was estimated or determined using a graphical evaluation of the dose-response curve on probability paper.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

367.7 mg/kg bw

Mortality:

In the high dose group, 3/5 males and 5/5 females died within 1 day after dosing. No other deaths were reported. See table 2 below.

Clinical signs:

other: Signs of toxicity comprised dyspnea, apathy, staggering, piloerection , and poor general state. The symptoms persisted up to day 7 post dose and were observed in all groups, regardless of sex and dose level.

Gross pathology:

General congestion was observed in male and female decedents. No abnormalities of the organs were observed in survivors sacrificed at the end of the observation period.

Any other information on results incl. tables

Table 2: mortality rates

Dose [mg/kg bw]		178	261	383
males
Number of animals		5	5	5
Dead animals after	1 hour 1 day 2 days 7 days 14 days	0 0 0 0 0	0 0 0 0 0	0 3 3 3 3
females
Number of animals		5	5	5
Dead animals after	1 hour 1 day 2 days 7 days 14 days	0 0 0 0 0	0 0 0 0 0	0 5 5 5 5

Table 3: Body weight data, mean body weight in [g]

Dose [mg/kg bw]		178	261	383
males
Beginning of the test		181	179	199
after	3 days 7 days 14 days	194 222 259	179 217 260	208 243 287
females
Beginning of the test		180	180	189
after	3 days 7 days 14 days	182 204 220	181 201 221	all animals died by day 1

LD50 determination oral actue toxicity in rats (Probit Analysis)

LD50 derived from observations (1985):

LD50 (males and females: >261 <383 mg/kg

LD50 (males): ca. 383 mg/kg

LD50 (females): >261 <383 mg/kg

Statistical estimation of LD50 (2006):

Due to the GHS-classification for this test substance, a detailed determination of the LD50 was necessary, because the statement given in the original study report of 1985 ("the LD50 is greater than 261 mg/kg and lower than 383 mg/kg") is not sufficient; classification limits are 300 mg/kg and 2000 mg/kg. Therefore, the dose-response curve was fitted via the Probit model (according to Finney DJ Probit analysis, Cambridge Univ Press, 3rd ed. 1971). Statistical analyses were performed using the SAS system.

The LD50 of males and females is estimated as 367.7 mg/kg.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Remarks:

Migrated information

Executive summary:

LD50: 367.7 mg/kg bw (males and females)

Groups of 5 male and 5 Wistar rats were administered the test substance by gavage at doses of 178, 261, and 383 mg/kg bw and were observed for 14 days. Eight out of 10 rats given 383 mg/kg bw died within the first day after dosing; no other deaths were reported. Signs of toxicity were observed in all groups and comprised dyspnea, apathy, staggering, piloerection, and poor general state. Body weight gain was unaffected. Pathology revealed general congestion in decedents and no abnormalities in survivors.