Vinyl neononanoate

Acute Toxicity: inhalation

Administrative data

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: Study was conducted according to an O.E.C.D. Testing Guideline following the GLP regulations.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Details on test material:

As per IUCLID5 Sections 1.1 -1.4.

Specific details on test material used for the study:

Product name: VeoVa 9
Product code: K3111
Product type: Vinyl ester
Substance formal name: Vinyl ester of neononanoic acid
Substance chemical family: Koch acid derivative
Synonyms: Vinyl neononanoate
CAS number: 54423-67-5
Physicai state: Liquid
Colour: Clear
Odour: Ester
Initial boiling point: 185°C
Final bolting point: 200°C
Vapour pressure: 1.2 kPa @ 68°C
Density: 890 kgm3 @ 20°C
Kinematic viscosity: 2.1 mmzs @ 20°C
Vapour density (air=1): >3
Flash point: 70°C (ASTM D93)
Auto-ignition temperature: 372°C
Soiubility in water: 8 kg.m3
n-octanoi/water partition
coefficient: >3 [ogPow (estimated)
Other properties: Molecular weight 184

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Animals were acquired from Charles River (UK) Margate, Kent and were 5-6 weks of age with a body weight range of 113-124 Grams. Animals were housed 5/sex in suspended polypropylene cages with detachable stainless tops and bottoms. The temperature was maintained at 22 c =/- 3 C and a relative humidity range og 30-70%. There were approximately 15-20 air exchanges per hr. a 12 hr light/dark cycle was maintained. Rat and Mouse (Modified) No. 1 Diet SQC Expanded supplied by Special Diets Services, Stepfield, Witham, Essex was available ad libitum. Domestic mains quality drinking water was supplied ad Libitum.

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose only

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

VeoVa 9 was tested in its original liquid form. The test atmosphere wasgenerated as a vapour.

The test atmosphere was generated using a vapourising system (as shown in Figure 1). This consisted of a test material reservoir which was placed in a water bath (ca 60°C) and through which compressed air was passed at a fixed rate throughout the duration of each exposure. The resultant vapour was then ducted into the exposure chamber. The different dose levels were achieved by varying the airflow through the test material reservoir then diluting, as appropriate, with clean airjust prior to introducing the vapour/air mixture into the exposure chamber. The dilutions employed were:

Group Air Via Reservoir Additional Air to Chamber

1 10 l.min^-1 0 |.min^-1
2 2 l.min^-1 8 l.min^-1
3 5 l.min^-1 5 l.min^-1

Filtered, oil-free compressed air for the production of the test atmosphere was supplied by Hydrovane compressors.

The exposure chamber was a modular flow past design, was cylindrical in cross section and had a volume of approximately 2.0 litres. An extract duct from the chamber was connected by way of a high efficiency filter to a metered vacuum system. The exposure chamber was located inside an extract cabinet for the protection of operators and the environment.

The exposure system was dynamic, incorporating a single pass of the freshly generated material. The vapour dispersed throughout the chamber and exited through the base to a filtered vacuum line.

Chamber airflow rates were monitored continuously using ticw meters and the values were recorded at 30 min intervals.

The inhalation exposure was conducted in a laboratory adjacent to the animals' holding room. Each animal was removed from its cage and examined for general health status. The ear number was checked, the animal weighed and then loaded into a tapered, polycarbonate restraint tube which fitted onto the exposure chamber and sealed by means of a push—fit through a rubber ‘O’ ring. All the animals were exposed on a single tier to eliminate any exposure variation. Only the animals’ snouts were exposed to the test atmosphere. The animals were not allowed access to food or water during the 4 h exposure period.

Chamber concentrations were optimised during preliminary procedures and measured at regular intervals during the exposure periods. The sampling
method used employed 2 glass impinger tubes in series. The input side of the sampling system was positioned and temporarily sealed in a port in the
exposure chamber at the animals’ breathing zone. Chamber air was drawn through the sampling system at a measured rate of approximately 1.0 imin^-1 via a gas meter and vacuum pump. The air flow during each sample was controlled by a flowmeter and timed for a suitable period. All samples were
submitted for chemical analyses (GC) using methodology supplied by the Sponsor and validated at Inveresk Research.

All animals were observed during the exposure for signs of any adverse reactions to treatment. On completion of the 4 h exposure period, the animals were removed from the chamber, unioaded from the restraint tubes, returned to their cages in the animal holding room and observed for clinical signs.

Each group of 5 male and 5 female rats was exposed to an atmosphere containing VeoVa 9. by the inhalation route via snout only exposure for a single 4 h period.

During each exposure period the temperature within the exposure chamber was measured by a mercury thermometer located at the animals’ breathing zone whilst the relative humidity was monitored using wet/dry bulb mercury thermometers. The chamber temperature and relative humidity were measured at 30 min intervals throughout the exposure period.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

by GC analysis

Duration of exposure:

4 h

Concentrations:

0.48-3.23 mg/l

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

Animals were exposed to vapours of vinyl neononanoate by nose-only inhalation for 4 hr. Animals were then observed for 1-2 hr post-dosing and then twice daily for clinical signs of toxicity. Body weights were taken on study days, 0, 2, 3, 4, 7, 10 and 14. At the end of the 14-day observation period a macroscopic post mortem was conducted on all surviving animals. The respiratory tract was subjected to a detailed macroscopic examination. Lung weights were taken during necrospy.

Statistics:

None conducted.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

other: mortality

Effect level:

ca. 3 230 mg/m³ air (nominal)

Exp. duration:

14 d

Mortality:

Two males and one female from group 1 ( high dose 3.23 mg/L) were killed in extremis approximately 1-2 h post dose. There were no deaths in groups 2 or 3.

Clinical signs:

other: Minimal clinical signs were observed at 0.48 and 1.43 mg/l. Animals treated at 3.23 mg/l showed hunched posture, prostrate posture, body tremors, subdued behavior and unsteady gait and exaggerated and violent body movements. Those rats which were killed i

Body weight:

No significant effects were recorded for body weight profiles throughout the observation period.

Gross pathology:

No sifnificant findings.

Other findings:

Lung weights and lung weight/body weight ratios were no impacted by exposure to vinyl neononanoate.

Applicant's summary and conclusion

Interpretation of results:

sligthly toxic

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

Approximately 30% mortality was observed at the high dose level of 3.23 mg vinyl neononanoate/L following 4 hr of nose-onlly exposure. Therefore the 4 hr LC50 value is > 3.23 mg/L (~ 430 ppm). Significant evidence of neurotoxicity based upon clinical signs was observed at this toxic dose level.

Executive summary:

Vinyl neononanoate was assessed for acute inhalation toxicity in an O.E.C.D. Testing Guideline study with GLP compliance by nose-only vapour exposure. The 4 hr LC50 value was determined to be > 3.23 mg/L (~ 430 ppm). Significant evidence of neurotoxicity based upon clinical signs was observed at this toxic dose level.