2-propanol and 2-butanol production, distn. residues

Endpoint summary

Description of key information

„2-propanol and 2-butanol production, distn. residue“ was found to be irritating to eyes in vivo (according to guideline OECD 405) and mildly irritating to eyes in vitro (according to guideline OECD 437).

The substance was found not being skin irritating (according to guideline EU B.46), but skin irritating based on the calculation method.

No irritating effects to the respiratory tract were observed in the 90 day repeated dose toxicity study.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Remarks:

other: newly approved in vitro method

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21. June 2010 - 05. July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study under GLP, according to international guidelines and with full documentation

Qualifier:

according to guideline

Guideline:

other: Commission Regulation (EC) No. 761/2009, Method B.46: “In Vitro Skin Irritation: Reconstructed human epidermis model test” adopted 23. July 2009

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD Guideline for the Testing of Chemicals, Draft Proposal for a New Guideline, In Vitro Skin Irritation: Reconstructed Human Epidermis (RhE) Test Method, Version 7.6, 9 September 2009

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: ECVAM international validation study on in vitro tests for acute skin irritation: Report on the validity of the EPISKIN and EpiDerm assays and on the Skin Integrity Function Test (Altern Lab Anim. 2007 Dec; 35 (6): 559-601)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Protocol for IN VITRO EpiDermTM SKIN IRRITATION TEST (EPI-200-SIT), Rev. 3/23/2009, MatTek Corporation, Ashland, MA 01721, USA

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Details on animal used as source of test system:

human-derived epidermal keratinocytes (EPI-200 tissues)

Justification for test system used:

OECD approved and validated test system, suitable to replace in vivo studies

Vehicle:

unchanged (no vehicle)

Details on test system:

The EpiDermTM tissue consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multi-layered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo. The EpiDermTM tissues are cultured on specially prepared cell cultures inserts.
Origin: Epi-200 tissues were procured from MatTek Corporation in Ashland, USA. Day of delivery: 1. July 2010 batch: 13657
pre-incubation of tissues at 37 °C and 5% CO2 for one hour; thereafter with fresh assay medium (0.9 mL) at 37 °C and 5% CO2 for 18 hours

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

Applied volume: 30 µL of test item

Duration of treatment / exposure:

35 - 60 minutes in incubator and then 24 hour incubation

Duration of post-treatment incubation (if applicable):

18 ±2 hours

Number of replicates:

One plate (three tissues) as negative control, one plate (three tissues) as positive control, one plate was used for the test item

Type of coverage:

other: nylon mesh

Amount / concentration applied:

See "Any other information on materials and methods incl. tables".

Duration of treatment / exposure:

See "Any other information on materials and methods incl. tables".

Observation period:

See "Any other information on materials and methods incl. tables".

Number of animals:

Not applicable

Irritation / corrosion parameter:

% tissue viability

Remarks:

Formazon production

Run / experiment:

mean of three tissues

Value:

56.7

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Table 1: Absorption values for negative control, test item and positive control (mean of 2 measurements, blank value substracted)

Designation	Negative Control	Test Item	Positive Control
Mean – blank (Tissue 1)	2.389	1.348	0.171
Mean – blank (Tissue 2)	2.244	1.240	0.182
Mean – blank (Tissue 3)	2.129	1.244	0.177
Mean of the three Tissues	2.254	1.277	0.177
Relative Standard Deviation of the three tissues	5.8%	4.8%	3.1%

Table 2: % Formazan production for the test item and positive control

Designation	Test Item	Positive Control
% Formazan production (Tissue 1)	59.8%	7.6%
% Formazan production (Tissue 2)	55.0%	8.1%
% Formazan production (Tissue 3)	55.2%	7.9%
% Formazan production Mean	56.7%	7.8%

Assessment

The relative absorbance values were reduced to 56.7% after the treatment. This value is above the threshold for irritation (50%). Therefore, the test item is considered as not irritant.

Interpretation of results:

GHS criteria not met

Conclusions:

The test item is considered not irritant. After the treatment, the relative absorbance values were decreased to 56.7%. This value is above the threshold for irritation (50%).
The optical density of the negative control was well within the required acceptability criterion of 1.0 < mean OD < 2.5. The positive control induced a decrease in the relative absorbance as compared to the negative control to 7.8 % (required: <= 20%) thus ensuring the validity of the test system. Variation within replicates was within the accepted range for negative control, positive control and test item. For these reasons, the result of the test is considered valid.

Executive summary:

The skin irritation potential of „2-propanol and 2-butanol production, distn. residue“ in theHuman Skin Model Test was determined following EU-Method B.46. One valid experiment under GLP was performed. Three tissues of the human skin model EpiDerm(TM) were treated with „2-propanol and 2-butanol production, distn. residue“ for 60 minutes.

30 µL of the liquid test item (using a nylon mesh) were applied to each tissue and spread to match the tissue size. DPBS-buffer was used as negative control, 5% SDS-solution was used as positive control. After treatment with the negative control, the absorbance values were within the required acceptability criterion of 1.0 < mean OD < 2.5. The positive control showed clear irritating effects. Variation within tissues was acceptable (< 18%).

After the treatment with the test item, the relative absorbance values were reduced to 56.7%. This value is above the threshold for irritation potential (50%). Therefore, „2-propanol and 2-butanol production, distn. residue“ is considered as not irritant in the Human Skin Model Test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13. September 2010 - 28. September 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study under GLP, according to international guidelines and with full documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Elevage de Gérome (Quartier Labaste –F40260 Linxe)
- Age at study initiation: 11 or 15 weeks old
- Weight at study initiation: between 1.93 kg and 3.53 kg
- Housing: individual box

- Diet (e.g. ad libitum), Water (e.g. ad libitum): Drinking water (tap-water from public distribution system) and foodstuff (SDS - C15) were supplied freely.
- Acclimation period: a minimal 5-day acclimatisation period

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 to 23 °C
- Humidity (%): 30 to 70%
- Air changes (per hr): approximately fifteen changes per hour
- Photoperiod (hrs dark / hrs light): twelve hours continuous light (07.00 to 19.00) and twelve hours darkness

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

amount: 0.1 mL

Observation period (in vivo):

Ocular examinations were performed on both right and left eyes 1 hour, 24, 48 and 72 hours following treatment.
NOTE: As persistent reactions were noted at 72 hours post-dose, additional observations have been carried out from day 4 daily for up to 9 days in order to determine the reversible character of the lesions observed.

Number of animals or in vitro replicates:

3 males

Details on study design:

Eye examinations were carried out using the scale of lesion scores according to OECD 405.

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

fully reversible within: between days 7 and 9

Remarks on result:

other: a moderate redness noted 1 hour after the test item instillation

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

1.8

Max. score:

4

Reversibility:

fully reversible within: between days 7 and 8

Remarks on result:

other: a moderate to important chemosis noted 1 hour after the test item instillation

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

fully reversible within: one day

Remarks on result:

other: a congestion, noted 1 hour after the test item instillation in two animals

Irritation parameter:

cornea opacity score

Remarks:

opacity

Basis:

mean

Time point:

24/48/72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible within: 2 days

Remarks on result:

other: a moderate corneal opacity

INDIVIDUAL AND MEAN SCORES OF CONJUNCTIVAE, IRIS AND CORNEA

Animal n°	Time after treatment	Conjunctivae		Iris	Cornea
		Chemosis (A)	Redness (C )	Lesion (D)	Opacity (E )
A0356	24 hours	2	2	0	2
	48 hours	1	2	0	0
	72 hours	1	2	0	0
Total		4	6	0	2
Mean		1.3	2	0	0.7
A0374	24 hours	2	2	0	2
	48 hours	2	2	0	0
	72 hours	2	1	0	0
Total		6	5	0	2
Mean		2	1.7	0	0.7
A0375	24 hours	2	3	0	2
	48 hours	2	2	0	0
	72 hours	2	2	0	0
Total		6	7	0	2
Mean		2	2.3	0	0.7
Classificationin accordance with the European regulation		According to the calculated means, the test item has to be classified R36 "irritating to eyes".
Classificationin accordance with the GHS regulation		According to the calculated means, the test item has to be classified in category 2 "irritating to eyes" with the hazard statement H319 "causes serious eye irritation".

TOTAL AND INDIVIDUAL SCORES OF OCULAR IRRITATION

Animal No: A0356

Observation time	Conjunctivae				Iris		Cornea			Individual irritation index
	A	B	C	(A+B+C)x2	D	Dx5	E	F	ExFx5
				X=		Y=			Z=	X+Y+Z=
1 hour (D0)	2	3	2	14	1	5	0	0	0	19
24 hours (D1)	2	0	2	8	0	0	2	1	10	18
48 hours (D2)	1	0	2	6	0	0	0	0	0	6
72 hours (D3)	1	0	2	6	0	0	0	0	0	6
Day 4 (D4)	1	0	2	6	0	0	0	0	0	6
Day 5 (D5)	1	0	2	6	0	0	0	0	0	6
Day 6 (D6)	1	0	2	6	0	0	0	0	0	6
Day 7 (D7)	0	0	2	4	0	0	0	0	0	4
Day 8 (D8)	0	0	1	2	0	0	0	0	0	2
Day 9 (D9)	0	0	0	0	0	0	0	0	0	0

Animal No: A0374

Observation time	Conjunctivae				Iris		Cornea			Individual irritation index
	A	B	C	(A+B+C)x2	D	Dx5	E	F	ExFx5
				X=		Y=			Z=	X+Y+Z=
1 hour (D0)	3	3	2	16	1	5	0	0	0	21
24 hours (D1)	2	0	2	8	0	0	2	1	10	18
48 hours (D2)	2	0	2	8	0	0	0	0	0	8
72 hours (D3)	2	0	1	6	0	0	0	0	0	6
Day 4 (D4)	1	0	1	4	0	0	0	0	0	4
Day 7 (D7)	1	0	0	2	0	0	0	0	0	2
Day 8 (D8)	0	0	0	0	0	0	0	0	0	0

Animal No: A0375

Observation time	Conjunctivae				Iris		Cornea			Individual irritation index
	A	B	C	(A+B+C)x2	D	Dx5	E	F	ExFx5
				X=		Y=			Z=	X+Y+Z=
1 hour (D0)	3	3	2	16	0	0	0	0	0	16
24 hours (D1)	2	0	3	10	0	0	2	1	10	20
48 hours (D2)	2	0	2	8	0	0	0	0	0	8
72 hours (D3)	2	0	2	8	0	0	0	0	0	8
Day 4 (D4)	1	0	1	4	0	0	0	0	0	4
Day 7 (D7)	1	0	0	2	0	0	0	0	0	2
Day 8 (D8)	0	0	0	0	0	0	0	0	0	0

Interpretation of results:

Category 2A (irritating to eyes) based on GHS criteria

Conclusions:

In conclusion, the results obtained, under these experimental conditions, enable to conclude that the test item „2-propanol and 2-butanol production, distn. residue“ has to be classified in accordance with the Regulation EC No. 1272/2008 on classification, labelling and packaging of substances and mixtures, in category 2 “Irritating to eyes”. The signal word “Warning” and hazard statement H319 “Causes serious eye irritation” are required.

Executive summary:

Acute eye irritation was assessed for „2-propanol and 2-butanol production, distn. residue“ according to OECD guideline No 405. The test item was instilled as supplied, into the eye of 3 New Zealand rabbits at the dose of 0.1 mL. The experimental protocol was established on the basis of the official method as defined in the OECD guideline No 405 dated April 24th, 2002 and the test method B.5 of the Council regulation No 440/2008. The ocular reactions observed during the study have been moderate to important and totally reversible in the three animals:

- at the conjunctivae level: a moderate redness noted 1 hour after the test item instillation and totally reversible between days 7 and 9, associated with a moderate to important chemosis noted 1 hour after the test item instillation and totally reversible between days 7 and 8,

- at the iris level: a congestion, noted 1 hour after the test item instillation in two animals, and totally reversible on day 1.

- at the corneal level: a moderate corneal opacity, noted 24 hours after the test item instillation, and totally reversible on day 2.

In accordance with the Regulation EC No. 1272/2008 on classification, labelling and packaging of substances and mixtures, the test item has to be classified in category 2 “Irritating to eyes”. The signal word “Warning” and hazard statement H319 “Causes serious eye irritation” are required.

Reference 2

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26/08/2010-13/09/2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Fully documented study run under GLP and according to international guidelines

Qualifier:

according to guideline

Guideline:

other: OECD 437 “Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants”

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

other: bovine cornea

Controls:

yes, concurrent positive control

yes, concurrent negative control

Irritation parameter:

in vitro irritation score

Value:

11.7

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Table 1: Opacity Values

Test Group	Absorption at 570 nm before exposition	Opacity before exposition	Absorption at 570 nm after exposition	Opacity after exposition	Opacity Difference
Negative Control 0.9% NaCl	0.1960	1.5704	0.2099	1.6215	0.0511
	0.1879	1.5414	0.2431	1.7504	0.2090
	0.1879	1.5479	0.2417	1.7445	0.1966
Test substance	0.1450	1.3963	0.3016	2.0027	0.6064
	0.1969	1.5736	0.4861	3.0629	1.4893
	0.2138	1.6361	0.5943	3.9291	2.2930
Positive Control 10% NaOH	0.1516	1.4177	2.0405	109.7837	108.3660
	0.2301	1.6986	2.0670	166.6820	144.9835
	0.1636	1.4576	2.1933	156.0522	154.5947

Table 2: Optical density at 490 nm

Repl.	Negative Control			Test substance			Positive Control
1	0.043	0.054	0.045	0.255	0.448	0.659	1.640	1.738	1.242
2	0.056	0.062	0.042	0.260	0.447	0.664	1.632	1.716	1.265
3	0.043	0.052	0.042	0.261	0.445	0.675	1.639	1.722	1.251
Mean	0.047	0.056	0.043	0.259	0.447	0.666	1.637	1.725	1.253
Net	-0.026	-0.017	-0.030	0.186	0.374	0.593	1.564	1.652	1.180
Net – Neg. Contr.				0.210	0.398	0.617	1.588	1.676	1.204

Tab. 3: IVIS

Test Group	IVIS	Mean IVIS	Relative Standard Deviation IVIS
Negative Control 0,9% NaCl	-0.6099	-0.4660 = 0.00	-45.4%
	-0.2232
	-0.5661
Test substance	5.7934	11.6920	51.5%
	11.4559
	17.8275
Positive Control 10% NaOH	148.5869	163.6940	11.6%
	157.4416
	185.0528

Interpretation of results:

Category 2B (mildly irritating to eyes) based on GHS criteria

Remarks:

Criteria used for interpretation of results: other: criteria defined in “Bovine Corneal Opacity and Permeability (BCOP) Assay”, SOP of Microbiological Associates Ltd., UK, Procedure Details, April 1997; Gautheron et al. (1992), refined by Vanparys et al. (1994)

Conclusions:

According to this test, the test item „2-propanol and 2-butanol production, distn. residue“ possesses mild eye irritation potential.

Executive summary:

The potential for eye irritation of „2-propanol and 2-butanol production, distn. residue“ was tested according to the OECD 437 guideline under GLP. One valid experiment was performed.

The test item reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) was brought onto the cornea of a bovine eye which had been incubated with cMEM without Phenol red at 32 ±1 °C for one hour and whose opacity had been measured. The test item was incubated on the cornea for 10 minutes at 32 ±1 °C. After removal of the test item and two hours post-incubation, opacity and permeability values were measured.

Physiological sodium chloride solution was used as negative control. The negative control showed no irritating effect on the cornea.

10% sodium hydroxide solution was used as positive control. The positive control induced a severe irritation on the cornea.

The test item „2-propanol and 2-butanol production, distn. residue“ showed mild effects on the cornea of the bovine eye. The calculated IVIS (in vitro irritancy score) is 11.6920.

In conclusion, it can be stated that in this study and under the experimental conditions reported, the test item „2-propanol and 2-butanol production, distn. residue“ possesses mild eye irritation potential.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

One in vitro skin irritation study conducted under GLP showed that „2-propanol and 2-butanol production, distn. residue“ is not irritating to skin. However, the substance 2-methyl-pentane which is classified as skin irritating 2 in Annex VI of the CLP Regulation, is also present in „2-propanol and 2-butanol production, distn. residue“ as a component. As the concentration of 2-methyl-pentane observed in other samples of the substance may trespass the concentration limit for classification as skin irritating 2 (10% w/w), „2-propanol and 2-butanol production, distn. residue“ was precautionary classified as skin irritating, based on concentration ranges in boundary composition, even if the result of the in vitro skin irritation study (test sample contained 8.7% C6-alkanes) indicated no irritating effect.

One in vivo eye irritation study conducted under GLP and according to OECD 405 (key study) showed eye irritation. A previously conducted in vitro study according to the stepwise testing approach (according to OECD 437, BCOP test) showed mild eye irritation.

The results of the in vivo eye irritation study cannot be used for quantitative risk assessment since no dose-response data are available. However, they are used for qualitative risk assessment which consists of classification into a risk category and definition of risk management measures.

Justification for selection of skin irritation / corrosion endpoint:

No adverse effect observed based on experimental study, but skin irritating based on calculation method

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: irritating

Justification for classification or non-classification

One in vitro skin irritation study conducted under GLP showed that „2-propanol and 2-butanol production, distn. residue“ is not skin irritant. However due to the observation of the impurity 2-methyl-pentane in concentration above the concentration limit for classification in some samples of „2-propanol and 2-butanol production, distn. residue“ the substance is classified as irritating to skin, category 2, H315.

One in vivo eye irritation study conducted under GLP according to OECD 405 (key study) showed eye irritation. A supporting in vitro study (according to OECD 437, BCOP test) showed mild eye irritation.

Consequently, „2-propanol and 2-butanol production, distn. residue“ has to be classified as eye irritating (Irritating to eyes cat. 2, H319) and skin irritating (Irritating to the skin cat. 2, H315) according to the criteria of Regulation (EC) No 1272/2008.