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Scheduling delegate's interim decisions and invitation for further comment: ACCS/ACMS, March 2016

Scheduling medicines and poisons

12 May 2016

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1.8 BIS-Isobutyl PEG/PPG

Part A - Interim decisions on scheduling proposals referred to an advisory committee (March 2016)

1. Advisory Committee on Chemicals Scheduling (ACCS#16)

1.8 BIS-Isobutyl PEG/PPG

Referred scheduling proposal
  • In response to issues raised in a NICNAS New Chemical Assessments public report, the scheduling proposal is to create a new Schedule 6 entry for Bis-Isobutyl PEG/PPG-20/35/Amodimethicone Copolymer with appropriate exemption and cut-off to regulate its use in rinse-off cosmetic products.
Scheduling application

The reasons for the request are:

  • Bis-Isobutyl PEG/PPG is an eye irritant, consistent with Schedule 6 factors.
  • Bis-Isobutyl PEG/PPG is a skin irritant, consistent with Schedule 5 factors.

Similar to other surfactant chemicals previously considered for Scheduling, the key risk is the eye irritation, particularly when considered in the context of the use in hair care products.

The NICNAS risk assessment determined that there was no unreasonable risk to the public when used at 1% concentration in rinse-off hair care products (the maximum concentration proposed by the notifier). However, there remains uncertainty as to the actual concentration cut-off at which eye damage may occur, as eye irritation data was only available for a solution containing the polymer at 30-50% concentration.

Specific issues/questions raised by the delegate

The Delegate's reasons for referring this substance to the Committee were: the key scheduling issues, on which the delegate requires ACCS advice, is whether the weak skin irritancy and severe eye irritancy potential of this silicone co-polymer warrants inclusion in either Schedule 5 or 6 because of its potential use in rinse-off cosmetic hair care products.

The Delegate sought advice from the Committee on the following questions:

  • Does the ACCS agree that the severe eye irritancy potential of this substance warrants listing in Schedule 6, consistent with SPF criteria, or is Schedule 5 a more appropriate listing based on the overall low toxicity profile?
  • Should a listing in the schedules be made specific for use in hair care products, in cosmetics, or in all types of products?
  • Is the INCI name (Bis-Isobutyl PEG/PPG-20/35/Amodimethicone Copolymer) an appropriate name for listing in the schedules?
  • Is there sufficient information to propose a cut-off to exempt? For example, is the 1% concentration an appropriate cut-off concentration, as suggested in the NICNAS report?
  • What entries should be proposed for Appendices E and F?
  • Dimethicone (listed in Appendix B) appears to be the only other silicone copolymer considered for scheduling. Does a scheduling listing for bis-Isobutyl PEG/PPG-20/35/Amodimethicone Copolymer have implications for other similar copolymers?
Substance summary

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Please refer to the New Chemical assessment report for Siloxanes and Silicones, 3-[(2-aminoethyl)amino]propyl Me, di-Me, hydroxy- and methoxy-terminated, polymers with polyethylene-polypropylene glycol bis(2-methyl-2-propen-1-yl) ether (Word,77kb). This report is publicly available on the NICNAS website.

Acute toxicity

The toxicological investigations were conducted on the polymer at 30-50% concentration, unless stated otherwise. The acute toxicity end-points for bis-Isobutyl PEG/PPG-20/35/Amodimethicone Copolymer are listed in the below table.

Toxicity Species Result SPF* Classification
Acute oral toxicity LD50 (mg/kg bw) Rat > 2,000 Schedule 5
Acute dermal toxicity LD50 (mg/kg bw) Not provided Not provided -
Acute inhalational toxicity LC50 (mg/m3/4h) Not provided Not provided -
Skin irritation Rabbit Slightly irritating (at 10% concentration)** Schedule 5
Eye irritation Rabbit Severely irritating Schedule 6
Skin sensitisation Not provided Not provided -

*Scheduling Policy Framework for Medicines and Chemicals (SPF, 2015)

** A 10% suspension of the product (containing the polymer at 30-50% concentration) was used as a test substance in the study.


In a study conducted on rabbits the polymer at 30-50% was determined to be severely irritating to eyes, based primarily on conjunctival irritation, including effects which had not reversed by the end of the observation period.

A 10% suspension of the product (containing the polymer at 30-50% concentration) was found to be slightly irritating to the skin when tested on rabbits.

Repeat-dose toxicity

No information was provided.


The polymer was not mutagenic in a bacterial reverse mutation study and it was not clastogenic in an in vitro mammalian chromosome aberration test.


No information was provided.

Reproduction and developmental toxicity

No information was provided.

Observation in humans

No information was provided.

Public exposure

There will be repeated exposure of the public to the polymer (at up to 1% concentration) through the use as a surfactant in rinse off hair care products, such as shampoos and conditioners. The principal routes of exposure will be dermal, while ocular and oral exposures are also possible.

International regulations

No information was provided.

Current scheduling status

Bis-Isobutyl PEG/PPG is not specifically scheduled.

Relevant scheduling history

Bis-Isobutyl PEG/PPG has not been previously considered for scheduling, therefore scheduling history is not available.

Pre-meeting public submissions

One public submission was received. The submission noted the substance is intended for use in dilute, rinse off cosmetic products. They agree the hazard profile merits scheduling consideration but questioned whether the risks require risk mitigation through scheduling and if they would deliver safety benefits for the end user. They believe use of first aid statement E1 "If in eyes wash out immediately with water." normally applied to severe eye irritants is redundant, because under the intended use situation (rinse-off cosmetic, e.g. shampoo or conditioner), if the product was to enter the eye, the user would instinctively wash the eye immediately under water. They note there are no restrictions on the use of this polymer internationally. They suggest that if any scheduling restrictions are considered, the focus should be on uses that are not its current intended use to deter unintended uses, and allow this polymer to remain unscheduled when in rinse-off cosmetic preparations.

The public submission is available at: Public submissions on scheduling matters.

ACCS advice to the delegate

In response to the Delegate's questions, the Committee has advised that the toxicity of the substance warrants a Schedule 6 entry with an exemption for rinse off hair products below 1%, and entries in Appendix E and F.

The committee recommends that a new Schedule 6 entry be created Bis-Isobutyl PEG/PPG-20/35/Amodimethicone Copolymer as follows:

Schedule 6 - New entry

BIS-ISOBUTYL PEG/PPG-20/35/AMODIMETHICONE COPOLYMER except in rinse-off hair products containing 1 per cent or less of bis-isobutyl PEG/PPG-20/35/amodimethicone copolymer.

Appendix E, Part 2 – New entry


Standard statements: A, E1

Appendix F, Part 3 – New entry


Safety direction: 1 (avoid contact with eyes)

The matters under subsection 52E (1) of the Therapeutic Goods Act 1989 considered relevant by the Committee included: c) There are minimal risks to the user if the product containing the polymer is used as directed; b) The substance is used in rinse off cosmetics specifically shampoos and conditioners. It is widely used by the public and the hairdressing profession; c) The substance is a severe eye irritant consistent with schedule 6 criteria.

Delegate's considerations

The delegate considered the following in regards to this proposal:

  • Scheduling proposal;
  • Public submissions received;
  • ACCS advice;
  • Section 52E of the Therapeutic Goods Act 1989;
  • Scheduling factors8;
  • Other relevant information.
Delegate's interim decision

The delegate notes, and accepts, ACCS advice that a new listing for this silicone copolymer be created in Schedule 6, with appropriate listings in Appendices E and F to require relevant label First Aid and Warning Statements. The preferred name for listing is the INCI name Bis-Isobutyl PEG/PPG-20/35/Amodimethicone Copolymer. While the acute toxicity profile is possibly consistent with SPF criteria for listing in Schedule 5, the delegate agrees that a primary listing in Schedule 6 is more appropriate, given the strong eye irritancy potential. The delegate agrees to include a specific exemption to the Schedule 6 entry only for use in rinse-off cosmetic products at concentrations of 1% or less.

The delegate has broadened the schedule entry recommended by the ACCS to include an exemption for all rinse-off cosmetic products, not just those used in preparations formulated for use on the hair.

The delegate notes the points raised in the industry submission, that scheduling does not achieve any useful risk mitigation because of the reduced potential for eye irritancy in dilute preparations and the lack of international controls over use in cosmetics. However, the delegate considers that the exemptions in the proposed Schedule 6 entry address these concerns and mandate appropriate labelling of products where the use pattern and higher concentrations that may be used could be associated with a higher potential for eye damage. The eye warning statement prescribed in Appendix F will only be applied to products that do not meet the Schedule 6 exemption.

The proposed implementation date is 1 June 2017. A later implementation date is proposed to allow for an orderly process of re-labelling of products already on the market.

The delegate considered the relevant matters under section 52E (1) of the Therapeutic Goods Act 1989: (b) the purposes for which a substance is to be used and the extent of use of a substance; and (c) the toxicity of a substance.

Schedule 6 - New entry

BIS-ISOBUTYL PEG/PPG-20/35/AMODIMETHICONE COPOLYMER except in rinse-off cosmetic products containing 1 per cent or less of bis-isobutyl PEG/PPG-20/35/amodimethicone copolymer.

Appendix E, Part 2 – New entry


Standard statements: A, E1

Appendix F, Part 3 – New entry


Safety direction: 1


  1. Scheduling Policy Framework for Medicines and Chemicals (SPF, 2015)

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