4.2 2-hydroxyethyl methacrylate (2-HEMA)

4 Interim decisions on proposed amendments referred to the Advisory Committee on Medicines and Chemicals Scheduling in joint session (Joint ACMS-ACCS #26, November 2020)

4.2 Interim decision in relation to 2-hydroxyethyl methacrylate (2-HEMA)

Interim decision

Pursuant to regulation 42ZCZN of the Regulations, a Delegate of the Secretary has, in relation to the proposed amendment, made an interim decision to amend the current Poisons Standard in relation to 2-hydroxyethyl methacrylate as follows:

Materials considered

In making this interim decision, the Delegate considered the following material:

• The application to amend the current Poisons Standard with respect to 2-hydroxyethyl methacrylate;
• The 122 public submissions, which included no written submissions, received in response to the pre-meeting consultation under regulation 42ZCZK of the Regulations;
• The advice received from the Advisory Committee on Medicines and Chemicals Scheduling in joint session (Joint ACMS-ACCS #26);
• Subsection 52E(1) of the Therapeutic Goods Act 1989, in particular (a) the risks and benefits of the use of a substance; (b) the purposes for which a substance is to be used and the extent of use of a substance; (c) the toxicity of a substance; (d) the dosage, formulation, labelling, packaging and presentation of a substance; and (f) any other matters considered necessary to protect public health;
• The Australian Health Ministers' Advisory Council's Scheduling Policy Framework (SPF 2018); and
• The Scheduling handbook: Guidance for amending the Poisons Standard.

Summary of Joint ACMS-ACCS advice to the Delegate

The Committee recommended that the current Schedule 5 entry for 2-hydroxyethyl methacrylate be amended as follows:

The Committee also advised an implementation date of 1 June 2021.

Members agreed that the relevant matters under section 52E(1) of the Therapeutic Goods Act 1989 included (a) risks and benefits of the use of the substance; (b) the purpose for which the substance is to be used and the extent of use; (c) the toxicity of the substance; (d) the dosage, formulation, labelling, packaging and presentation of the substance; and (f) any other matters that the Secretary considers necessary to protect public health.

The reasons for the advice included:

1. the risks and benefits of the use of a substance
   • The risk associated with 2-HEMA is likely to be low due to its low concentration.
2. the purposes for which a substance is to be used and the extent of use of a substance
   • Proposed novel use in a children's toy.
3. the toxicity of a substance
   • At low concentrations, 2-HEMA is not expected to be an irritant.
   • The main toxicity concern, sensitisation, is reduced at concentration below 1%, and will be very low.
4. the dosage, formulation, labelling, packaging and presentation of a substance
   • Proposed product contains 0.09% of the poison and is labelled with appropriate warnings
5. the potential for abuse of a substance

   Nil

6. any other matters that the Secretary considers necessary to protect public health
   • The Committee raised concerns that the product, if accidentally applied to the skin and exposed to sunlight, may cause burns. Members recommended that delegate consider additional label warnings regarding this.

Reasons for the interim decision (including findings on material questions of fact)

I have made an interim decision to amend the Schedule 5 entry for 2-hydroxyethyl methacrylate (2HEMA) and exclude preparations up to 0.1 per cent from scheduling. The reasons for my decision are set out below.

2HEMA was first scheduled in 2015, based on evidence presented in the 2014 AICIS (formally NICNAS) IMAP report. The identified areas of toxicity were skin sensitisation (limited data), moderate eye irritancy and slight skin irritancy (limited data). In the current scheduling consideration, the applicant has not presented any new data to support a cut-off of 1 per cent and I am not persuaded by the statement made by the applicant that the skin sensitisation "studies referenced appear to be for concentrations of 25 per cent and over. The substance is classified as a category 1 skin sensitiser [GHS] so wouldn't be considered hazardous at a concentration less than 1 per cent."

I note that the proposed product consists of a gel containing 0.09 per cent 2HEMA, added as an active ingredient (crosslinking monomer) of the product and not present as a residual monomer in a polymer. For this reason, I do not agree with the applicants statement that the proposed cut-off is equivalent to the 1 per cent exemption in the methyl-methacrylate Schedule 6 entry and ethyl-methacrylate Schedule 5 entry. This cut-off applies only to these two substances when present "as a residual monomer in a polymer" i.e. as unavoidable impurities.

In making my decision to exempt 2HEMA at the lower limit of 0.1 per cent, I have taken into account two closely related substances, hydroxyethyl acrylate and hydroxypropyl acrylate. Both these substances have been assigned "Specific Concentration Limits" for sensitisation of 0.2% by EU harmonised classifications, indicating they are considered potent sensitisers. I am satisfied that a concentration of 0.1 per cent is protective based on the use pattern of products containing 2HEMA and the likely toxicity end point of concern being skin sensitisation.

I note that no public submissions were received in response to the pre-meeting consultation under regulation 42ZCZK.

I agree with the Committee's finding that the relevant provisions of section 52E of the Therapeutic Goods Act 1989 are (a) risks and benefits of the use of the substance; (b) the purpose for which the substance is to be used and the extent of use; (c) the toxicity of the substance; (d) the dosage, formulation, labelling, packaging and presentation of the substance; and (f) any other matters that the Secretary considers necessary to protect public health.

Proposed implementation date

1 June 2021.