STAFF ADVICE
APP203849 – HomeSafe Ready-to-Use Weed Terminator
October 2019
1. Executive Summary
1.1 HomeSafe Ready-to-Use Weed Terminator is a ready-to-use aqueous solution containing acetic acid at 90 g/L as the active ingredient, plus other components. It is intended for use as herbicide for the control of weeds, grasses, moss and algae in home gardens.
1.2 The hazard classifications of HomeSafe Ready-to-Use Weed Terminator determined by the EPA are:
6.3B, 6.9B (inhalation) and 9.1B.
1.3 With the full suite of controls in place, the risks associated with the use of HomeSafe Ready-to-Use Weed Terminator can be adequately managed.
2. Application Context
Background
2.1 HomeSafe Ready-to-Use Weed Terminator is a ready to use aqueous solution containing acetic acid at 90 g/L as the active ingredient, plus other components. It is intended for use as herbicide for the control of weeds, grasses, moss and algae in home gardens.
2.2 The formulation of HomeSafe Ready-to-Use Weed Terminator is considered confidential by the applicant.
2.3 The active ingredient, acetic acid, is already present in three approved substances in higher concentrations than in HomeSafe Ready-to-Use Weed Terminator. These substances are used to control weeds in home gardens, recreational parks and pavements. Acetic acid is also present in many other approved substances in very low concentrations as pH regulator.
2.4 HomeSafe Ready-to-Use Weed Terminator will be used in similar ways to other approved substances with a higher concentration of acetic acid, however, HomeSafe Ready-to-Use Weed Terminator has a different set of hazard classifications. A Category A assessment is appropriate because the risks resulting from the classification difference can be qualitatively assessed.
Active ingredient
2.5 To allow evaluation of HomeSafe Ready-to-Use Weed Terminator, key aspects of acetic acid regulation have been summarised below.
Regulatory status
Table 1: Active ingredient regulatory status Active ingredient
name
Regulatory status and history in New Zealand
International regulatory status and history
(Australia, Canada, Europe, Japan, USA) Acetic acid (>80%
aqueous solution)
Approved (HSR000975) Approved: Australia, Europe, USA (under review)
2.6 Acetic acid has previously been approved in New Zealand for use as herbicide and pH regulator. It is available for both professional and non-professional users. It has also been approved internationally in Europe, USA and Australia for agricultural use.
2.7 There are existing formulations containing acetic acid, which are approved under the Act, and are highly similar to HomeSafe Ready-to-Use Weed Terminator in that they have a similar use pattern and a similar concentration of acetic acid (eg “Goulter's Vinegar Weed Killer - Ready to Spray 9.5%”, HSR101101).
2.8 The formulation of HomeSafe Ready-to-Use Weed Terminator is considered confidential by the applicant.
Regulatory parameters of active ingredient
Impurities and or restrictions on purity or composition
2.9 No impurity limits for acetic acid have been identified by FAO / APVMA.
Concentration and maximum application rate
2.10 The concentration of acetic acid in HomeSafe Ready-to-Use Weed Terminator is lower than in other approved substances with a similar use pattern.
Physical form and use pattern
2.11 HomeSafe Ready-to-Use Weed Terminator is formulated as a ready-to-use aqueous solution.
2.12 The intended use of HomeSafe Ready-to-Use Weed Terminator is as a herbicide on weeds, moss and algae in home garden settings. The use pattern is summarised in Table 2 and the full outline of
intended uses, application methods and application rates are detailed in the GAP table, Table 3.
Table 2: Summary of use pattern for HomeSafe Ready-to-Use Weed Terminator
Substance category
Wide dispersive use?
Home use? Concentration Application
rate(s) Remarks
Pesticide Yes ☐ No ☒ Yes ☒ No ☐ 90 g/L acetic
acid NA Spot
treatment
Table 3: GAP Table for HomeSafe Ready-to-Use Weed Terminator Crop
and/or situation (a)
Produc t Code
F G or I (b)
Pest or group of pests controlled (c)
Formulation Application
Application rate per treatment
Remarks (m)
Type (d-f)
Conc of as (i)
Method kind (f-h)
Growth stage and season (j)
Number min max (k)
Interval between applications (min) Control of weeds in
gardens, paths, driveways, around sheds and spot spraying in lawns and turf. Also controls moss and algae.
None F
Weeds in the home garden.
Aqueous solution
90 g/L acetic acid
Spraying No limit No limit As required Not relevant
Ready-to-use product for home garden
Remarks (a) For crops, the EU and Codex classifications (both) should be used; where relevant, the use situation should be described (eg fumigation of a structure) (b) Outdoor or field use (F), glasshouse application (G) or indoor application (I)
(c) eg biting and suckling insects, soil born insects, foliar fungi, weeds (d) eg wettable powder (WP), emulsifiable concentrate (EC), granule (GR) (e) GCPF Codes - GIFAP Technical Monograph No 2, 1989
(f) All abbreviations used must be explained
(g) Method, eg high volume spraying, low volume spraying, spreading, dusting, drench
(h) Kind, eg overall, broadcast, aerial spraying, row, individual plant, between the plants -type of equipment used must be described (i) g/kg or g/l
(j) Growth stage at last treatment (BBCH Monograph, Growth Stages of Plants, 1997, Blackwell, ISBN 3-8263-3152-4), including where relevant, season at time of application (k) The minimum and maximum number of applications possible under practical conditions ofuse must be provided
(l) PHI - minimum pre-harvest interval
(m) Remarks may include: extent of use, economic importance and restrictions
3. Hazard Assessment
Hazard classification of HomeSafe Ready-to-Use Weed Terminator
3.1 The hazard classifications of HomeSafe Ready-to-Use Weed Terminator determined by the EPA are:
6.3B, 6.9B (inhalation), 9.1B. Table 4 shows the method used for classification and indicates the main components that contribute to each hazard classification.
3.2 The classifications that have been applied to HomeSafe Ready-to-Use Weed Terminator are different to those submitted by the applicant. The applicant classified the substance as a metallic corrosive (8.1A), oral acute toxic (6.1E) and eye irritant (6.4A), while the EPA did not. The applicant classified the substance as skin irritant 6.3A, while the EPA gave a lower classification for this subclass (6.3B).
The applicant also classified the substance as 9.1D (slightly harmful to the aquatic environment), while the EPA classified it as 9.1B (ecotoxic in the aquatic environment).
Table 4: Hazard classification of HomeSafe Ready-to-Use Weed Terminator Mixture classification Method of
classification
Hazard Class/Subclass Applicant’s classification
EPA classification
Mixture data Read across Mixture rules1
Remarks
Class 1 Explosiveness NA No
☐ ☐ ☐
Class 2, 3 & 4 Flammability NA No
☐ ☐ ☐
Class 5 Oxidisers/Organic
Peroxides NA NA
☐ ☐ ☐
8.1 Metallic corrosiveness 8.1A ND
☐ ☐ ☒
Low concentration of 8.1A components (Acetic acid, component B)
6.1 Acute toxicity (oral) 6.1E No
☐ ☐ ☒
6.1 Acute toxicity (dermal) No No
☐ ☐ ☐
6.1 Acute toxicity (inhalation) No No
☐ ☐ ☐
6.1 Aspiration hazard ND ND
☐ ☐ ☐
6.3 Skin irritancy 6.3A 6.3B
☐ ☐ ☒
Component B andcomponent C
6.4 Eye irritancy 6.4A No
☐ ☐ ☒
6.5A Respiratory sensitisation ND ND
☐ ☐ ☐
Mixture classification Method of classification
Hazard Class/Subclass Applicant’s classification
EPA classification
Mixture data Read across Mixture rules1
Remarks
6.5B Contact sensitisation ND ND
☐ ☐ ☐
6.6 Mutagenicity ND ND
☐ ☐ ☐
6.7 Carcinogenicity ND ND
☐ ☐ ☐
6.8 Reproductive/ developmental
toxicity ND ND
☐ ☐ ☐
6.8 Reproductive/ developmental
toxicity (via lactation) ND ND
☐ ☐ ☐
6.9 Target organ systemic toxicity
(inhalation) 6.9B 6.9B
☐ ☐ ☒
Acetic acid9.1 Aquatic ecotoxicity 9.1D 9.1B
☐ ☐ ☒
Component C9.2 Soil ecotoxicity ND ND
☐ ☐ ☐
9.3 Terrestrial vertebrate ecotoxicity ND No
☐ ☐ ☐
9.4 Terrestrial invertebrate
ecotoxicity ND ND
☐ ☐ ☐
-: No information provided by the applicant
NA: Not Applicable. For instance, testing for a specific endpoint may be omitted if it is technically not possible to conduct the study as a consequence of the properties of the substance e.g. highly volatile, highly reactive or unstable substances cannot be tested; mixing of the substance with water may cause danger of fire or explosion; or the radio-labelling of the substance required in certain studies may not be possible.
ND: Not Determined. Data were unavailable for one or more components.
No: Data are available for the formulation or for all components and classification is not triggered.
1 Use of mixture rules may not adequately take into account interactions between different components in some circumstances and must be considered of lower reliability than data on the mixture itself.
2 Klimisch, H-J., Andrear, M., & U. Tillmann, 1997. A systematic approach for evaluating the quality of experimental toxicological and ecotoxicological data. Reg. Toxicol. Pharmacol. 25, 1–5 (1997)
4. Risk Assessment
4.1 It is considered that there is potential for significant exposure to people and the environment during the use phase of the lifecycle. Therefore, a qualitative risk assessment was undertaken to understand the likely exposures to the substance under the use conditions proposed by the applicant.
4.2 During the importation, manufacture, transportation, storage and disposal of this substance it is considered that the proposed controls and other legislative requirements will sufficiently mitigate risks to a negligible level.
4.3 This assessment takes into account the existing EPA Notices controls around packaging, identification and disposal of hazardous substances. In addition, the Land Transport Rule 45001, Civil Aviation Act 1990, Maritime Transport Act 1994 and New Zealand’s Health and Safety at Work (Hazardous Substances) (HSW (HS)) requirements all have provisions for the safe management of hazardous substances.
Human health risk assessment
4.4 HomeSafe Ready-to-Use Weed Terminator is intended to be supplied to the domestic market. Users are expected to apply the ready-to-use formulation from a hand trigger sprayer bottle for spot
treatment against weeds in home garden settings. It is likely that users will be exposed to the
substance during the application stage. Risks during other phases of the lifecycle are mitigated by the prescribed controls.
Skin irritancy (6.3B)
4.5 It is likely that skin exposure may occur during the use of this substance, but any effect is expected to be minimal. The substance is still irritating to the skin while wet, therefore additional label statements recommending the use of gloves when applying this substance and keeping people and pets away from treated area for at least 24 hours after application are proposed to mitigate the risk from the skin irritancy hazard to a negligible level.
Target organ toxicity via the inhalation route (6.9B)
4.6 It is considered likely that the substance is inhaled during the loading and application phases. The most likely route is spraying the substance in an upwind direction. The proposed GAP table does not limit the number of applications and does not specify the interval between applications, therefore the likelihood of repeated exposure with the substance is considered as likely as not. Any effect of multiple exposure over a long period of time is expected to be major.
4.7 An additional control is proposed to restrict the application method to spot treatment, with an additional label statement, to apply the substance only downwind. The proposed additional controls are found to be eligible to mitigate risk of target organ toxicity to a negligible level.
Environmental risk assessment
4.8 HomeSafe Ready-to-Use Weed Terminator is a herbicide that will be applied on weeds, mosses and algae in home gardens. Given its classification, this substance has the potential to affect aquatic organisms if significant exposure occurs.
Aquatic ecotoxicity (9.1B)
4.9 It is unlikely that aquatic organisms will be exposed to HomeSafe Ready-to-Use Weed Terminator, as application will be by spot treatment application method by hand triggered sprayer.
4.10 HomeSafe Ready-to-Use Weed Terminator is classified as ecotoxic in the aquatic environment and as such, it is expected that exposure may result in moderate effects to organisms. The classification of HomeSafe Ready-to-Use Weed Terminator triggers prescribed controls that do not fully mitigate the risk to the aquatic environment. It is therefore necessary to apply additional controls to minimise the likelihood of HomeSafe Ready-to-Use Weed Terminator entering waterways, and thus mitigate the risks to aquatic organisms to a negligible level. The additional controls should restrict the application to spot treatment.
Risk assessment conclusion
4.11 Risks during other phases of the lifecycle are mitigated by the prescribed controls.
4.12 With the proposed controls in place, the residual risks of the use of HomeSafe Ready-to-Use Weed Terminator are negligible.
5. Controls
Prescribed controls (EPA Notice controls)
5.1 The hazard classifications of HomeSafe Ready-to-Use Weed Terminator determine a set of prescribed controls specified by the EPA Notices. There are also requirements in the Health and Safety at Work (Hazardous Substance, HSW (HS)) Regulations under the HSW Act.
5.2 The prescribed controls set the baseline for how the substance should be managed and include specifications on how the substance is to be packaged, labelled, stored, disposed of, transported, handled and used. The prescribed controls also set information requirements (eg Safety Data Sheets), signage and emergency management.
Variations to prescribed controls
Exposure limits
5.3 No Tolerable Exposure Limit (TEL) has been set previously for the active ingredient in HomeSafe Ready-to-Use Weed Terminator because it is considered that exposure to this substance is not likely to result in an appreciable toxic effect to people, provided conditions of use are followed.
5.4 No Environmental Exposure Limit (EEL) value has been set previously for the active ingredient in HomeSafe Ready-to-Use Weed Terminator, as the level of risk of adverse effects to the environment has been qualitatively assessed as being negligible, with controls in place.
5.5 There are Workplace Exposure Standard (WES) values currently set for the active ingredient of HomeSafe Ready-to-Use Weed Terminator but, as they are not Prescribed Exposure Standard (PES) values, they are guidance values used for the management of health risk. No PES has been set for any component of HomeSafe Ready-to-Use Weed Terminator.
Labelling and identification
5.6 The name and concentration of the following component needs to be specified on the SDS:
Table 5: Component requiring identification SDS
Acetic acid (6.9B, WES)
Additional controls
Application restriction
5.7 This substance may only be applied using spot treatment application methods.
Labelling
5.8 Label statements recommending the use of gloves when using this substance, keeping people and pets away from treated area for at least 24 hours after application and limiting the application to downwind direction are recommended, in order to mitigate the risks from the skin irritancy and target organ toxicity hazards.
5.9 Label statements indicating:
“Users must wear gloves when applying this substance.”
“Keep people and pets away from the treated area for at least 24 hours after application.”
“Apply in a downwind direction.”
6. Conclusion
6.1 After taking into account the prescribed controls and any proposed variations and additions to these controls, it was concluded that the residual level of risk of any potentially significant adverse effects is negligible.
