User Guide to Thresholds and Classification - Environmental ...

112User Guide for Thresholds and Classifications8. Corrosive Properties – Class 88.1. IntroductionThe three subclasses under the corrosive property defined in the Hazardous Substances and NewOrganisms Act 1996 (HSNO Act) are:subclass 8.1 – substances corrosive to metals (see section 8.2);subclass 8.2 – substance corrosive to skin (see chapter 10 below); andsubclass 8.3 – substances corrosive to eyes (see chapter 11 below).The two subclasses that deal with corrosion of skin and eyes are addressed in chapters 10 and 11respectively, because they are an extension of the skin and eye irritancy subclasses.8.2. Corrosive to metals – subclass 8.18.2.1. Corrosive to metals hazard and classification criteriaCorrosive to metals threshold criteriaSchedule 5 to the Hazardous Substances (Minimum Degrees of Hazard) Regulations 2001 states:2 Minimum degrees of hazardA substance with corrosive properties is not hazardous for the purposes of the Act unless—(a) the substance corrodes, at a rate exceeding 6.25 millimetres per year at a test temperature of55°C,—(i) steel type P235 (ISO 9328 (II): 1991); or(ii) steel type SAE 1020 (Society of Automotive Engineers); or(iii) non-clad aluminium types SAE 7075-T6 or AZ5GU-T6.Corrosive to metals classification criteriaSchedule 5 to the Hazardous Substances (Classification) Regulations 2001 identifies one classificationsubclass for substances that are corrosive to metals (subclass 8.1).Subclass 8.1 – substances that are corrosive to metalsA subclass 8.1 classification and the subsequent category apply to any substance that meets thefollowing criteria.a. A substance that corrodes steel type P235 (ISO 9328 (II):1991), or steel type SAE 1020, or non-cladaluminium types SAE 7075-T6 or AZ5GU-T6 at a rate exceeding 6.25 millimetres per year at a testtemperature of 55°C.8.2.2. Acceptable test methodologyThe test methodology deemed to meet the requirements for testing the corrosion to metals threshold isStandard Practice for Laboratory Immersion Corrosion Testing of Metals (ASTM, 2004).January 2012 EPA0109