Tin (inorganic)

​​October 2000

Extracted from Section 8.3.7 ‘Detailed descriptions of chemicals’ of the ANZECC & ARMCANZ (2000) guidelines.

The default guideline values (previously known as ‘trigger values’) and associated information in this technical brief should be used in accordance with the detailed guidance provided in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality.

Tin is a metallic element in Group IV of the Periodic Table (containing carbon, silicon, germanium, tin and lead) and is usually found as sulfide or oxide ores associated with igneous or volcanic rocks. World tin production in 1980 was 243,000 tonnes (Mance et al. 1988b). Tin is commonly used in tin plating, solders, alloys and specialty glass.

Inorganic tin most commonly occurs in the aquatic environment as Sn (IV), Sn(OH)3⁺ (Mance et al. 1988a). Other forms predominate at lower pH. Its concentration in ocean waters is around 0.01 µg/L (Mance et al. 1988b). The current analytical practical quantitation limit (PQL) for inorganic tin is 0.05 µg/L in fresh water and 2 µg/L in marine water (NSW EPA 2000).

Aquatic toxicology

There are limited data on the toxicity of inorganic tin to aquatic organisms, particularly to marine species. Available data indicates low to moderate toxicity (Mance et al. 1988b).

Freshwater fish: Oncorhynchus mykiss, 24-hour LC50, 78,000 µg/L.

Freshwater crustaceans: one species, Daphnia magna, 48-hour LC50, 55,000 µg/L.

Freshwater insects: one species Chironomus plumosus, 96-hour LC50 of 3600 µg/L.

Freshwater annelids: one species Tubifex tubifex, 96-hour LC50, 3000 to 30,000 µg/L.

Only the insect and annelid data could be screened.

Marine fish: Limanda limanda, 96 hours, no mortalities at saturation (35 µg/L) in seawater.

Marine invertebrate: Gammarus locusta, 24-day LC100 of 100 µg/L. This figure is uninterpretable given the solubility of tin in seawater (Mance et al. 1988b).
Marine diatom: two species, 72-hour EC50, 200 to 210 µg/L.

Guideline

There were insufficient data to derive a guideline for inorganic tin. A low reliability trigger value for freshwater of 3 µg/L was derived by applying an assessment factor (AF) of 1000 to the lowest Tubifex figure. In marine waters, application of an AF of 200 to the diatom figure gave an ECL of 1 µg/L. However, as no toxicity was found to saturation levels for fish and crustaceans, (Mance et al. 1988b), this is likely to be overprotective. The value of 10 µg/L, recommend in the UK (Mance et al. 1988b) from 0.25 of the saturated concentration of tin in seawater (35 µg/L) may better serve as a low reliability trigger value for inorganic tin in marine waters. These figures do not apply if the tin is present as organotins. They should only be used as indicative interim working levels.

References

ANZECC & ARMCANZ 2000. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Canberra.

Mance GA, O’Donnell AR & Smith PR 1988a. Proposed environmental quality standards for list II substances in water: Boron. ESSL TR 256. Water Research Centre, Medmenham, UK.

Mance GA, O’Donnell AR, Campbell JA & Gunn AM 1988b. Proposed environmental quality standards for list II substances in water: Inorganic tin. ESSL TR 254. Water Research Centre, Medmenham, UK.

NSW EPA 2000. Analytical Chemistry Section, Table of Trigger Values 20 March 2000, LD33/11, Lidcombe, NSW.