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2019 Workplace Exposure Standards and Biological Exposure Indices


Water New Zealand have registered as a stake holder for the Worksafe 2019 Workplace Exposure Standards and Biological Indices work and will engage with members as the opportunity arise. For more information contact noel.roberts@waternz.org.nz. See below for the latest update. 


The 11th Edition of the Workplace Exposure Standards and Biological Exposure Indices Special Guide is published on the WorkSafe website here.

Table 1 below shows the WES that have been adopted in December 2019, and those for which we intend changing the WES in three years’ time.

Table 1 Changes to 11th Edition of WES & BEI Book

1,3-Butadiene Accept proposed 8-hour WES-TWA of 0.05 ppm
1,2-Dibromoethane Accept proposed 8-hour WES-TWA of 0.0003 ppm
2-Methoxyethanol Accept proposed 8-hour WES-TWA of 0.1 ppm
2-Methoxyethyl acetate Accept proposed 8-hour WES-TWA of 0.1 ppm
4,4-Methylene dianiline Accept proposed 8-hour WES-TWA of 0.002 ppm
Acetaldehyde Postpone change and re-review the proposal in regards to having only a Ceiling limit.
Acrylamide Accept proposed 8-hour WES-TWA of 0.0015 mg/m3
Acrylonitrile Accept proposed 8-hour WES-TWA of 0.05 ppm
Antimony trioxide Accept proposed 8-hour WES-TWA of 0.1 mg/m3
Carbon disulphide Accept proposed 8-hour WES-TWA of 1 ppm
Dichlorvos Retain the current 8-hour WES-TWA of 0.1 ppm inhalable fraction and vapour and add a sen notation
Dimethyl sulphate Accept proposed 8-hour WES-TWA of 0.01 ppm
Epichlorohydrin Accept proposed 8-hour WES-TWA of 0.05 ppm and WES-STEL of 0.15ppm
Ethyl chloride Accept proposed 8-hour WES-TWA of 100 ppm and remove skin notation
Ethylene oxide Accept proposed 8-hour WES-TWA of 0.1 ppm and adopt a Skin and a Sen notation
Furfural Accept proposed 8-hour WES-TWA of 0.2 ppm
Glutaraldehyde Accept proposed WES-Ceiling of 0.05 ppm and remove the WES-STEL
Glycidol Accept proposed 8-hour WES-TWA of 2 ppm and adopt a skin notation
Hydrazine Accept proposed 8-hour WES-TWA of 0.0002 ppm
Hydrogen sulphide Interim WES-TWA of 5 ppm and STEL of 10 ppm over three years (from date of publication of 2019 WES book) with intention to go to WES-TWA of 1 ppm and STEL of 5 ppm after 3 years
Lead (Biological Exposure Index) A BEI of 20 g/dL (0.97 mol/L) of whole blood; a suspension (removal) level of 30 g/dL (1.45 mol/L) of whole blood for females not of reproductive capacity, and males; a suspension (removal) level of 10 g/dL (0.48 mol/L) of whole blood for females of reproductive capacity, and those pregnant and/or breastfeeding.
Malathion Accept proposed 8-hour WES-TWA of 1 mg/m3 inhalable fraction and vapour
Maleic anhydride Accept proposed 8-hour WES-TWA of 0.0025 ppm inhalable fraction and vapour
Naphthalene Accept proposed 8-hour WES-TWA of 0.5 ppm and WES-STEL of 2 ppmand adopt a Skin notation
n-Butyl acrylate Accept proposed 8-hour WES-TWA of 2 ppm and WES-STEL of 4 ppm
n-Butyl glycidyl ether Accept proposed 8-hour WES-TWA of 0.25 ppm and adopt a skin notation
Nitrogen dioxide Interim WES-TWA of 1 ppm over three years (from date of publication of 2019 WES book) with intention to go to WES-TWA of 0.2 ppm after three years
p-Dichlorobenzene Accept proposed 8-hour WES-TWA of 2 ppm and WES-STEL of 10ppm and adopt a Skin notation
Phenyl glycidyl ether Accept proposed 8-hour WES-TWA of 0.1 ppm and adopt a dsen notation
Phthalic anhydride Accept proposed 8-hour WES-TWA of 0.002 ppm inhalable fraction and vapour and adopt a skin notation
Propylene dichloride Accept proposed 8-hour WES-TWA of 5 ppm and remove the WES-STEL
Pyridine Accept proposed 8-hour WES-TWA of 1 ppm and adopt a skin notation
Silica (crystalline, all forms) Accept proposed 8-hour WES-TWA 0.05 mg/m3. Review the WES within the next three years.
Styrene (Biological Exposure Index) Accept proposed BEI of 400 mg mandelic acid plus phenylglyoxylic acid in urine per gram of creatinine, and 40 µg styrene/L urine
Sulphur dioxide Accept proposed WES-STEL of 0.25 ppm and remove the WES-TWA
Thiram Accept proposed 8-hour WES-TWA of 0.2 mg/m3 inhalable fraction and vapour
Vinyl cyclohexene dioxide Accept proposed 8-hour WES-TWA of 0.1 ppm
Wood dust Accept proposed 8-hour WES-TWA of 0.5 mg/m3 for hard wood dust. Retain the current WES-TWA of 2 mg/m3 for soft wood dust with an intention to lower it to 1 mg/m3 in three years.