Exposure limits for hazardous substances are set to limit exposure to people, the environment and to control exposure in places of work. Exposure limits are enforceable controls applied to approved substances.
Tolerable exposure limits (TELs)
Tolerable exposure limits (TELs) limit public exposure to toxic substances. They do not apply to a place of work if the public does not have access to that place. Toxic substances are those with a HSNO classification in Class 6. A TEL is the maximum concentration of a hazardous substance legally allowable in a particular environmental medium, such as air, water, soil or a surface that the substance may be deposited onto. TELs are derived from potential daily exposure (PDE) values, which in turn are derived from acceptable daily exposure (ADE)/reference dose (RfD) values. The circumstances under which TELs are set are described in the Hazardous Substances (Classes 6, 8 and 9 Controls) Regulations 2001 (Part 2).
Environmental exposure limits (EELs)
An environmental exposure limit (EEL) establishes the maximum concentration of an ecotoxic substance legally allowable in a particular environmental medium (e.g. water, soil or sediment), including deposition of a substance onto surfaces (e.g. as in spray drift deposition).
Ecotoxic substances are those with a HSNO classification in Class 9. EELs apply outside an application area, and in the case of discharges to water apply after reasonable mixing.
Only one environmental exposure limit for a Class 9 substance may apply to an environmental medium at any given time or in any given circumstance. The circumstances under which EELs are set are described in the Hazardous Substances (Classes 6, 8 and 9 Controls) Regulations 2001 (Part 3).
Note: Resource consent requirements set by regional councils may be more stringent than the HSNO requirements, but not less restrictive. The proviso is that existing resource consents are not affected by HSNO until they are subject to review under section 128 of the Resource Management Act 1991.
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Workplace exposure standard (WES)
A workplace exposure standard (WES) is designed to protect persons in the workplace from the adverse effects of toxic substances. A WES is an airborne concentration of a substance (expressed as milligrams of substance per cubic metre of air or parts per million in air), which must not be exceeded in a workplace and only applies to places of work to which the public does not have access.
The circumstances under which WESs are set are described in the Hazardous Substances (Classes 6, 8 and 9 Controls) Regulations 2001 (regulations 29-30).
The Occupational Health and Safety Service (OSH) of the Department of Labour (DoL) is the primary agency responsible for setting workplace exposure standards. Their current list of standards may be obtained here:
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Exposure limit tables
These Tolerable exposure limits (TELs) and Environmental Exposure Limits (EELs) apply to a substance (or its components) if a TEL or EEL has been set for the substance by an approval under Part 5 of the HSNO Act. Some substances may have synonyms. The CAS Number should be used for unequivocal identification. The following tables were last updated on 1 August 2003.
Tolerable exposure limits (TELs)
| Substance |
CAS no. |
Air (mg per m3) |
Drinking water (mg per litre) |
Skin surface deposition (mg per m2) |
|---|
| Carbendazim |
10605-21-7 |
0.009 |
|
0.5 |
|---|
| Diflubenzuron |
35367-38-5 |
0.045 |
|
|
|---|
| Diuron |
330-54-1 |
|
0.02 |
|
|---|
| Guazatine |
108173-90-6 |
0.002 |
|
|
|---|
Dichloromethane
(Methylene chloride) |
75-09-2 |
3 |
|
|
|---|
| Moxidectin |
113507-06-5 |
|
|
0.03 |
|---|
| Praziquantel |
55268-74-1 |
|
|
2.83 |
|---|
| Pyrethrins |
8003-34-7 |
|
|
0.1 |
|---|
| Rotenone |
83-79-4 |
0.0003 |
0.006 |
|
|---|
| Thiram |
137-26-8 |
0.002 |
|
|
|---|
| Triclabendazole |
68786-66-3 |
|
|
0.05 |
|---|
Environmental exposure limits (EELs) - Water
| Substance |
CAS no. |
Water |
Fresh water |
Marine water |
|---|
2,2,4-trimethyl-1,3-pentanediol mono
(2-methylpropanoate) |
025265-77-4 |
0.0001 |
|
|
|---|
| 2,6-di-tert-butyl-p-cresol (BHT) |
128-37-0 |
0.014 |
|
|
|---|
| Bifenthrin |
82657-04-3 |
0.05 ng/L |
|
|
|---|
| Carbendazim |
10605-21-7 |
0.00014 |
|
|
|---|
| Copper (Cu2+) |
|
|
0.0014 |
0.0013 |
|---|
| Cyproconazole |
94361-06-5 |
0.77 ng/L |
|
|
|---|
| Diflubenzuron |
35367-38-5 |
|
0.00037 |
0.0002 |
|---|
| Diuron |
330-54-1 |
|
0.0002 |
0.0018 |
|---|
| Esbiothrin |
584-79-2 |
0.000089 |
|
|
|---|
| Fenhexamid |
126833-17-8 |
|
0.013 |
|
|---|
| Glyphosate |
1071-83-6 |
3.6 |
|
|
|---|
| Guazatine |
108173-90-6 |
0.00013 |
|
|
|---|
| Imidacloprid |
138261-41-3 |
0.000038 |
|
|
|---|
| Iodocarb |
55406-53-6 |
0.0001 |
|
|
|---|
| Iodosulfuron-methyl-sodium |
144550-36-7 |
16 ng/L |
|
|
|---|
| Irgarol |
28159-98-0 |
0.000024 |
|
|
|---|
| Ivermectin |
70288-86-7 |
|
0.1 ng/L |
0.1 ng/L |
|---|
Metsulfuron-methyl (also as degradation
product of Iodosulfuron-methyl) |
74223-64-6 |
8 ng/L |
|
|
|---|
| Moxidectin |
113507-06-5 |
0.3 ng/L |
|
|
|---|
| Octhilinone |
26530-20-1 |
0.00009 |
|
|
|---|
| Permethrin |
52645-53-1 |
0.0001 |
|
|
|---|
| d-Phenothrin |
51186-88-0 |
3 ng/L |
|
|
|---|
| Prallethrin |
23031-36-9 |
4 ng/L |
|
|
|---|
| Propiconazole |
60207-90-1 |
0.0001 |
|
|
|---|
| Pyrethrins |
8003-34-7 |
0.00001 |
|
|
|---|
| Pyrimethanil |
53112-28-0 |
0.008 |
|
|
|---|
| Rotenone |
83-79-4 |
0.00025 |
|
|
|---|
| Thiram |
137-26-8 |
0.00001 |
|
|
|---|
| Tolylfluanid |
731-27-1 |
0.00006 |
|
|
|---|
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Environmental exposure limits (EELs) - Soil, Sediment, Application Rate
| Substance |
CAS no. |
Soil |
Sediment |
Application Rate |
|---|
2,2,4 trimethyl-1,3-pentanediol mono
(2-methylpropanoate) |
025265-77-4 |
|
|
|
|---|
| 2,6-di-tert-butyl-p-cresol (BHT) |
128-37-0 |
|
|
|
|---|
| Bifenthrin |
82657-04-3 |
|
|
|
|---|
| Carbendazim |
10605-21-7 |
|
|
|
|---|
| Copper (Cu2+) |
|
|
|
|
|---|
| Cyproconazole |
94361-06-5 |
|
|
|
|---|
| Diflubenzuron |
35367-38-5 |
|
|
40 g/m3 in compost; 4 g in 2.5 L
water/m2 as a drench |
|---|
| Diuron |
330-54-1 |
|
|
|
|---|
| Esbiothrin |
584-79-2 |
|
|
|
|---|
| Fenhexamid |
126833-17-8 |
|
|
|
|---|
| Glyphosate |
1071-83-6 |
|
|
|
|---|
| Guazatine |
108173-90-6 |
|
|
|
|---|
| Imidacloprid |
138261-41-3 |
0.001 |
0.001 |
|
|---|
| Iodocarb |
55406-53-6 |
|
|
|
|---|
| Iodosulfuron-methyl-sodium |
144550-36-7 |
0.00003 |
|
|
|---|
| Irgarol |
28159-98-0 |
|
|
|
|---|
| Ivermectin |
70288-86-7 |
|
|
|
|---|
Metsulfuron-methyl (also as degradation
product of Iodosulfuron-methyl) |
74223-64-6 |
0.00052 |
|
|
|---|
| Moxidectin |
113507-06-5 |
|
|
|
|---|
| Octhilinone |
26530-20-1 |
|
|
|
|---|
| Permethrin |
52645-53-1 |
|
|
|
|---|
| d-Phenothrin |
51186-88-0 |
|
|
|
|---|
| Prallethrin |
23031-36-9 |
|
|
|
|---|
| Propiconazole |
60207-90-1 |
|
|
|
|---|
| Pyrethrins |
8003-34-7 |
|
|
|
|---|
| Pyrimethanil |
53112-28-0 |
|
|
|
|---|
| Rotenone |
83-79-4 |
|
|
|
|---|
| Thiram |
137-26-8 |
|
|
|
|---|
| Tolylfluanid |
731-27-1 |
|
|
|
|---|