Summary Report on NSF International DWTU Test Results 1994-1998

June 29, 1998

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Table of Contents

• 1.0 Introduction
• 2.0 Requirements for Materials Used in DWTU's
  • 2.1 Formulation Review
  • 2.2 Testing
  • 2.3 Test Parameters
• 3.0 Results of Testing
  • 3.1 Summary Results
• Appendix I - ANSI/NSF Standard 53, Section 4 - Materials
  • 4 Materials
    • 4.1 Materials in contact with drinking water
    • 4.2 Temperature resistance
    • 4.3 Materials evaluation
      • 4.3.1 Analytical methods
      • 4.3.2 Exposure water
      • 4.3.3 Exposure
• Appendix II
• Appendix III

1.0 Introduction

This report summarizes the test results obtained by NSF International (NSF) on Drinking Water Treatment Units (DWTU) over the past five years, and itemizes and summarizes test failures and the resolution of those failures. NSF only has information on products for which the manufacturer has requested certification under one or more of the following Standards:

• ANSI/NSF 42 Drinking Water Treatment Units-Aesthetic Effects
• ANSI/NSF 44 Cation Exchange Water Softeners
• ANSI/NSF 53 Drinking Water Treatment Units - Health Effects
• ANSI/NSF 55 Ultraviolet Microbiological Water Treatment Systems
• ANSI/NSF 58 Reverse Osmosis Drinking Water Treatment Systems
• ANSI/NSF 62 Drinking Water Distillation Systems
  
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2.0 Requirements for Materials Used in DWTU's

2.1 Formulation Review

Formulation requirements are detailed in ANSI/NSF Standard 53, Section 4 (see Appendix I). These and all the material requirements which follow consistently appear in all six ANSI/NSF DWTU Standards. Complete formulation information is required for any material contacting potable water. It is desirable to have this information prior to extraction testing, and required prior to Certification. There are some materials, such as non-brass materials containing lead, which are rejected on the basis of formulation regardless of the test results. In general, material must meet one or more of the following criteria:

• The material is Certified under NSF 51 - Food Equipment Materials.
• The material is Certified under ANSI/NSF 61 - Drinking Water System Components - Health Effects.
• The material meets the requirements of the U.S. Code of Federal Regulations, Title 21 (Food and Drugs) for direct or indirect food contact, or an equivalent international regulation.
• The Material is corrosion-resistant stainless steel generally used in food equipment or is a CDA200 or CDA300 series brass meeting the U.S. Safe Drinking Water Amendments of 1986 regarding "lead free" (<8% lead). Note that brass containing more than 3-4% lead is unlikely to pass the DWTU testing.
• The material is of a suitable purity and is generally recognized as safe for the intended end us (i.e. carbon).
• A component individually listed under one of the six ANSI/NSF DWTU standards cited above.

2.2 Testing

All DWTU undergo extraction testing to verify that the materials of construction of the units do not contribute unacceptable levels of contaminants to the drinking water. The only exceptions are units which are made of all Certified material and are assembled in a manner that does not introduce new contaminants, provided any surface-area-to-volume limitation for each Certified material is met and that there are no concerns regarding the cumulative levels of contaminants from the selected materials.

Test requirements are also detailed in ANSI/NSF 53 (see Section 4.3 attached as Appendix I), and include the composition of the exposure water as well as exposure time and temperature. The exposure protocol is a three-exposure sequence. Generally, the entire DWTU is tested by following the manufacturer's flushing instructions and then filling the units with exposure water at an initial inlet static pressure of 340 kPa, and capped for a 24-hour static exposure period. Three 24-hour static exposures are composited for analysis of contaminants.

Note that exposures can be done with media, without media, or both. New units with adsorptive media are tested with and without media, to detect contaminants from the media and from the materials of construction of the housing, cap and associated plumbing. A previously-tested unit for which a change in media has been requested would be tested only with media, and a previously tested unit for which a change in housing material has been requested would be tested only without media.

2.3 Test Parameters

The required extraction testing parameters are specified in Table 1 of ANSI/NSF 53 which are attached as Appendix II. These include the metals and volatile organic chemicals regulated by the U.S. Environmental Protection Agency (EPA), as well as some additional unregulated metals (aluminum, nickel, and manganese), and some screening parameters such as total organic carbon, and Phenolics. Table 2 of ANSI/NSF 53, attatched as Appendix III, lists parameters which are only selected if the formulation information indicates that they could leach out of the unit. Other formulation-dependent parameters may be selected if they could present a health effects concern.

3.0 Results of Testing

3.1 Summary Results

During this product review period, there were 201 single-exposure tests (with or without media), and there were 98 double exposure tests (with and without media). Of those tests, there were 158 product failures, and a total of 214 parameter failures as there was more than one parameter failure in some of the tests. In cases where an extraction result indicates the unit is seriously contaminated with a compound of toxicological significance, such as a high level of Acrylonitrile or Lead, other compounds of toxicological significance, such as Cadmium or Styrene, may be included in the failure notice even though the actual level of extraction for that compound is less than the normal action level. This is done to ensure the client is aware of other potential problems in their product.

Table 1 itemizes the failed parameters, the number of times they have been involved with initial failures as well as the number of times a second or third failure has occurred involving that parameter. Table 2 itemizes the highest and lowest levels identified in a failure.

The Graphs represent the failures shown as initial failures in Table 1 where a graphical presentation is shown for each class of compounds. Graph 1 represents Inorganic Parameters, Graph 2 the Semivolatile Parameters, and Graph 3 the Volatile Parameters.

The Appendices are the referenced sections from Standard 53.

Table 1
DWTU Failures By Parameter

Parameters	Initial Failures		Retest Failures
Inorganic Parameters	Units	Percent*	Units	Percent*
	#	%	#	%
Aluminum	6	2	1	0.3
Antimony	15	5	4	1.3
Arsenic	2	0.7
Barium	1	0.3
Cadmium	2	0.7
Lead	11	3.7	2	0.7
Manganese	6	2	4	1.3
Nickel	2	0.7
Phenolics	7	2.3	3	1
TKN	5	1.7	3	1
Total Dissolved Solids	3	1
Zinc	1	0.3
Semivolatile Parameters	#	%*	#	%*
1,4-Dioxane	2	0.7	2	0.7
2-Ethyl hexanol	1	0.3
2-Phenyl-2-propanol	1	0.3
Acrylonitrile	13	4.4	2	0.7
Aniline	1	0.3
Bis-2-ethylhexyl phthalate	1	0.3
Dimethyl phthalate	1	0.3
Di-n-butyl phthalate	1	0.3
Melamine	1	0.3
N-Methyl-2-pyrrolidone	2	0.7	1	0.3
Thiourea	1	0.3
Total Organic Carbon (TOC)	6.3	21.1	19	6.4
Triphenyl phosphine oxide	1	0.3
Unknown Hydrocarbon	1	0.3
Volatile Parameters	#	%*	#	%*
1,2, Dichloroethane	1	0.3
1,2, Dichloropropane	3	1
Acetone	2	0.7	2	0.7
Benzene	1	0.3
Carbon disulfide	7	2.3	2	0.7
Chloroform	5	1.7	2	0.7
Chloromethane	1	0.3
Cyclohexanone	3	1	4	1.3
Dimethyl formamide	10	3.3
Formaldehyde	21	7	4	1.3
Methanol	6	2	2	0.7
Methylene chloride	4	1.3	2	1
Methylethyl ketone	12	4	10	3
Methyl-t-butyl ether	1	0.3
Styrene	2	0.7
Tetrahydrofuran	7	2.3	5	1.7
Toluene	1	0.3
1,1,1-Trichloroethane	1	0.3

Table 2
Highest and Lowest Failure Levels All results in Micrograms/Liter (ug/L) unless otherwise noted.

Parameters
Inorganic Parameters	Highest Level	Lowest Level
Aluminum	29 000	0.280
Antimony	14	7.4
Arsenic	100	57
Barium	220	*
Cadmium	18	6.4
Lead	410	11
Manganese	260	65
Nickel	540	190
Phenolics	930	52
TKN	15 mg/L	0.5 mg/L
Total Dissolved Solids	300 mg/L	17 mg/L
Zinc	7 900	*
Semivolatile Parameters
1,4-Dioxane	120	14
2-Ethyl hexanol	84	*
2-Phenyl-2-propanol	68	*
Acrylonitrile	100	5
Aniline	1.3	*
Bis-2-ethylhexyl phthalate	120	14
Dimethyl phthalate	2 000	*
Di-n-butyl phthalate	16	*
Melamine	160	*
N-Methyl-2-pyrrolidone	380 000	20
Thiourea	3	*
Total Organic Carbon (TOC)	540 mg/L	1.4 mg/L
Triphenyl phosphine oxide	3	*
Unknown Hydrocarbon	2 000	*
Volatile Parameters
1,2, Dichloroethane	28	*
1,2, Dichloropropane	59	8.5
Acetone	92	74
Benzene	0.5	*
Carbon disulfide	1 300	55
Chloroform	140	7.1
Chloromethane	0.6	*
Cyclohexanone	2 500	70
Dimethyl formamide	1 300	10
Formaldehyde	6 300	120
Methanol	7 300	87
Methylene chloride	120	13
Methylethyl ketone	2 400	67
Methyl-t-butyl ether	>1	*
Styrene	3	0.8
Tetrahydrofuran	3 100	60
Toluene	28	*
1,1,1-Trichloroethane	25	*

Graph 1

Graph 2

Graph 3

Appendix I - ANSI/NSF Standard 53, Section 4 - Materials

4 Materials

4.1 Materials in contact with drinking water

Materials in contact with drinking water shall not impart levels of extractable contaminants that exceed the MDWLs specified in tables 1 and 2 when evaluated and tested in accordance with 4.3.

4.1.1 Complete formulation information on any material not certified as specifically compliant with the sections of the US Code of Federal Regulations, Title 21, listed in table 3, shall be reviewed to determine whether the material presents a health effects concern in contact with drinking water and to assess the material's potential for contributing contaminants to the drinking water.

NOTE - As a minimum for those materials requiring submission of formulation information, the complete chemical identity or proportion by weight (in some cases approximate weights or proportions may suffice), ingredient sources of supply, documentation regarding the health effects concern of each ingredient in the material, and documentation regarding the suitability of each ingredient for use in potable-water-contact material shall be provided.

4.1.2 If the level of an extractable contaminant exceeds the GMP level in tables 1 or 2, the manufacturing practices shall be reviewed to determine if reasonable means exist to further reduce or eliminate the contaminant.

NOTES - When an extractable contaminant has a GMP level set below the MDWL or health effects concern level, and the first exposure result is below the MDWL, the test exposure sequence in 4.3.3.2 may be repeated three times to determine if, at the end of the third exposure sequence, the concentration of the extractable contaminant is reduced to a level less than or equal to the GMP level. If all reasonable corrective actions are taken and the system does not impart a level of extractable contaminant that exceeds the GMP level at the end of the third exposure sequence, the system shall be considered to meet the requirements of this Standard.

If the GMP level is exceeded at the end of the third exposure sequence, all reasonable corrective actions are taken, and the MDWL or health effects concern level is not exceeded, the system may be considered to meet the requirements of this Standard.

4.1.3 Whole-system extraction testing may be waived if components, when separately tested, meet the requirements of this Standard and are assembled in a manner that does not introduce any new components, increase the surface area-to-volume ratio of previously evaluated components, or present potential concern based on cumulative factors.

4.2 Temperature resistance

Materials shall be tested in accordance with 4.3 to verify suitable temperature resistance.

4.3 Materials evaluation

4.3.1 Analytical methods

All analyses shall be conducted in accordance with the applicable method(s) referenced in 2.

4.3.2 Exposure water

Systems and components shall be exposed to locally available tap water that has been adjusted to contain 50 mg/L ± 5 mg/L total dissolved solids, 0.5 mg/L ± 0.05 mg/L free available chlorine, and to have a pH of 6.75 ± .25.

4.3.2.1 Exposure water used to evaluate systems or components designed for exclusive application on cold water lines shall be 23°C ± 2°C (73°F ± 3°F).

4.3.2.2 Exposure water used to evaluate systems or components designed for exclusive application on hot water applications shall be 82°C ± 5°C (180°F ± 10°F).

4.3.2.3 Exposure water used to evaluate systems or components that may be subjected to occasional short-term hot water exposure shall be 74°C ± 5°C (165°F ± 10°F).

4.3.3 Exposure

4.3.3.1 The system or component(s) of a system shall be installed, flushed, and conditioned in accordance with the manufacturer's instructions using the exposure water specified in 4.3.2 and an initial inlet static pressure of 340 kPa (50 psig).

4.3.3.2 The system or component(s) shall be refilled with exposure water specified in 4.3.2 and maintained for 24 hours at a temperature of 23°C ± 2°C (73°F ± 3°F). A two liter water sample shall then be collected. The system or component(s) shall be flushed according to the manufacturer's instructions, refilled, and maintained for 24 hours at a temperature of 23°C ± 2°C (73°F ± 3°F). A two liter water sample shall be collected. The system or component(s) shall again be flushed according to the manufacturer's instructions, refilled, and maintained for 24 hours at a temperature of of 23°C ± 2°C (73°F ± 3°F). A two liter water sample shall be collected.

NOTE - Sufficient systems or components shall be exposed to provide the required volume of extractant water.

4.3.3.3 All samples collected shall be composited and analyzed in accordance with 4.1.

4.3.3.4 Systems with adsorptive or absorptive media shall be tested with and without the media.

Appendix II

ANSI/NSF Standard 53, Table 1 - Extraction testing parameters

Parameter	Maximum drinking water level (MDWL) mg/L	Good manufacturing practice (GMP)1 concentration mg/L	USEPA method(s)
aluminum	0.5	0.05 - 0.22	200.7, 200.8
antimony	0.006	--	200.8, 200.9, 204.2
arsenic	0.05	--	200.8, 200.9, 206.2
barium	2	0.05	200.7, 200.8
beryllium	0.004	--	200.7, 200.8, 200.9, or 210.2
cadmium	0.005	--	200.8, 200.9, 213.2
chromium	0.1	--	200.8, 200.9, 218.2
copper	1.3	0.05	200.7, 200.8
lead	0.015	0.005	200.8, 200.9, 239.2
manganese	--	0.05	200.7, 200.8
mercury	0.002	--	245.1
nickel	--	0.05	200.7, 200.8
selenium	0.05	--	200.8, 200.9, 270.2
thallium	0.002	--	200.8, 200.9, 279.2
phenolics	--	0.05	420.4
Total Organic Carbon (TOC)	--	1	415.2
Volatile organic compounds3
total	--	0.01	502.2
benzene	0.005	detected	502.2
carbon disulfide	--	0.05	GC/PID
carbon tetrachloride	0.005	--	502.2
1,2-dichloroethane	0.005	--	502.2
1,1-dichloroethylene	0.007	--	502.2
dichloromethane	0.005	--	502.2
1,2-dichloropropane	0.005	--	502.2
ethylbenzene	0.7	0.005	502.2
monochlorobenzene	0.1	0.005	502.2
styrene	0.1	0.005	502.2
tetrachloroethylene	0.005	--	502.2
toluene	1	0.005	502.2
total trihalomethanes	0.1	--	502.2
bromodichloromethane	--	0.005	502.2
bromoform	--	0.005	502.2
chlorodibromomethane	--	0.005	502.2
chloroform	--	0.005	502.2
1,1,1-trichloroethane	0.2	0.005	502.2
1,1,2-trichloroethane	0.005	--	502.2
trichloroethylene	0.005	--	502.2
vinyl chloride	0.002	detected	502.2
o-,m-,p-xylene	10	0.005	502.2

Appendix III

ANSI/NSF Standard 53, Table 2 - Formulation dependent parameters

Parameter	Maximum drinking water level (MDWL) mg/L	Good manufacturing practice (GMP)1 concentration mg/L	USEPA method(s)
total dissolved solids (TDS)	--	50	160.1
total kjeldahl nitrogen	--	0.5	351.4
tin	--	0.05	200.9
zinc	--	5	200.7
nitrate (as N)	10	1	300
nitrite (as N)	1	0.1	300
nitrate plus nitrite (as N)	10	1
sulfate	--	40	300
sulfite	--	0.5	377.1
acrylonitrile	--	0.005	GC/MS2
1,4-dioxane	--	0.005	GC/MS2
formaldehyde	--	0.5
di-2-ethylhexyl adipate	0.4		525.2
phthalate scan (includes):
butyl benzyl phthalate	0.1	0.01	525.2
di(2-ethylhexyl) phthalate	0.006
di-n-butyl phthalate	--	0.01
di-n-butyl phthalate	--	0.01
diethyl phthalate	--	0.01
diethyl phthalate	--	0.01
polynuclear aromatics (includes):
naphthalene	--	0.001	550.1
acenaphthylene	--	0.002
acenaphthene	--	0.001
fluorene	--	0.0002
phenanthrene	--	0.0001
anthracene	--	0.0001
fluoranthene	--	0.0002
pyrene	--	0.0001
benzo(a)anthracene	--	0.0001
chrysene	--	0.0002
benzo(b)fluoranthene	--	0.0002
benzo(k)fluoranthene	--	0.0002
benzo(a)pyrene	0.0002	--
dibenzo(a,h)anthracene	--	0.0003
benzo(g,h,i)perylene	--	0.0002
indeno(1,2,3-cd)pyrene	--	0.0004
nitrosamines (includes):
n-nitroso-di-n-butyl amine	--	0.001 (detected)	625
n-nitrosodimethylamine	--	0.001 (detected)
n-nitrosodiphenylamine	--	0.001 (detected)
n-nitroso-di-n-propylamine	--	0.001 (detected)
acetone	--	0.05	GC/FID or PID3
cyclohexanone	--	0.05	GC/FID or PID3
methyl ethyl ketone	--	0.05	502.2
methanol	--	0.05	GC/FID
tetrahydrofuran	--	0.05	GC/FID or PID3