Lead Paint Standards

Available from:

Environmental Reference Materials, Inc.

P.O. Box 12527

Research Triangle Park, N.C. 27709

1-888-645-7645 (U.S. only)

FAX: 1-919-544-1669

These lead paint program testing standards are certified reference materials that have been developed to assist laboratories in meeting the quality control requirements of the American Industrial Hygiene Association’s (AIHA) Environmental Lead Laboratory Accreditation Program (ELLAP). The ELLAP accredits testing laboratories under the U.S. EPA’s National Lead Laboratory Accreditation Program.

They can be used as laboratory control standards or as spiking materials for paint, soil and wipes. These standards can also be used as practice samples for laboratories participating in the AIHA’s Environmental Lead Proficiency Analytical Testing Program (ELPAT). All products are certified for Lead content. In addition, products LCS-301 and 401 are certified for up to 15 additional elements. A summary of product information is presented below and complete certificates of analysis follow. Certificates of analysis for exhausted products and lots available on request.

Product No. and Name Unit Size Lead Content, ppm Unit Price $ NIST Traceable

ERM-6d Lead Free Paint 50g <10 $160 yes

ERM-7 Lead Free Soil 50g 8.4 $ 60 no

ERM-7a Lead Free Soil 50g <4 $160 yes

ERM-8c Low Level Lead in Paint 50g 577 $190 yes

ERM-9 Lead Paint in Soil 50g 558 $ 60 no

ERM-9a Lead Paint in Soil 50g 484 $160 yes

ERM-12a Lead Paint in Soil 50g 5273 $190 yes

LCS-301 Northeast Urban Soil 50g 547 $190 yes

LCS-401 Blended Paints from 50g 4430 $190 yes

Public Buildings

Revisions to certificates and products: For LCS-401, results for Mercury determined by EPA Method 7471A were added (4-3-06). Lead results by EPA Method 3052 were upgraded to NIST traceable (4-3-06). ERM-8b added to replace ERM-8a and LCS-402 (3-27-07). ERM-12a added to replace ERM-11 and LCS-302 (5-24-07). Gravimetric values for Lead added to certificates for ERM-12a (6-13-07) and 8b (12-12-07). All products shown in table above are available. ERM-7 expiration date extended (1-9-08). ERM-8b text corrected to state that mixture of paints and not paint and soil used to prepare product (5-31-08—since this is an editorial change, a new revision number was not assigned). ERM-8c added to replace ERM-8b (5-27-08).

ENVIRONMENTAL REFERENCE MATERIALS, INC.

P.O. BOX12527 RESEARCH TRIANGLE PARK, N.C. 27709 1-919-544-1669 1-888-OIL-SOIL

CERTIFICATE OF ANALYSIS

LEAD FREE PAINT

CAT. NO. ERM-6c

LOT NO. 6-05-2

DATE OF MANUFACTURE: 3-25-05

EXPIRATION DATE: 3-25-15

CERTIFIED VALUE FOR LEAD: <9 mg/kg

DESCRIPTION AND INTENDED USE:

Virgin latex house paint was evaporated to dryness, milled, sieved to pass a 2000-micron sieve and blended. The product was packaged sequentially in 50g units in glass bottles. Units from the beginning, middle and end of the packaging sequence were analyzed for Lead using EPA Method 6010B, Inductively Coupled Plasma-Atomic Emission Spectroscopy after digestion by EPA Method 3051, Microwave Assisted Acid Digestion of Sediments, Sludges, Soils and Oils. A two-way ANOVA of the resulting data showed that the within and between bottle analyses could be considered equivalent. All of the results were below the method detection limit of 9 mg/kg. Therefore, the product is considered homogeneous with respect to Lead. The results of the 15 determinations were pooled and the 95% prediction interval calculated. The certified value is the mean value of these determinations ± the uncertainty for the 95% prediction interval, which in this case, is <9. Laboratories should be able to obtain similar results using this method and a 0.1 g sample size. Use of smaller or larger sample sizes will potentially result in different detection limits and the acceptance range may need to be changed accordingly. This material was also analyzed for Lead along with NIST SRM 2582, Powdered Paint. The mean of the results of three determinations for Lead in SRM 2582 was 186.7 mg/kg, 89.4% of the certified value for Lead of 208.8 mg/kg. Because of the close agreement with the certified value for the SRM, the results for ERM-6b can be considered NIST traceable for Lead.

This material is intended to be used as a quality control standard in performing tests for Lead in paint by EPA Methods 6010B and 7420 and ASTM Methods E1613-94 and D3335-85a (1994). Tests for stability will be performed as necessary. Any changes in the certified value outside the 95% prediction interval will be reported to purchasers of this product. Due to the high latex content of the paint, it may be necessary to refrigerate it for several hours prior to analysis to ensure the product is a freely flowing solid. The product does not require any additional homogenization and there are no special storage requirements.

Approved by:

________________________ ___________

Alvia Gaskill, Jr., President Date

ENVIRONMENTAL REFERENCE MATERIALS, INC.

P.O. BOX12527 RESEARCH TRIANGLE PARK, N.C. 27709 1-919-544-1669 1-888-OIL-SOIL

CERTIFICATE OF ANALYSIS

LEAD FREE PAINT

CAT. NO. ERM-6d

LOT NO. 6-07-1

DATE OF MANUFACTURE: 6-28-07

EXPIRATION DATE: 6-28-17

CERTIFIED VALUE FOR LEAD: <10 mg/kg

DESCRIPTION AND INTENDED USE:

Virgin latex house paint was evaporated to dryness, milled, sieved to pass an 850-micron sieve and blended. The product was packaged sequentially in 50g units in glass jars. Units from the beginning, middle and end of the packaging sequence were analyzed for Lead using EPA Method 6010B, Inductively Coupled Plasma-Atomic Emission Spectroscopy after digestion by EPA Method 3050B, Acid Digestion of Sediments, Sludges and Soils. A two-way ANOVA of the resulting data showed that the within and between bottle analyses could be considered equivalent. All of the results were below the method detection limit of 10mg/kg. Therefore, the product is considered homogeneous with respect to Lead. The results of the 15 determinations were pooled and the 95% prediction interval calculated. The certified value is the mean value of these determinations ± the uncertainty for the 95% prediction interval, which in this case, is <10mg/kg. Laboratories should be able to obtain similar results using this method and a 0.4 g sample size. Use of smaller or larger sample sizes will potentially result in different detection limits and the acceptance range may need to be changed accordingly. This material was also analyzed for Lead along with NIST SRM 2582, Powdered Paint. The mean of the results of three determinations for Lead in SRM 2582 was 190.0 mg/kg, 92.9% of the certified value for Lead of 208.8 mg/kg. Because of the close agreement with the certified value for the SRM, the results for ERM-6d can be considered NIST traceable for Lead.

Approved by:

________________________ ___________

Alvia Gaskill, Jr., President Date

ENVIRONMENTAL REFERENCE MATERIALS, INC.

P.O. BOX 12527 RESEARCH TRIANGLE PARK, N.C. 27709 1-919-544-1669 1-888-OIL-SOIL

CERTIFICATE OF ANALYSIS

LEAD FREE SOIL

CAT. NO. ERM-7

LOT NO. 7-97-1

DATE OF MANUFACTURE: 11-14-97

EXPIRATION DATE: 1-9-12

REVISION 2: 1-9-08

CERTIFIED VALUE FOR LEAD: 8.39 ± 12.60 mg/kg

DESCRIPTION AND INTENDED USE:

A clean clay soil from a residential area was sieved to pass a 75-micron sieve and blended. The product was packaged sequentially in 5 g units in 7-mL glass vials. Units from the beginning, middle and end of the packaging sequence were analyzed in duplicate for Lead using EPA Method 6010A, Inductively Coupled Plasma-Atomic Emission Spectroscopy after digestion by EPA Method 3050A, Acid Digestion of Sediments, Sludges and Soils. A two-way ANOVA of the resulting data showed that the within and between vial analyses could be considered equivalent. Although the CV of the pooled data from these tests was 76%, because all results were near the method detection limit, the observed variability is most likely due to measurement method imprecision and not product inhomogeneity. Therefore, the product is considered homogeneous in that essentially no Lead was detected. Two additional vials were analyzed in duplicate using EPA Method 7420, Lead (Atomic Absorption, Direct Aspiration) also after digestion using Method 3050A. The mean values of the results of these analyses and those from Method 6010A were found to not differ statistically. The results of the 10 determinations were pooled and the 95% prediction interval calculated. The certified value for Lead is the mean value of these determinations ± the uncertainty for the 95% prediction interval. Laboratories should be able to obtain results for Lead within the range 0 to 21 mg/kg using these methods and a 0.5 g sample size. Use of smaller or larger sample sizes will potentially result in different detection limits and the acceptance range may need to be changed accordingly.

This material is intended to be used as a quality control standard in performing tests for Lead in soil by EPA Methods 6010A and 7420 and ASTM Method E1613-94. Tests for stability will be performed as necessary. Any changes in the certified value outside the 95% prediction interval will be reported to purchasers of this product. The product does not require any additional homogenization and there are no special storage requirements.

Approved by:

________________________ ___________

Alvia Gaskill, Jr., President Date

ENVIRONMENTAL REFERENCE MATERIALS, INC.

P.O. BOX 12527 RESEARCH TRIANGLE PARK, N.C. 27709 1-919-544-1669 1-888-OIL-SOIL

CERTIFICATE OF ANALYSIS

LEAD FREE SOIL

CAT. NO. ERM-7a

LOT NO. 7-02-1

DATE OF MANUFACTURE: 10-8-02

EXPIRATION DATE: 10-8-12

REVISION 1: 1-12-05

CERTIFIED VALUE FOR LEAD: <4.2 mg/kg

DESCRIPTION AND INTENDED USE:

A clean clay soil from land under development in an industrial park was sieved to pass a 177-micron sieve and blended. The product was packaged sequentially in 50 g units in glass jars. Units from the beginning, middle and end of the packaging sequence were analyzed in triplicate for Lead using EPA Method 6010A, Inductively Coupled Plasma-Atomic Emission Spectroscopy after digestion by EPA Method 3050A, Acid Digestion of Sediments, Sludges and Soils. A two-way ANOVA of the resulting data showed that the within and between jar analyses could be considered equivalent. All of the results were below the method detection limit of 4.2 mg/kg. Therefore, the product is considered homogeneous with respect to Lead. The results of the 14 determinations were pooled and the 95% prediction interval calculated. The certified value is the mean value of these determinations ± the uncertainty for the 95% prediction interval, which in this case, is zero. Laboratories should be able to obtain similar results using this method and a 0.5 g sample size. Use of smaller or larger sample sizes will potentially result in different detection limits and the acceptance range may need to be changed accordingly. This material was also analyzed for Lead along with NIST SRM 2709, San Joaquin Soil. The results of three determinations were all below the detection limit of 4.2 mg/kg. The certified value for Lead in this SRM is 18.9 mg/kg, but is based on a total digestion using hydrofluoric as well as nitric and hydrochloric acids. Information values presented from digestions by Method 3050, an incomplete dissolution procedure using only nitric and hydrochloric acids, showed a range of 12-18 mg/kg. Because the SRM’s certified and information values are also close to typical detection limits for soils, the results for ERM-7a can be considered NIST traceable for Lead.

This material is intended to be used as a quality control standard in performing tests for lead in soil by EPA Methods 6010A and 7420 and ASTM Method E1613-94. Tests for stability will be performed as necessary. Any changes in the certified value outside the 95% prediction interval will be reported to purchasers of this product. The product does not require any additional homogenization and there are no special storage requirements.

Approved by:

________________________ ___________

Alvia Gaskill, Jr., President Date

ENVIRONMENTAL REFERENCE MATERIALS, INC.

P.O. BOX 12527 RESEARCH TRIANGLE PARK, N.C. 27709 1-919-544-1669 1-888-OIL-SOIL

CERTIFICATE OF ANALYSIS

LOW LEVEL LEAD IN PAINT

CAT. NO. ERM-8b

LOT NO. 8-07-1

DATE OF MANUFACTURE: 3-27-07

EXPIRATION DATE: 3-27-17

REVISION 1: 12-12-07

CERTIFIED VALUE FOR LEAD: 645.9 ± 68.2 mg/kg

GRAVIMETRIC VALUE FOR LEAD: 607.8 mg/kg

DESCRIPTION AND INTENDED USE:

Lead containing house paint and Lead free paint were milled, sieved to pass a 180-micron sieve and blended together. The product was packaged sequentially in 10g units in glass vials. Units from the beginning, middle and end of the packaging sequence were analyzed for Lead using EPA Method 7420, Lead (Atomic Absorption, Direct Aspiration) after digestion by EPA Method 3050B, Acid Digestion of Sediments, Sludges and Soils. A two-way ANOVA of the resulting data showed that the within and between vial analyses could be considered equivalent. The CV of the pooled data from these tests was 4.8%. Based on these analyses, the product was judged to be homogeneous with respect to Lead. The results of the 15 determinations were pooled and the 95% prediction interval calculated. The certified value for Lead is the mean value of these determinations ± the uncertainty for the 95% prediction interval. Laboratories should be able to obtain results for Lead within this interval using this method and a 0.5g sample size. This material was also analyzed for Lead along with NIST SRM 2582, Powdered Paint. The mean of the results of three determinations for Lead in SRM 2582 was 240.3mg/kg, 115.1% of the certified value for Lead of 208.8mg/kg. Because of the agreement with the certified value for the SRM, the results for ERM-8b can be considered NIST traceable for Lead. In addition, two analyses of the NIST traceable CRM LCS-401, Blended Paints from Public Buildings gave a mean of 4538mg/kg, 102.4% of the certified value of 4430mg/kg. Because this product was prepared by blending together paints of known content, a gravimetric expected value can also be calculated. The gravimetric value, 607.8mg/kg is also within the 95% prediction interval. The certified value is 6.3% higher than the gravimetric value.

This material is intended for use as a quality control standard in performing tests for Lead in paint by EPA Methods 6010 and 7420 and ASTM Method E1613-94. Results also apply to digestions performed using EPA Methods 3050A and 3051. Tests for stability will be performed as necessary. Any changes in the certified value outside the 95% prediction interval will be reported to purchasers of this product. The product does not require any additional homogenization and there are no special storage requirements.

Approved by:

________________________ ___________

Alvia Gaskill, Jr., President Date

ENVIRONMENTAL REFERENCE MATERIALS, INC.

P.O. BOX 12527 RESEARCH TRIANGLE PARK, N.C. 27709 1-919-544-1669 1-888-OIL-SOIL

CERTIFICATE OF ANALYSIS

LOW LEVEL LEAD IN PAINT

CAT. NO. ERM-8c

LOT NO. 8-08-1

DATE OF MANUFACTURE: 5-27-08

EXPIRATION DATE: 5-27-18

CERTIFIED VALUE FOR LEAD: 577.1 ± 73.5 mg/kg

GRAVIMETRIC VALUE FOR LEAD: 598.3 mg/kg

DESCRIPTION AND INTENDED USE:

Lead containing house paint and Lead free paint were milled, sieved to pass a 150-micron sieve and blended together. The product was packaged sequentially in 50g units in glass jars. Units from the beginning, middle and end of the packaging sequence were analyzed for Lead using EPA Methods 7420, Lead (Atomic Absorption, Direct Aspiration) and Method 6010B, Inductively Coupled Plasma-Atomic Emission Spectroscopy after digestion by EPA Method 3050B, Acid Digestion of Sediments, Sludges and Soils. A two-way ANOVA of the resulting data from Method 6010B showed that the within and between jar analyses could be considered equivalent. The CV of the pooled data from Method 6010B was 4.4%. Based on these analyses, the product was judged to be homogeneous with respect to Lead. Additional statistical analyses showed the Method 7420 and 6010B data could be considered equivalent. The results of the 13 determinations were pooled and the 95% prediction interval calculated. The certified value for Lead is the mean value of these determinations ± the uncertainty for the 95% prediction interval. Laboratories should be able to obtain results for Lead within this interval using this method and a 0.5g sample size. This material was also analyzed for Lead along with NIST SRM 2582, Powdered Paint. A single determination using Method 7420 gave a result of 241mg/kg, 115.4% of the certified value of 208.8mg/kg. The mean of the results of three determinations for Lead in SRM 2582 by Method 6010B was 187.0mg/kg, 90.0% of the certified value. Because of the agreement with the certified value for the SRM, the results for ERM-8c can be considered NIST traceable for Lead. In addition, a single analysis of the NIST traceable CRM LCS-401, Blended Paints from Public Buildings by Method 7420 gave a result of 4457mg/kg, 100.6% of the certified value of 4430mg/kg. Because this product was prepared by blending together paints of known content, a gravimetric expected value can also be calculated. The gravimetric value, 598.3mg/kg is also within the 95% prediction interval. The certified value is 3.5% lower than the gravimetric value.

Approved by:

________________________ ___________

Alvia Gaskill, Jr., President Date

ENVIRONMENTAL REFERENCE MATERIALS, INC.

P.O. BOX 12527 RESEARCH TRIANGLE PARK, N.C. 27709 1-919-544-1669 1-888-OIL-SOIL

CERTIFICATE OF ANALYSIS

LEAD PAINT IN SOIL

CAT. NO. ERM-9

LOT NO. 9-97-1

DATE OF MANUFACTURE: 9-9-97

EXPIRATION DATE: 9-9-07

REVISION 1: 1-12-05

CERTIFIED VALUE FOR LEAD: 558 ± 39 mg/kg

DESCRIPTION AND INTENDED USE:

Soil containing Lead paint was sieved to pass a 177-micron sieve and blended with clean base soil. The product was packaged sequentially in 5 g units in 7-mL glass vials. Five units from the beginning, middle and end of the packaging sequence were analyzed in duplicate for Lead using EPA Method 6010A, Inductively Coupled Plasma-Atomic Emission Spectroscopy after digestion by EPA Method 3050A, Acid Digestion of Sediments, Sludges and Soils. A two-way ANOVA of the resulting data showed that the within and between vial analyses could be considered equivalent. The CV of the pooled data from these tests was 2.3%. Based on these analyses, the product was considered homogeneous for Lead. The same units were also analyzed in duplicate using EPA Method 7420, Lead (Atomic Absorption, Direct Aspiration) also after digestion using Method 3050A. The mean values of the results of these analyses and those from Method 6010A were found to not differ statistically. The results of the 20 determinations were pooled and the 95% prediction interval calculated. The certified value for Lead is the mean value of these determinations ± the uncertainty for the 95% prediction interval. Laboratories should be able to obtain results for Lead within this interval.

Approved by:

________________________ ___________

Alvia Gaskill, Jr., President Date

ENVIRONMENTAL REFERENCE MATERIALS, INC.

P.O. BOX 12527 RESEARCH TRIANGLE PARK, N.C. 27709 1-919-544-1669 1-888-OIL-SOIL

CERTIFICATE OF ANALYSIS

LEAD PAINT IN SOIL

CAT. NO. ERM-9a

LOT NO. 9-02-1

DATE OF MANUFACTURE: 10-8-02

EXPIRATION DATE: 10-8-12

REVISION 1: 1-12-05

CERTIFIED VALUE FOR LEAD: 483.6 ± 48.9 mg/kg

DESCRIPTION AND INTENDED USE:

Soil containing lead paint was sieved to pass a 177-micron sieve and blended with clean base soil. The product was packaged sequentially in 50 g units in glass jars. Units from the beginning, middle and end of the packaging sequence were analyzed in triplicate for Lead using EPA Method 6010A, Inductively Coupled Plasma-Atomic Emission Spectroscopy after digestion by EPA Method 3050A, Acid Digestion of Sediments, Sludges and Soils. A two-way ANOVA of the resulting data showed that the within and between jar analyses could be considered equivalent. The CV of the pooled data from these tests was 4.5%. Based on these analyses, the product was judged to be homogeneous with respect to Lead. The results of the 14 determinations were pooled and the 95% prediction interval calculated. The certified value for Lead is the mean value of these determinations ± the uncertainty for the 95% prediction interval. Laboratories should be able to obtain results for Lead within this interval using this method and a 0.5 g sample size. This material was also analyzed along with NIST SRM 2586, Trace Elements in Soil Containing Lead from Paint. The mean of the results of three determinations was 401.9 mg/kg, 93% of the certified value for Lead of 432 mg/kg. Because of the close agreement with the certified value for the SRM, the results for ERM-9a can be considered NIST traceable for Lead.

Approved by:

________________________ ___________

Alvia Gaskill, Jr., President Date

ENVIRONMENTAL REFERENCE MATERIALS, INC.

P.O. BOX 12527 RESEARCH TRIANGLE PARK, N.C. 27709 1-919-544-1669 1-888-OIL-SOIL

CERTIFICATE OF ANALYSIS

LEAD PAINT IN SOIL

CAT. NO. ERM-12a

LOT NO. 12-07-1

DATE OF MANUFACTURE: 5-24-07

EXPIRATION DATE: 5-24-17

REVISION 1: 6-13-07

CERTIFIED VALUE FOR LEAD: 5273 ± 412 mg/kg

GRAVIMETRIC VALUE FOR LEAD: 5635 mg/kg

DESCRIPTION AND INTENDED USE:

Soil containing lead paint was sieved to pass a 177-micron sieve and blended with other soils containing lead paint, lead paint and clean base soil. The product was packaged sequentially in 25g units in glass vials. Units from the beginning, middle and end of the packaging sequence were analyzed for Lead using EPA Method 7420, Lead (Atomic Absorption, Direct Aspiration) after digestion by EPA Method 3050B, Acid Digestion of Sediments, Sludges and Soils. A two-way ANOVA of the resulting data showed that the within and between vial analyses could be considered equivalent. The CV of the pooled data from these tests was 3.5%. Based on these analyses, the product was judged to be homogeneous with respect to Lead. The results of the 15 determinations were pooled and the 95% prediction interval calculated. The certified value for Lead is the mean value of these determinations ± the uncertainty for the 95% prediction interval. Laboratories should be able to obtain results for Lead within this interval using this method and a 0.5g sample size. This material was also analyzed along with NIST SRM 2586, Trace Elements in Soil Containing Lead from Paint. The mean of the results of three determinations for Lead in SRM 2586 was 373.3mg/kg, 86.4% of the certified value for Lead of 432mg/kg. Because of the agreement with the certified value for the SRM, the results for ERM-12a can be considered NIST traceable for Lead. Because this product was prepared by blending together soils and paint of known content, a gravimetric expected value can also be calculated. The gravimetric value, 5635mg/kg is also within the 95% prediction interval. The certified value is 6.4% lower than the gravimetric value.

This material is intended for use as a quality control standard in performing tests for Lead in soil by EPA Methods 6010 and 7420 and ASTM Method E1613-94. Results also apply to digestions performed using EPA Methods 3050A and 3051. Tests for stability will be performed as necessary. Any changes in the certified value outside the 95% prediction interval will be reported to purchasers of this product. The product does not require any additional homogenization and there are no special storage requirements.

Approved by:

________________________ ___________

Alvia Gaskill, Jr., President Date

RESEARCH TRIANGLE INSTITUTE

P.O. BOX 12194 RESEARCH TRIANGLE PARK, N.C. 27709-2194 1-919-541-6883

CERTIFICATE OF ANALYSIS

NORTHEAST URBAN SOIL

CAT. NO. LCS-301

LOT NO. 301-98-1

DATE OF MANUFACTURE: 5-98

EXPIRATION DATE: 5-31-12

REVISION 1: 12-15-04

CERTIFIED VALUE FOR LEAD: 547.1 ± 41.2 mg/kg

DESCRIPTION AND INTENDED USE:

The material used in this reference material was prepared according to procedures developed and used by Research Triangle Institute (RTI) for its preparation of Environmental Lead Proficiency Analytical Testing (ELPAT) materials for the American Industrial Hygiene Association and also Standard Operating Procedures for Preparation of Lead in Paint and Lead in Dust prepared for the U.S. EPA (EPA 600/R-93/235, NTIS #PB94-141165; EPA 600/R-94/132, NTIS #PB95-174090; and EPA 600/R-94/146, NTIS #PB95-190427).

Soil containing lead paint from drip lines around pre-1978 houses was ball-milled, sieved to pass a 75µ sieve and blended in a V shell mixer. The product was packaged sequentially in 50 g units in glass bottles. Around 10% of all units from the beginning, middle and end of the packaging sequence were analyzed in duplicate for Lead using EPA Method 6010B, Inductively Coupled Plasma-Atomic Emission Spectroscopy after digestion by EPA Method 3050A, Acid Digestion of Sediments, Sludges and Soils and EPA Method 3051, Microwave Assisted Acid Digestion of Sediments, Sludges, Soils and Oils. A two-way ANOVA of the resulting data showed that the within and between bottle analyses could be considered equivalent. Additional statistical analyses showed the Method 3050A and 3051 data could be considered equivalent. The CV of the pooled data from these tests was 3.7%. Based on these analyses, the product was judged to be homogeneous for Lead. The results of the 70 determinations were pooled and the 95% prediction interval calculated. The certified value for Lead is the mean value of these determinations ± the uncertainty for the 95% prediction interval. Laboratories should be able to obtain results for Lead within this interval using this method and a 0.5 g sample size. This material was also analyzed along with NIST SRM 2704, Buffalo River Sediment. The mean of the results of six determinations was 163 mg/kg, 101% of the certified value for Lead of 161 mg/kg. Because of the close agreement with the certified value for the SRM, the results for LCS-301 can be considered NIST traceable for Lead. Results for additional NIST and non-NIST traceable elements are given on the following pages.

This material is intended to be used as a quality control standard in performing tests for Lead and other elements in soil by EPA Methods 6010B and 7420 and ASTM Method E1613-94. Tests for stability will be performed as necessary. Any changes in the certified value outside the 95% prediction interval will be reported to purchasers of this product. The product does not require any additional homogenization and there are no special storage requirements.