Texas Comptroller of Public Accounts

Texas Comptroller of Public Accounts, Glenn Hegar

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Texas Specification No. 505-57-01A

Effective Date: April 29, 1981

Reformatted: January 29, 1996




1. SCOPE: This specification covers the minimum requirements for a two grades of sodium metasilicate (Na2SiO3) for use primarily as an alkaline builder in laundry operations.

2. APPLICABLE SPECIFICATIONS AND STANDARDS: References to specifications, standards and test methods shall be to the issues in effect on the date of the Invitation for Bids. Copies of the referenced documents may be obtained from the issuing organizations at the addresses shown. The following documents form a part of this specification to the extent specified herein:

2.1. AMERICAN SOCIETY FOR TESTING MATERIALS, 1916 Race Street, Philadelphia, PA 19103:

2.1.1. ASTM D 501 -- Standard Methods of Sampling and Chemical Analysis of Soaps and Other Detergents.

2.1.2. ASTM D 502 -- Standard Method of Test for Particle Size of Soaps and Other Detergents.

2.1.3. ASTM D 1172 -- Standard Method of Test for pH of Aqueous Solutions of Soaps and Detergents.

2.2. LINEN SUPPLY ASSOCIATION OF AMERICA, 1250 East Hallandale Beach Boulevard, Hallandale, FL 33009:

2.2.1. Textile Laundering Technology, 1979, by Riggs, Charles L. and sherrill, Joseph C.

2.3. TEXAS SPECIFICATIONS: General Services Commission, P.O. Box 13186, Austin, TX 78711:

2.2.1. Texas Specification No. 505-57-03B-- Laundry Alkali -- "Sodium Orthosilicate".

3. DEFINITIONS: Terminology used in this specification is intended to be generic in nature and consistent with meanings that have been defined through general use and/or accepted trade practices. Where variant meanings may exist, the applicable interpretation shall be determined by the Texas Procurement and Support Services (TPASS).

3.1. Commission: Texas Procurement and Support Services (TPASS).

4. REQUIREMENTS: Sodium metasilicate furnished under this specification shall meet or exceed the following minimum requirements for Grade A or Grade B material, whichever is specified in the Invitation for Bids:

4.1. General Requirements:

4.1.1. Grade A (Anhydrous): The product shall be a free flowing granular material, white or bluish-white in color.

4.1.2. Grade B (Hydrated): The product shall be in granular or bead from. when dispersed from the original container, it shall not give rise to clouds of irritating dust particles.

4.2. Chemical and Physical Requirements: The properties listed in Table 1 shall conform to the given requirements when tested by the methods cited in Section 6 or approved equally applicable procedures.



Requirement Grade A Minimum Grade A Maximum Grade B Minimum Grade B Maximum Test Paragraph
1. Total alkalinity as Na2O, pbw* 50.00 52.00 29.00 30.00 6.1
2. Silica as SiO2, pbw* 45.00 48.00 28.00 29.00 6.2
3. Carbonate as CO2, pbw* -- 2.0 -- 1.0 6.3
4. Water insoluble matter, pbw* -- 0.3 -- 0.1 6.40
5. pH in 1% aqueous solution 12.4 -- 12.4 -- 6.5
6. Particle size, pbw* passing
No. 10 standard sieve

(2.00 mm)

99.00 -- 98.00 -- 6.60
No. 100 standard sieve

(150 mm)

-- 2.00 -- 1.00 6.60
*pbw: percent by weight

5. SAMPLES: Unless otherwise specified in the Invitation for Bids, no prepurchase samples shall be required. Samples tested shall be taken from regular orders.

6. TESTING: Testing shall be done by or at the direction of, the Commission and/or the receiving State agency. Tests shall be performed on products from shipments to ordering agencies. In the event products tested fail to meet or exceed all conditions and requirements of this specification, the cost of the samples used and the cost of testing shall be borne by the supplier.

6.1. TESTS: The product furnished under this specification shall be tested by the following methods or equally applicable procedures:

6.1.1. Total Alkalinity: Determine compliance with Paragraph 4.2. by the procedure of ASTM 501, Paragraphs 47 through 49.

6.1.2. Silica: Determine compliance with Paragraph 4.2 by the procedure of ASTM D 501, Paragraphs 50 through 52.

6.1.3. Carbonate: Determine compliance with Paragraph 4.2 by the procedure of ASTM D 501, Paragraphs 12 through 15.

6.1.4. Water Insoluble Matter: Determine compliance with Paragraph 4.2 by the procedure of ASTM D 501, Paragraphs 55 and 56.

6.1.5. pH: Determine compliance with Paragraph 4.2 by the procedure of ASTM D 1172, with the exception that a 10 gram sample weighed to the nearest 0.1 gram shall be used.

6.1.6. Particle Size: Determine the compliance with Paragraph 4.2 by the procedure of ASTM D 502, with the exception of the screen sizes required.

7. INSPECTION: Products furnished under this specification shall be inspected by, or at the direction of the Commission and/or the ordering State agency either at the destination or place of manufacture.

8. PACKING / PACKAGING: Packing for shipment shall be in accordance with the manufacturer's standard practice and in a manner readily accepted by common carriers engaged in interstate commerce. Within the shipping carton, units shall be packed in a manner designed to minimize damage during the shipment because of rough or improper handling.

8.1. PACKING: The product shall be packaged fro shipment in one of the following types of containers, whichever is specified in the Invitation for Bids:

8.1.1. 100 pound (45.4 kg) moisture resistant multiwall paper bags.

8.1.2. 400 pound (182 kg) plastic lined fiber drums approved by the Department of Transportation.


9.1. MARKING: Each shipping container shall be clearly marked with the following:

9.1.1. Name of product, including trade name if any.

9.1.2. Quantity contained in pounds and/or kilograms.

9.1.3. Name and address of the manufacturer.

9.1.4. Warning statements as required by government regulations.

The following information shall either be marked on the container or appear on the shipping documents:

9.1.5. Order number or contract number.

9.1.6. Name and address of ordering agency.

9.1.7. Agency requisition number.

10. COMPLIANCE: In order for consideration to be given to the bid on an item under this specification, the bidder must comply with the following:

10.1. PRODUCT IDENTIFICATION: The make, model number, name of the manufacturer, brand or trade name, etc., as applicable, of the item which the vendor proposes to furnish must be stated as part of the bid.

10.2. EXCEPTIONS: Notwithstanding the above, any exception taken by the bidder to the requirements and conditions of this specification must be stated and described in detail as a part of the bid. If no exceptions or deviations are identified in this manner, the items must be furnished exactly as described herein.

10.3. PROOF: The bidder shall bear the burden of proof of compliance with this specification.

11. ORDERING DATA: When ordering products conforming to this specification the requisitioning agency shall specify the following:

11.1. The number of this specification (505-57-01A).

11.2. The grade required (A or B).

11.3. The size and type of container required.

11.4. The total quantity required.

Note: Before ordering, the requisitioning agency should consider both the safety and the cost effectiveness factors discussed in Paragraph 12.


12.1. Grade A (Anhydrous): This laundry alkali provides a little less active alkalinity at a lower pH than an equal amount by weight of sodium orthosilicate (Texas Specifications No. 505-57-3B, Grade A). Due to its superior emulsifying and suspending ability, it is the builder of choice for laundering fabrics soiled with mineral oils and greases (Ref. Riggs and Sherrill, p. 47). Although it is not quite so caustic to body tissues as orthosilicate, this product should be handled with the same precautions against contact with the eyes or skin. Any accidental contact should be promptly treated by prolonged flushing with running water. Recommended first aid for swallowing is the drinking of lots of water followed by an ounce of vinegar diluted with water. Call a physician immediately.

12.2. Grade B (Hydrated): Sodium metasilicate pentahydrate has a crystal structure which gives it less tendency than Grade A to from irritating dust clouds. It also has less irritant effect on the skin, and dissolves faster in water. These advantages must be weighed against a higher effective cost. Although Grade B has a lower price per pound, its active alkali (Na2O) content is so much lower than about 75% more must be added to the break suds to get the same strength sodium metasilicate solution.

Like all laundry alkalis, both grades of sodium metasilicate should be stored in a tightly closed container. Otherwise, they will lose strength by absorption of moisture and carbon dioxide from the air.

13. AVAILABILITY OF SPECIFICATIONS: Copies of this specification may be obtained by calling or writing:

Bid Services

Texas Procurement and Support Services

P.O.Box 13186

Austin, TX 78711-3047

(512) 463-3416

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