Quality Evaluation of Some Laundry Soaps Sold in Markets of Port Harcourt, Rivers State, Nigeria
Open accessAbstract
Ten commercial laundry soaps were evaluated for their physicochemical properties... pH ranged from 9.5 to 11.0, moisture content varied from 15.2 to 23.6%, free caustic, total fatty matter, and chloride ranged from 0.04 to 0.26%, 42.3 to 52.0%, and 0.8 to 3.2 %, respectively... Foam value and stability ranged from 69 to 82.
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Written from the paper’s full text.
TL;DR
Ten laundry soap brands bought in Port Harcourt markets were assessed for physical and chemical quality against Nigerian and related standards. Many samples fell outside expected limits, particularly for weight, total fatty matter, and chloride, although the paper’s own statements about total fatty matter compliance conflict.
Key findings
- Reported ranges were pH 9.5–11.0; moisture 15.2–23.6% in the abstract, with the results table showing up to 25.0%; free caustic alkali 0.04–0.26%; total fatty matter 42.3–52.0%; chloride 0.8–3.2%; alcohol-insoluble matter 1.5–3.0%; water-insoluble matter 0.8–1.5%; foam value/stability 69–82; and rate of wear 8–25%.
- All ten brands differed from their declared weights, with actual weights lower in every listed case, such as 70 g declared versus 66 g actual for sample A and 75 g declared versus 65 g actual for sample I. All samples were hard, passed the staining test, and showed no cracking.
- Against NIS limits, all samples were below the stated 62% minimum for total fatty matter, and samples A, C, D, E, and J exceeded the 1.5% maximum for chloride. The text says samples B, D, and F exceeded the 0.2% free caustic alkali limit, but the table shows B, D, and F below that value while A, C, G, and J are at or above it.
- The conclusion states that all brands complied with the total fatty matter minimum, which contradicts the earlier statement that all failed that requirement.
Methods
- Ten commercial laundry soaps labeled A–J were purchased from markets in Port Harcourt, Rivers State, Nigeria, grated, stored in airtight containers at ambient temperature, and analyzed at Rivers State University.
- Standard methods from AOAC, AOCS, NIS, and East African Standard were used to assess declared and actual weight, hardness, perfume, colour, staining, cracking, foam stability, rate of wear, pH, moisture, free caustic alkali, total fatty matter, chloride, and alcohol- and water-insoluble matter.
- pH was measured on 10% soap solutions with a pH meter, moisture by oven drying at 105 °C, total fatty matter by acid hydrolysis and ether extraction, and chloride by titration; pH measurements were done in triplicate.
Limitations
- The paper does not explicitly list limitations; it recommends regular regulatory quality checks on laundry soaps sold in markets.
- Evident from the text: the reporting contains contradictions, especially for total fatty matter compliance and for which samples exceeded the free caustic alkali limit.
- Evident from the text: some method descriptions and formulas are truncated or incomplete, and the sample covers only ten brands from one market area, limiting broader generalization.
Model-written summary. Check it against the paper before relying on it.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
0 of 1 cited sources checked · 0 supported · 0 flagged
- Findingown data
Most soap samples had alcohol-insoluble matter over 2.5%.
“Most of the soap samples ar e highly filled with insoluble mat ter in alcohol and water (over 2.5% and 0.50% respectively)”
Quote in the paperSubstantial claim - Findingown data
The moisture content of the laundry soaps ranged between 15.2 and 25.0%.
“The moisture content of the laundry soaps ranged between 15.2 and 25.0 %.”
Quote in the paperSubstantial claim - Findingown data
The pH of the ten laundry soaps ranged from 9.5 to 11.0.
“Results showed that pH ranged from 9.5 to 11.0”
Quote in the paperNot a substantial claim - Findingown data
Samples C, E, and G had a pH of 11.0.
“The pH values for the soap samples are within the range, except for C, E, and G samples, which had a pH of 11.0.”
Quote in the paperNot a substantial claim - Findingown data
The moisture content of the ten laundry soaps varied from 15.2 to 23.6%.
“moisture content varied from 15.2 to 23.6%”
Quote in the paperNot a substantial claim
- Findingown data
All ten soap brands were hard.
“It was observed that all the soap brands are hard.”
Quote in the paperNot a substantial claim - Findingown data
The free caustic content of the ten laundry soaps ranged from 0.04 to 0.26%.
“free caustic, total fatty matter, and chloride ranged from 0.04 to 0.26%, 42.3 to 52.0%, and 0.8 to 3.2 %, respectively.”
Quote in the paperNot a substantial claim - Findingown data
The alcohol insoluble matter of the ten laundry soaps varied from 1.5 to 3.0%.
“alcohol insoluble matter and water insoluble varied from 1.5 to 3.0% and 0.8 to 1.5 %, respectively.”
Quote in the paperNot a substantial claim - Findingown data
Samples A, C, D, E, and J had chloride content above the maximum permissible limit.
“The values obtained for samples A, C, D, E, and J were all above the maximum permissible limit.”
Quote in the paperSubstantial claim - Findingnone given
All brands complied with the minimum requirement for total fatty matter.
“All the brands complied with the minimum requirement for total fatty matter .”
Quote in the paperNot a substantial claim - Findingown data
All soap samples except C, E, and G had pH values within the NIS range.
“The pH values for the soap samples are within the range, except for C, E, and G samples, which had a pH of 11.0.”
Quote in the paperNot a substantial claim - Findingown data
All brands failed to comply with the NIS minimum requirement for total fatty matter.
“however, all the brands failed to comply with the minimum requirement of total fatty matter”
Quote in the paperSubstantial claim - Findingown data
The moisture content of the laundry soaps is lower than the 29.05% reported for black soap by earlier researchers.
“The moisture content is lower than the 29.05% obtained by some earlier researchers for black soap [20].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [20] 20. Ogunsuyi HO & Akinawo CA, (2012). Quality assessment of soaps produced from Palm bunch ash derived from Kali and coconut. Journal of Applied Science and Environmental Management. 16: 363-366.
Not checked in the free run.
- Findingown data
Most soap samples had water-insoluble matter over 0.50%.
“Most of the soap samples ar e highly filled with insoluble mat ter in alcohol and water (over 2.5% and 0.50% respectively)”
Quote in the paperSubstantial claim - Findingown data
The chloride content of the ten laundry soaps ranged from 0.8 to 3.2%.
“free caustic, total fatty matter, and chloride ranged from 0.04 to 0.26%, 42.3 to 52.0%, and 0.8 to 3.2 %, respectively.”
Quote in the paperNot a substantial claim - Findingown data
The total fatty matter of the ten laundry soaps ranged from 42.3 to 52.0%.
“free caustic, total fatty matter, and chloride ranged from 0.04 to 0.26%, 42.3 to 52.0%, and 0.8 to 3.2 %, respectively.”
Quote in the paperNot a substantial claim - Findingown data
The rate of wear of the ten laundry soaps varied from 8 to 25%.
“the rate of wear varied from 8 to 25%”
Quote in the paperNot a substantial claim - Findingown data
The water insoluble matter of the ten laundry soaps varied from 0.8 to 1.5%.
“alcohol insoluble matter and water insoluble varied from 1.5 to 3.0% and 0.8 to 1.5 %, respectively.”
Quote in the paperNot a substantial claim - Findingown data
The foam value and stability of the ten laundry soaps ranged from 69 to 82.
“Foam value and stability ranged from 69 to 82”
Quote in the paperNot a substantial claim - Findingown data
All brands except samples B, D, and F had free caustic values lower than the NIS maximum limit.
“All the brands had values lower than t he maximum limit except for samples B, D, and F.”
Quote in the paperNot a substantial claim - Findingown data
All ten laundry soap samples failed the declared and actual weight tests.
“All the samples failed in the declared and actual tests.”
- Also stated in: § Additional information · plain
“All the brands of soap analyzed failed in declared and actual weight.”
- Also stated in: § Figures below · plain
“Soap weight of all the soap brands differed f rom the actual and declared weight.”
Quote in the paperSubstantial claim - Also stated in: § Additional information · plain
- Interpretationreasoning
The high insoluble matter is the reason for the decrease in the quality of the soap samples.
“This is the reason for the decrease in the quality of soap samples.”
Quote in the paperSubstantial claim - Interpretationreasoning
Most of the soaps analyzed will not favor the growth of microbes.
“This indicates that most of the soaps analyzed will not favor the growth of microbes.”
Quote in the paperNot a substantial claim - Interpretationreasoning
The high insoluble matter in alcohol and water results in mushiness and low total fatty matter.
“resulting in mushiness and low total fatty matter.”
Quote in the paperSubstantial claim - Premisenone given
According to NIS standards, laundry soap should have at least 62 percent minimum total fatty matter.
“According to NIS standards, laundr y soap should have at least 62 percent minimum”
Quote in the paperSubstantial claim - Interpretationown data
Many of the laundry soaps sold in Port Harcourt markets do not conform to the minimum standard recommended by the Nigerian Institute of Standards (NIS).
“The study revealed that many of the laundry soaps sold in the markets do not conform to the minimum standard recommended by the Nigerian Institute of Standards (NIS).”
Quote in the paperSubstantial claim
- Classified as probably not a substantial claim. 2
- May combine two claims. 1
Probably not a substantial claim: may not pass S4 (based).
Premisenone givenThe Nigerian Industrial Standards (NIS) requirement for free caustic content in laundry soap is 0.2 percent maximum.
“The Nigerian Industrial Standards (NIS) requirement for free caustic content in laundry soap is 0.2 percent maximum.”
Quote in the paperNot a substantial claimMay combine two claims.
InterpretationcitationTFM values are due to moisture, low fat, and the presence of unreacted alkali in the soap.
“TFM values are due to moisture, low fat, and the presence of unreacted alkali in the soap.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim.
Premisenone givenThe standard requirement for chloride content in laundry soap is 1.50 percent maximum.
“The standard requirement is 1.50 percent maximum.”
Quote in the paperSubstantial claim
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Conclusion reverses the total fatty matter finding
MajorThe discussion says every brand fails the 62% minimum, but the conclusion says every brand complies. Table 5 lists all ten values below 62%.
“All the brands complied with the minimum requirement for total fatty matter .”
“however, all the brands failed to comply with the minimum requirement of total fatty matter”
The chloride discussion misidentifies limit exceedances
MajorTable 5 gives a 1.50% maximum. Sample J is below it at 0.80%, whereas G, H, and I exceed it but are omitted from the stated list.
“The values obtained for samples A, C, D, E, and J were all above the maximum permissible limit.”
“CL (%) 2.00 1.20 2.80 2.40 3.20 1.20 2.00 1.60 2.35 0.80 1.50”
The free-caustic failures are assigned to the wrong samples
MajorAgainst the stated 0.20% maximum, Table 5 shows A, C, G, and J above the limit. The named exceptions B, D, and F are all below it.
“All the brands had values lower than t he maximum limit except for samples B, D, and F.”
“FCA (%) 0.25 0.15 0.26 0.15 0.04 0.18 0.22 0.16 0.20 0.25 0.20”
The pH discussion misses two samples above the stated range
MinorTable 5 gives an NIS range of 7-10. In addition to C, E, and G, samples H and I exceed that range, at 11.00 and 10.50.
“The pH values for the soap samples are within the range, except for C, E, and G samples, which had a pH of 11.0.”
“Parameters A B C D E F G H I J NIS pH 10.00 10.00 11.00 10.0 11.00 9.50 10.5 11.00 10.50 10.00 7-10”
Abstract understates the highest moisture content
MinorThe abstract gives 23.6% as the maximum moisture content, but Table 5 reports 25.00% for sample E.
“moisture content varied from 15.2 to 23.6%”
“MC (%) 22.80 22.30 23.60 22.8 25.00 21.50 18.6 19.30 20.40 15.20 10-30”
Abstract misstates the water-insoluble matter minimum
MinorThe abstract gives 0.8% as the minimum, but Table 5 reports 0.40% for sample D.
“alcohol insoluble matter and water insoluble varied from 1.5 to 3.0% and 0.8 to 1.5 %, respectively.”
“WIM (%) 1.50 0.80 0.70 0.40 0.70 0.80 1.00 1.10 1.12 0.80 0.50”
Abstract misstates the alcohol-insoluble matter range
MinorThe stated range is 1.5-3.0%, but Table 5 includes 1.20% for sample J and 3.20% for sample C.
“alcohol insoluble matter and water insoluble varied from 1.5 to 3.0% and 0.8 to 1.5 %, respectively.”
“AIM (%) 3.00 2.50 3.20 2.80 1.70 1.50 2.8 2.80 3.00 1.20 2.50”
Abstract omits the lowest total fatty matter value
MinorThe abstract gives 42.3% as the minimum, while Table 5 reports 41.85% for sample I.
“total fatty matter, and chloride ranged from 0.04 to 0.26%, 42.3 to 52.0%, and 0.8 to 3.2 %, respectively.”
“TFM (%) 42.30 48.00 45.00 48.00 46.0 50.0 44.7 45.00 41.85 52.0 62.0”
Cites
The publisher hasn’t deposited this paper’s reference list.
Research works printed but not linked: 7
- [1]1. Willcox, M. (2000). Soap in Hilda Butter: Pouchers Performes, Cosmetics, and Soap. 10th Edition, Dordrecht: Kluwer Academic, London. Pp 40-48.
- [3]3. Mohammed, U.F. & Usman, A. (2018). Physico-Chemical Analysis of Some Soaps Produced from Five Locally Processed Nigerian Oils. International Journal of Scientific and Engineering Research, 9, 531-539.
- [11]11. Tewari, K.S. (2004). Quality Assessment of Soaps. A Textbook of Chemistry. 3 rd Edition, Vikas Publishing House PVT Ltd., 26, 594- 600.
- [13]13. Betsy, K.J., Jilu, M., Fathima, R., & Varkey, J.T. (2013). Determination of Alkalinity Content & Total Fatty Matter in Cleansing Agents. Asian Journal of Science and Applied Technology. 2. 8-12.
- [19]19. American Oil Chemists'Society (AOCS). (2017). Official & Recommended Practices of the AOCS. 18th Edition, AOCS Press Publication, Champaign.
- [20]20. Ogunsuyi HO & Akinawo CA, (2012). Quality assessment of soaps produced from Palm bunch ash derived from Kali and coconut. Journal of Applied Science and Environmental Management. 16: 363-366.
- [21]21. Tewari, K.S.(2004).Quality Assessment of the Textbook of Chemistry. 3 rd Edition, Vikas Publishing House PVT Ltd., 26, 594 -600
Cited by
Sorted by citations
Dirahoui, M., Haddouchi, F., Mokrane-Aidat, R., Debbal, M., Rayane, B., & Brahmi, F. (2026) · International Journal of Computational and Experimental Science and Engineering · doi:10.22399/ijcesen.5198 · Cited by 1 · see citing works
- Authors
- Maduelosi, N. J., Okwechime, U. J., & Arodiogbu, F. U.
- Affiliations
- Rivers State University (NG)
- Venue
- ChemClass Journal
- Published
- 2025-05-25
- Volume
- 9
- Issue
- 2
- Pages
- 192-203
- ISSN
- 3092-8206 (ISSN-L)
- 3092-8214
- OpenAlex
- W4410915263
- Cited by
- 1
- References
- 0
- Citations by year
- 2026: 1
- FWCI
- 0.30
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- ChemClass Journal (publishedVersion)
- Topics
- Physical Sciences › Chemistry › Organic Chemistry › Surfactants and Colloidal Systems
- Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Pharmaceutical Quality and Counterfeiting
- Life Sciences › Agricultural and Biological Sciences › Food Science › Food Safety and Hygiene
- Keywords
- laundry soap, soap quality, physicochemical properties, free alkali, foam stability, moisture content, volatile matter, consumer goods, Port Harcourt
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Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-11.
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