What we observed

This is notably thin.

A Fortune article referencing declining bar soap sales, a dedicated bar soap market report (futuremarketinsights.com), and a dedicated liquid soap market report (persistencemarketresearch.com) together suggest that market researchers do track bar soap and liquid soap as distinct, separately sized categories — a structural precondition for any substitution narrative to be meaningful. Several additional items (markwideresearch.com, store.mintel.com, accio.com, knowledge-sourcing.com) are general soap-category market reports; they are adjacent to the topic but not specific evidence of a consumer preference shift toward liquid soap for hygiene reasons.

A further block of items — covering product life cycle decline stages, strategies for reviving declining products, and managing category decline generically (saasfactor.co, slm.mba, eleken.co, rajivgopinath.com, climbtheladder.com, linkedin.com, smartbrief.com) — are generic business/marketing management content with no specific reference to soap. These appear to have been linked because they discuss 'decline' in the abstract, likely surfaced by a research question about declining product categories rather than about liquid-versus-bar soap consumer behavior specifically.

But there is no item in this set that directly documents consumers explaining their preference in terms of 'perceived hygiene benefits' — the specific causal claim in the title remains unverified by the evidence supplied.

What is changing

The behavioural claim is a substitution: consumers moving away from bar soap, historically the default low-cost, low-packaging hygiene product, toward liquid soap and body wash formats. The stated rationale is a perception that liquid products are more hygienic, plausibly because they are dispensed rather than handled communally, reducing perceived risk of cross-contamination.

This is consistent with what is observable in the linked market reports: bar soap and liquid soap are treated as distinct product categories with separate market-sizing exercises, and at least one piece of business press coverage discusses bar soap sales decline. What is not observable from the current evidence is confirmation of the specific driver — hygiene perception — as opposed to other plausible explanations such as convenience, fragrance variety, premiumization, or retail merchandising shifts favoring pump bottles.

Why this matters

If a durable substitution from bar soap to liquid soap is occurring, it has real commercial consequences. Liquid soap products generally carry different cost structures — more packaging material (typically plastic bottles), different manufacturing and filling infrastructure, and often higher retail price points per use than bar soap. A shift in consumer preference at scale would affect raw material demand (plastics versus solid soap bases), retail shelf allocation, and the competitive dynamics between legacy bar soap brands and liquid/body-wash-focused brands.

It would also intersect with sustainability positioning: liquid soap in single-use plastic packaging sits in tension with broader anti-plastic and refill-economy trends, meaning that if this hygiene-driven substitution is real, it could create a secondary wave of innovation in refillable or concentrated liquid formats, or in solid soap reformulated to counter hygiene perception concerns (e.g., antimicrobial bar formulations). These are plausible second-order dynamics worth tracking, not confirmed outcomes.

How strong is the evidence

The evidence supporting this specific signal is weak and should be treated as such.

This is a case where the volume of linked items overstates the apparent evidentiary depth; a careful read narrows genuinely on-topic material to two or three items at most.

What we're watching next

For this signal to strengthen, Quettor would want to see: additional sources that directly link consumer-stated reasons (hygiene, convenience, price, fragrance) to the choice between bar and liquid soap, ideally from primary consumer research (surveys, retail panel data) rather than general market-sizing reports; corroborating signals from adjacent categories (e.g., hand sanitizer, dispenser adoption, antimicrobial product trends) that would support a hygiene-driven behavioral thread rather than a purely economic or convenience-driven one; and evidence of retail-level shifts, such as shelf-space reallocation or SKU rationalization by major retailers, which would provide harder proof of a real market substitution beyond stated preference.