# ChesHaz vs Decon Field Guide

The clearest difference is review sentiment: ChesHaz at 100% against Decon Field Guide's 0%. ChesHaz also leads on rating (5.0 vs 4.6) and monetization model (free vs ad-supported). On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ChesHaz holds the better App Store score, 5.0 against 4.6. Both are backed by a comparable volume of ratings — 4 and 8 respectively. Written reviews point the same way: 100% of ChesHaz's written reviews are positive against 0% of Decon Field Guide's.

ChesHaz ships an update every 6 weeks, Decon Field Guide every 2 months. The most recent releases landed on October 7, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | ChesHaz | Decon Field Guide |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/cheshaz/id1320963064/reviews)** | [4.6 (8 ratings)](https://appshunter.io/ios/app/decon-field-guide/id1388378944/reviews) |
| Number of ratings | 4 | **8** |
| Positive reviews | **100.0% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 weeks** | Every 2 months |
| Monetization | **Free** | Ad-supported |
| Size | 3 MB | 74 MB |
| Requires iOS | **10.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [WIlliam Cheswick](https://appshunter.io/developer/419708950) | [First Line Technology](https://appshunter.io/developer/1388378943) |

## What reviewers say

### ChesHaz

[App page](https://appshunter.io/ios/app/cheshaz/id1320963064)

Quickly identify hazardous materials using four-digit UN/NA numbers found on placards. Access chemical names and additional information offline. Links to external resources provide further details.

**Highlights:** Offline UN/NA number lookup, Chemical name display, Links to Wikipedia, Links to NOAA information, Educational purposes

**Features:** macOS Compatibility

**In-app purchases:** none


### Decon Field Guide

[App page](https://appshunter.io/ios/app/decon-field-guide/id1388378944)

This reference app provides quick and efficient decontamination methods for hundreds of threats. It features a classic Threat Index, pictorial instructions, and an in-app dwell timer to guide users through mission execution. Designed for approved users, it aims to make anyone an instant decontamination expert.

**Highlights:** Threat Index for decontamination methods, Pictorial instructions, In-app dwell timer, Covers hundreds of threats, Designed for approved users

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is ChesHaz free?

ChesHaz is free to download, with no in-app purchases.

### Is Decon Field Guide free?

Decon Field Guide is free to download, with no in-app purchases.

### Which has better reviews, ChesHaz or Decon Field Guide?

ChesHaz is rated higher. ChesHaz averages 5.0 out of 5 from 4 ratings, while Decon Field Guide averages 4.6 from 8 ratings.

### Do ChesHaz or Decon Field Guide have ads?

Neither ChesHaz nor Decon Field Guide shows ads.

### Which is updated more often, ChesHaz or Decon Field Guide?

ChesHaz ships an update every 6 weeks, and Decon Field Guide every 2 months. Most recently, ChesHaz was updated on October 7, 2026 and Decon Field Guide on October 25, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*